原文出处：
iOS_小松哥（@小松哥之友情岁月）
在这里总结一些iOS开发中的小技巧，能大大方便我们的开发，持续更新。
UITableView的Group样式下顶部空白处理
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//分组列表头部空白处理
UIView *
view
=
[
[
UIView
alloc
]
initWithFrame
:
CGRectMake
(
0
,
0
,
0
,
0.1
)
]
;
self
.
tableView
.
tableHeaderView
=
view
;
|
UITableView的plain样式下，取消区头停滞效果
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-
(
void
)
scrollViewDidScroll
:
(
UIScrollView *
)
scrollView
{
CGFloat
sectionHeaderHeight
=
sectionHead
.
height
;
if
(
scrollView
.
contentOffset
.
y
=
0
)
{
scrollView
.
contentInset
=
UIEdgeInsetsMake
(
-
scrollView
.
contentOffset
.
y
,
0
,
0
,
0
)
;
}
else
if
(
scrollView
.
contentOffset
.
y
>=
sectionHeaderHeight
)
{
scrollView
.
contentInset
=
UIEdgeInsetsMake
(
-
sectionHeaderHeight
,
0
,
0
,
0
)
;
}
}
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那个，其实，还是用Group样式吧哈哈。
获取某个view所在的控制器
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-
(
UIViewController *
)
viewController
{
UIViewController *
viewController
=
nil
;
UIResponder *
next
=
self
.
nextResponder
;
while
(
next
)
{
if
(
[
next
isKindOfClass
:
[
UIViewController
class
]
]
)
{
viewController
=
(
UIViewController *
)
next
;
break
;
}
next
=
next
.
nextResponder
;
}
return
viewController
;
}
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两种方法删除NSUserDefaults所有记录
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//方法一
NSString *
appDomain
=
[
[
NSBundle
mainBundle
]
bundleIdentifier
]
;
[
[
NSUserDefaults
standardUserDefaults
]
removePersistentDomainForName
:
appDomain
]
;
//方法二
-
(
void
)
resetDefaults
{
NSUserDefaults *
defs
=
[
NSUserDefaults
standardUserDefaults
]
;
NSDictionary *
dict
=
[
defs
dictionaryRepresentation
]
;
for
(
id
key
in
dict
)
{
[
defs
removeObjectForKey
:
key
]
;
}
[
defs
synchronize
]
;
}
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打印系统所有已注册的字体名称
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#pragma mark - 打印系统所有已注册的字体名称
void
enumerateFonts
(
)
{
for
(
NSString *
familyName
in
[
UIFont
familyNames
]
)
{
NSLog
(
@
"%@"
,
familyName
)
;
NSArray *
fontNames
=
[
UIFont
fontNamesForFamilyName
:
familyName
]
;
for
(
NSString *
fontName
in
fontNames
)
{
NSLog
(
@
"\t|- %@"
,
fontName
)
;
}
}
}
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获取图片某一点的颜色
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-
(
UIColor*
)
getPixelColorAtLocation
:
(
CGPoint
)
point
inImage
:
(
UIImage *
)
image
{
UIColor*
color
=
nil
;
CGImageRef
inImage
=
image
.
CGImage
;
CGContextRef
cgctx
=
[
self
createARGBBitmapContextFromImage
:
inImage
]
;
if
(
cgctx
==
NULL
)
{
return
nil
;
/* error */
}
size
_t
w
=
CGImageGetWidth
(
inImage
)
;
size
_t
h
=
CGImageGetHeight
(
inImage
)
;
CGRect
rect
=
{
{
0
,
0
}
,
{
w
,
h
}
}
;
CGContextDrawImage
(
cgctx
,
rect
,
inImage
)
;
unsigned
char
*
data
=
CGBitmapContextGetData
(
cgctx
)
;
if
(
data
!=
NULL
)
{
int
offset
=
4
*
(
(
w*
round
(
point
.
y
)
)
+
round
(
point
.
x
)
)
;
int
alpha
=
data
[
offset
]
;
int
red
=
data
[
offset
+
1
]
;
int
green
=
data
[
offset
+
2
]
;
int
blue
=
data
[
offset
+
3
]
;
color
=
[
UIColor
colorWithRed
:
(
red
/
255.0f
)
green
:
(
green
/
255.0f
)
blue
:
(
blue
/
255.0f
)
alpha
:
(
alpha
/
255.0f
)
]
;
}
CGContextRelease
(
cgctx
)
;
if
(
data
)
{
free
(
data
)
;
}
return
color
;
}
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字符串反转
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第一种：
-
(
NSString *
)
reverseWordsInString
:
(
NSString *
)
str
{
NSMutableString *
newString
=
[
[
NSMutableString
alloc
]
initWithCapacity
:
str
.
length
]
;
for
(
NSInteger
i
=
str
.
length
-
1
;
i
>=
0
;
i
--
)
{
unichar
ch
=
[
str
characterAtIndex
:
i
]
;
[
newString
appendFormat
:
@
"%c"
,
ch
]
;
}
return
newString
;
}
//第二种：
-
(
NSString*
)
reverseWordsInString
:
(
NSString*
)
str
{
NSMutableString *
reverString
=
[
NSMutableString
stringWithCapacity
:
str
.
length
]
;
[
str
enumerateSubstringsInRange
:
NSMakeRange
(
0
,
str
.
length
)
options
:
NSStringEnumerationReverse
|
NSStringEnumerationByComposedCharacterSequences
usingBlock
:
^
(
NSString *
substring
,
NSRange
substringRange
,
NSRange
enclosingRange
,
BOOL
*
stop
)
{
[
reverString
appendString
:
substring
]
;
}
]
;
return
reverString
;
}
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禁止锁屏，
默认情况下，当设备一段时间没有触控动作时，iOS会锁住屏幕。但有一些应用是不需要锁屏的，比如视频播放器。
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[
UIApplication
sharedApplication
]
.
idleTimerDisabled
=
YES
;
或
[
[
UIApplication
sharedApplication
]
setIdleTimerDisabled
:
YES
]
;
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模态推出透明界面
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UIViewController *
vc
=
[
[
UIViewController
alloc
]
init
]
;
UINavigationController *
na
=
[
[
UINavigationController
alloc
]
initWithRootViewController
:
vc
]
;
if
(
[
[
[
UIDevice
currentDevice
]
systemVersion
]
floatValue
]
>=
8.0
)
{
na
.
modalPresentationStyle
=
UIModalPresentationOverCurrentContext
;
}
else
{
self
.
modalPresentationStyle
=
UIModalPresentationCurrentContext
;
}
[
self
presentViewController
:
na
animated
:
YES
completion
:
nil
]
;
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Xcode调试不显示内存占用
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editSCheme
里面有个选项叫叫做
enable
zoombie
Objects
取消选中
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显示隐藏文件
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//显示
defaults
write
com
.
apple
.
finder
AppleShowAllFiles
-
bool
true
killall
Finder
//隐藏
defaults
write
com
.
apple
.
finder
AppleShowAllFiles
-
bool
false
killall
Finder
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字符串按多个符号分割
iOS跳转到App Store下载应用评分
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[
[
UIApplication
sharedApplication
]
openURL
:
[
NSURL
URLWithString
:
@
"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"
]
]
;
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iOS 获取汉字的拼音
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+
(
NSString *
)
transform
:
(
NSString *
)
chinese
{
//将NSString装换成NSMutableString
NSMutableString *
pinyin
=
[
chinese
mutableCopy
]
;
//将汉字转换为拼音(带音标)
CFStringTransform
(
(
__bridge
CFMutableStringRef
)
pinyin
,
NULL
,
kCFStringTransformMandarinLatin
,
NO
)
;
NSLog
(
@
"%@"
,
pinyin
)
;
//去掉拼音的音标
CFStringTransform
(
(
__bridge
CFMutableStringRef
)
pinyin
,
NULL
,
kCFStringTransformStripCombiningMarks
,
NO
)
;
NSLog
(
@
"%@"
,
pinyin
)
;
//返回最近结果
return
pinyin
;
}
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手动更改iOS状态栏的颜色
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-
(
void
)
setStatusBarBackgroundColor
:
(
UIColor *
)
color
{
UIView *
statusBar
=
[
[
[
UIApplication
sharedApplication
]
valueForKey
:
@
"statusBarWindow"
]
valueForKey
:
@
"statusBar"
]
;
if
(
[
statusBar
respondsToSelector
:
@
selector
(
setBackgroundColor
:
)
]
)
{
statusBar
.
backgroundColor
=
color
;
}
}
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判断当前ViewController是push还是present的方式显示的
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NSArray *
viewcontrollers
=
self
.
navigationController
.
viewControllers
;
if
(
viewcontrollers
.
count
>
1
)
{
if
(
[
viewcontrollers
objectAtIndex
:
viewcontrollers
.
count
-
1
]
==
self
)
{
//push方式
[
self
.
navigationController
popViewControllerAnimated
:
YES
]
;
}
}
else
{
//present方式
[
self
dismissViewControllerAnimated
:
YES
completion
:
nil
]
;
}
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获取实际使用的LaunchImage图片
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-
(
NSString *
)
getLaunchImageName
{
CGSize
viewSize
=
self
.
window
.
bounds
.
size
;
// 竖屏
NSString *
viewOrientation
=
@
"Portrait"
;
NSString *
launchImageName
=
nil
;
NSArray*
imagesDict
=
[
[
[
NSBundle
mainBundle
]
infoDictionary
]
valueForKey
:
@
"UILaunchImages"
]
;
for
(
NSDictionary*
dict
in
imagesDict
)
{
CGSize
imageSize
=
CGSizeFromString
(
dict
[
@
"UILaunchImageSize"
]
)
;
if
(
CGSizeEqualToSize
(
imageSize
,
viewSize
)
&&
[
viewOrientation
isEqualToString
:
dict
[
@
"UILaunchImageOrientation"
]
]
)
{
launchImageName
=
dict
[
@
"UILaunchImageName"
]
;
}
}
return
launchImageName
;
}
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iOS在当前屏幕获取第一响应
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UIWindow *
keyWindow
=
[
[
UIApplication
sharedApplication
]
keyWindow
]
;
UIView *
firstResponder
=
[
keyWindow
performSelector
:
@
selector
(
firstResponder
)
]
;
|
判断对象是否遵循了某协议
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if
(
[
self
.
selectedController
conformsToProtocol
:
@
protocol
(
RefreshPtotocol
)
]
)
{
[
self
.
selectedController
performSelector
:
@
selector
(
onTriggerRefresh
)
]
;
}
|
判断view是不是指定视图的子视图
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BOOL
isView
=
[
textView
isDescendantOfView
:
self
.
view
]
;
|
NSArray 快速求总和 最大值 最小值 和 平均值
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NSArray *
array
=
[
NSArray
arrayWithObjects
:
@
"2.0"
,
@
"2.3"
,
@
"3.0"
,
@
"4.0"
,
@
"10"
,
nil
]
;
CGFloat
sum
=
[
[
array
valueForKeyPath
:
@
"@sum.floatValue"
]
floatValue
]
;
CGFloat
avg
=
[
[
array
valueForKeyPath
:
@
"@avg.floatValue"
]
floatValue
]
;
CGFloat
max
=
[
[
array
valueForKeyPath
:
@
"@max.floatValue"
]
floatValue
]
;
CGFloat
min
=
[
[
array
valueForKeyPath
:
@
"@min.floatValue"
]
floatValue
]
;
NSLog
(
@
"%f\n%f\n%f\n%f"
,
sum
,
avg
,
max
,
min
)
;
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修改UITextField中Placeholder的文字颜色
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[
textField
setValue
:
[
UIColor
redColor
]
forKeyPath
:
@
"_placeholderLabel.textColor"
]
;
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关于NSDateFormatter的格式
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G
:
公元时代，例如
AD公元
yy
:
年的后
2位
yyyy
:
完整年
MM
:
月，显示为
1
-
12
MMM
:
月，显示为英文月份简写
,如
Jan
MMMM
:
月，显示为英文月份全称，如
Janualy
dd
:
日，
2位数表示，如
02
d
:
日，
1
-
2位显示，如
2
EEE
:
简写星期几，如
Sun
EEEE
:
全写星期几，如
Sunday
aa
:
上下午，
AM
/
PM
H
:
时，
24小时制，
0
-
23
K：时，
12小时制，
0
-
11
m
:
分，
1
-
2位
mm
:
分，
2位
s
:
秒，
1
-
2位
ss
:
秒，
2位
S
:
毫秒
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获取一个类的所有子类
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+
(
NSArray *
)
allSubclasses
{
Class
myClass
=
[
self
class
]
;
NSMutableArray *
mySubclasses
=
[
NSMutableArray
array
]
;
unsigned
int
numOfClasses
;
Class
*
classes
=
objc_copyClassList
(
&
numOfClasses
;
)
;
for
(
unsigned
int
ci
=
0
;
ci
|
监测IOS设备是否设置了代理，需要CFNetwork.framework
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NSDictionary *
proxySettings
=
(
__bridge
NSDictionary *
)
(
CFNetworkCopySystemProxySettings
(
)
)
;
NSArray *
proxies
=
(
__bridge
NSArray *
)
(
CFNetworkCopyProxiesForURL
(
(
__bridge
CFURLRef
_Nonnull
)
(
[
NSURL
URLWithString
:
@
"http://www.baidu.com"
]
)
,
(
__bridge
CFDictionaryRef
_Nonnull
)
(
proxySettings
)
)
)
;
NSLog
(
@
"\n%@"
,
proxies
)
;
NSDictionary *
settings
=
proxies
[
0
]
;
NSLog
(
@
"%@"
,
[
settings
objectForKey
:
(
NSString *
)
kCFProxyHostNameKey
]
)
;
NSLog
(
@
"%@"
,
[
settings
objectForKey
:
(
NSString *
)
kCFProxyPortNumberKey
]
)
;
NSLog
(
@
"%@"
,
[
settings
objectForKey
:
(
NSString *
)
kCFProxyTypeKey
]
)
;
if
(
[
[
settings
objectForKey
:
(
NSString *
)
kCFProxyTypeKey
]
isEqualToString
:
@
"kCFProxyTypeNone"
]
)
{
NSLog
(
@
"没代理"
)
;
}
else
{
NSLog
(
@
"设置了代理"
)
;
}
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阿拉伯数字转中文格式
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+
(
NSString *
)
translation
:
(
NSString *
)
arebic
{
NSString *
str
=
arebic
;
NSArray *
arabic_numerals
=
@
[
@
"1"
,
@
"2"
,
@
"3"
,
@
"4"
,
@
"5"
,
@
"6"
,
@
"7"
,
@
"8"
,
@
"9"
,
@
"0"
]
;
NSArray *
chinese_numerals
=
@
[
@
"一"
,
@
"二"
,
@
"三"
,
@
"四"
,
@
"五"
,
@
"六"
,
@
"七"
,
@
"八"
,
@
"九"
,
@
"零"
]
;
NSArray *
digits
=
@
[
@
"个"
,
@
"十"
,
@
"百"
,
@
"千"
,
@
"万"
,
@
"十"
,
@
"百"
,
@
"千"
,
@
"亿"
,
@
"十"
,
@
"百"
,
@
"千"
,
@
"兆"
]
;
NSDictionary *
dictionary
=
[
NSDictionary
dictionaryWithObjects
:
chinese_numerals
forKeys
:
arabic_numerals
]
;
NSMutableArray *
sums
=
[
NSMutableArray
array
]
;
for
(
int
i
=
0
;
i
|
Base64编码与NSString对象或NSData对象的转换
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// Create NSData object
NSData *
nsdata
=
[
@
"iOS Developer Tips encoded in Base64"
dataUsingEncoding
:
NSUTF8StringEncoding
]
;
// Get NSString from NSData object in Base64
NSString *
base64Encoded
=
[
nsdata
base64EncodedStringWithOptions
:
0
]
;
// Print the Base64 encoded string
NSLog
(
@
"Encoded: %@"
,
base64Encoded
)
;
// Let's go the other way...
// NSData from the Base64 encoded str
NSData *
nsdataFromBase64String
=
[
[
NSData
alloc
]
initWithBase64EncodedString
:
base64Encoded
options
:
0
]
;
// Decoded NSString from the NSData
NSString *
base64Decoded
=
[
[
NSString
alloc
]
initWithData
:
nsdataFromBase64String
encoding
:
NSUTF8StringEncoding
]
;
NSLog
(
@
"Decoded: %@"
,
base64Decoded
)
;
|
取消UICollectionView的隐式动画
UICollectionView在reloadItems的时候，默认会附加一个隐式的fade动画，有时候很讨厌，尤其是当你的cell是复合cell的情况下(比如cell使用到了UIStackView)。
下面几种方法都可以帮你去除这些动画
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
//方法一
[
UIView
performWithoutAnimation
:
^
{
[
collectionView
reloadItemsAtIndexPaths
:
@
[
[
NSIndexPath
indexPathForItem
:
index
inSection
:
0
]
]
]
;
}
]
;
//方法二
[
UIView
animateWithDuration
:
0
animations
:
^
{
[
collectionView
performBatchUpdates
:
^
{
[
collectionView
reloadItemsAtIndexPaths
:
@
[
[
NSIndexPath
indexPathForItem
:
index
inSection
:
0
]
]
]
;
}
completion
:
nil
]
;
}
]
;
//方法三
[
UIView
setAnimationsEnabled
:
NO
]
;
[
self
.
trackPanel
performBatchUpdates
:
^
{
[
collectionView
reloadItemsAtIndexPaths
:
@
[
[
NSIndexPath
indexPathForItem
:
index
inSection
:
0
]
]
]
;
}
completion
:
^
(
BOOL
finished
)
{
[
UIView
setAnimationsEnabled
:
YES
]
;
}
]
;
|
让Xcode的控制台支持LLDB类型的打印
|
1
2
3
4
|
打开终端输入三条命令
:
touch
~
/
.
lldbinit
echo
display
@
import
UIKit
>>
~
/
.
lldbinit
echo
target
stop
-
hook
add
-
o
\"
target
stop
-
hook
disable
\"
>>
~
/
.
lldbinit
|
CocoaPods pod install/pod update更新慢的问题
|
1
2
3
|
pod
install
--
verbose
--
no
-
repo
-
update
pod
update
--
verbose
--
no
-
repo
-
update
如果不加后面的参数，默认会升级
CocoaPods的
spec仓库，加一个参数可以省略这一步，然后速度就会提升不少
|
UIImage 占用内存大小
|
1
2
|
UIImage *
image
=
[
UIImage
imageNamed
:
@
"aa"
]
;
NSUInteger
size
=
CGImageGetHeight
(
image
.
CGImage
)
*
CGImageGetBytesPerRow
(
image
.
CGImage
)
;
|
GCD timer定时器
|
1
2
3
4
5
6
7
8
9
10
11
|
dispatch_queue_t
queue
=
dispatch_get_global_queue
(
DISPATCH_QUEUE_PRIORITY_DEFAULT
,
0
)
;
dispatch_source_t
timer
=
dispatch_source_create
(
DISPATCH_SOURCE_TYPE_TIMER
,
0
,
0
,
queue
)
;
dispatch_source_set_timer
(
timer
,
dispatch_walltime
(
NULL
,
0
)
,
1.0
*
NSEC_PER_SEC
,
0
)
;
//每秒执行
dispatch_source_set_event_handler
(
timer
,
^
{
//@"倒计时结束，关闭"
dispatch_source_cancel
(
timer
)
;
dispatch_async
(
dispatch_get_main_queue
(
)
,
^
{
}
)
;
}
)
;
dispatch_resume
(
timer
)
;
|
图片上绘制文字 写一个UIImage的category
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
-
(
UIImage *
)
imageWithTitle
:
(
NSString *
)
title
fontSize
:
(
CGFloat
)
fontSize
{
//画布大小
CGSize
size
=
CGSizeMake
(
self
.
size
.
width
,
self
.
size
.
height
)
;
//创建一个基于位图的上下文
UIGraphicsBeginImageContextWithOptions
(
size
,
NO
,
0.0
)
;
//opaque:NO scale:0.0
[
self
drawAtPoint
:
CGPointMake
(
0.0
,
0.0
)
]
;
//文字居中显示在画布上
NSMutableParagraphStyle*
paragraphStyle
=
[
[
NSParagraphStyle
defaultParagraphStyle
]
mutableCopy
]
;
paragraphStyle
.
lineBreakMode
=
NSLineBreakByCharWrapping
;
paragraphStyle
.
alignment
=
NSTextAlignmentCenter
;
//文字居中
//计算文字所占的size,文字居中显示在画布上
CGSize
sizeText
=
[
title
boundingRectWithSize
:
self
.
size
options
:
NSStringDrawingUsesLineFragmentOrigin
attributes
:
@
{
NSFontAttributeName
:
[
UIFont
systemFontOfSize
:
fontSize
]
}
context
:
nil
]
.
size
;
CGFloat
width
=
self
.
size
.
width
;
CGFloat
height
=
self
.
size
.
height
;
CGRect
rect
=
CGRectMake
(
(
width
-
sizeText
.
width
)
/
2
,
(
height
-
sizeText
.
height
)
/
2
,
sizeText
.
width
,
sizeText
.
height
)
;
//绘制文字
[
title
drawInRect
:
rect
withAttributes
:
@
{
NSFontAttributeName
:
[
UIFont
systemFontOfSize
:
fontSize
]
,
NSForegroundColorAttributeName
:
[
UIColor
whiteColor
]
,
NSParagraphStyleAttributeName
:
paragraphStyle
}
]
;
//返回绘制的新图形
UIImage *
newImage
=
UIGraphicsGetImageFromCurrentImageContext
(
)
;
UIGraphicsEndImageContext
(
)
;
return
newImage
;
}
|
查找一个视图的所有子视图
|
1
2
3
4
5
6
7
8
9
10
11
12
13
|
-
(
NSMutableArray *
)
allSubViewsForView
:
(
UIView *
)
view
{
NSMutableArray *
array
=
[
NSMutableArray
arrayWithCapacity
:
0
]
;
for
(
UIView *
subView
in
view
.
subviews
)
{
[
array
addObject
:
subView
]
;
if
(
subView
.
subviews
.
count
>
0
)
{
[
array
addObjectsFromArray
:
[
self
allSubViewsForView
:
subView
]
]
;
}
}
return
array
;
}
|
计算文件大小
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
//文件大小
-
(
long
long
)
fileSizeAtPath
:
(
NSString *
)
path
{
NSFileManager *
fileManager
=
[
NSFileManager
defaultManager
]
;
if
(
[
fileManager
fileExistsAtPath
:
path
]
)
{
long
long
size
=
[
fileManager
attributesOfItemAtPath
:
path
error
:
nil
]
.
fileSize
;
return
size
;
}
return
0
;
}
//文件夹大小
-
(
long
long
)
folderSizeAtPath
:
(
NSString *
)
path
{
NSFileManager *
fileManager
=
[
NSFileManager
defaultManager
]
;
long
long
folderSize
=
0
;
if
(
[
fileManager
fileExistsAtPath
:
path
]
)
{
NSArray *
childerFiles
=
[
fileManager
subpathsAtPath
:
path
]
;
for
(
NSString *
fileName
in
childerFiles
)
{
NSString *
fileAbsolutePath
=
[
path
stringByAppendingPathComponent
:
fileName
]
;
if
(
[
fileManager
fileExistsAtPath
:
fileAbsolutePath
]
)
{
long
long
size
=
[
fileManager
attributesOfItemAtPath
:
fileAbsolutePath
error
:
nil
]
.
fileSize
;
folderSize
+=
size
;
}
}
}
return
folderSize
;
}
|
UIView设置部分圆角
你是不是也遇到过这样的问题，一个button或者label，只要右边的两个角圆角，或者只要一个圆角。该怎么办呢。这就需要图层蒙版来帮助我们了
|
1
2
3
4
5
6
7
8
|
CGRect
rect
=
view
.
bounds
;
CGSize
radio
=
CGSizeMake
(
30
,
30
)
;
//圆角尺寸
UIRectCorner
corner
=
UIRectCornerTopLeft
|
UIRectCornerTopRight
;
//这只圆角位置
UIBezierPath *
path
=
[
UIBezierPath
bezierPathWithRoundedRect
:
rect
byRoundingCorners
:
corner
cornerRadii
:
radio
]
;
CAShapeLayer *
masklayer
=
[
[
CAShapeLayer
alloc
]
init
]
;
//创建shapelayer
masklayer
.
frame
=
view
.
bounds
;
masklayer
.
path
=
path
.
CGPath
;
//设置路径
view
.
layer
.
mask
=
masklayer
;
|
取上整与取下整
|
1
2
3
4
5
6
7
8
9
10
|
floor
(
x
)
,有时候也写做
Floor
(
x
)，其功能是“下取整”，即取不大于
x的最大整数
例如：
x
=
3.14，
floor
(
x
)
=
3
y
=
9.99999，
floor
(
y
)
=
9
与
floor函数对应的是
ceil函数，即上取整函数。
ceil函数的作用是求不小于给定实数的最小整数。
ceil
(
2
)
=
ceil
(
1.2
)
=
cei
(
1.5
)
=
2.00
floor函数与
ceil函数的返回值均为
double型
|
计算字符串字符长度，一个汉字算两个字符
|
1
2
3
4
5
6
|
//方法一：
-
(
int
)
convertToInt
:
(
NSString*
)
strtemp
{
int
strlength
=
0
;
char
*
p
=
(
char
*
)
[
strtemp
cStringUsingEncoding
:
NSUnicodeStringEncoding
]
;
for
(
int
i
=
0
;
i
|
给UIView设置图片
|
1
2
3
|
UIImage *
image
=
[
UIImage
imageNamed
:
@
"image"
]
;
self
.
MYView
.
layer
.
contents
=
(
__bridge
id
_Nullable
)
(
image
.
CGImage
)
;
self
.
MYView
.
layer
.
contentsRect
=
CGRectMake
(
0
,
0
,
0.5
,
0.5
)
;
|
防止scrollView手势覆盖侧滑手势
|
1
|
[
scrollView
.
panGestureRecognizerrequireGestureRecognizerToFail
:
self
.
navigationController
.
interactivePopGestureRecognizer
]
;
|
去掉导航栏返回的back标题
|
1
|
[
[
UIBarButtonItemappearance
]
setBackButtonTitlePositionAdjustment
:
UIOffsetMake
(
0
,
-
60
)
forBarMetrics
:
UIBarMetricsDefault
]
;
|
字符串中是否含有中文
|
1
2
3
|
+
(
BOOL
)
checkIsChinese
:
(
NSString *
)
string
{
for
(
int
i
=
0
;
i
|
dispatch_group的使用
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
dispatch_group_t
dispatchGroup
=
dispatch_group_create
(
)
;
dispatch_group_enter
(
dispatchGroup
)
;
dispatch_after
(
dispatch_time
(
DISPATCH_TIME_NOW
,
(
int64_t
)
(
1
*
NSEC_PER_SEC
)
)
,
dispatch_get_main_queue
(
)
,
^
{
NSLog
(
@
"第一个请求完成"
)
;
dispatch_group_leave
(
dispatchGroup
)
;
}
)
;
dispatch_group_enter
(
dispatchGroup
)
;
dispatch_after
(
dispatch_time
(
DISPATCH_TIME_NOW
,
(
int64_t
)
(
10
*
NSEC_PER_SEC
)
)
,
dispatch_get_main_queue
(
)
,
^
{
NSLog
(
@
"第二个请求完成"
)
;
dispatch_group_leave
(
dispatchGroup
)
;
}
)
;
dispatch_group_notify
(
dispatchGroup
,
dispatch_get_main_queue
(
)
,
^
(
)
{
NSLog
(
@
"请求完成"
)
;
}
)
;
|
UITextField每四位加一个空格,实现代理
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
-
(
BOOL
)
textField
:
(
UITextField *
)
textField
shouldChangeCharactersInRange
:
(
NSRange
)
range
replacementString
:
(
NSString *
)
string
{
// 四位加一个空格
if
(
[
string
isEqualToString
:
@
""
]
)
{
// 删除字符
if
(
(
textField
.
text
.
length
-
2
)
%
5
==
0
)
{
textField
.
text
=
[
textField
.
text
substringToIndex
:
textField
.
text
.
length
-
1
]
;
}
return
YES
;
}
else
{
if
(
textField
.
text
.
length
%
5
==
0
)
{
textField
.
text
=
[
NSString
stringWithFormat
:
@
"%@ "
,
textField
.
text
]
;
}
}
return
YES
;
}
|
获取私有属性和成员变量 #import
|
1
2
3
4
5
6
7
|
//获取私有属性 比如设置UIDatePicker的字体颜色
-
(
void
)
setTextColor
{
//获取所有的属性，去查看有没有对应的属性
unsigned
int
count
=
0
;
objc_property_t *
propertys
=
class_copyPropertyList
(
[
UIDatePicker
class
]
,
&
count
)
;
for
(
int
i
=
0
;
i
|
|
1
2
3
4
|
//获得成员变量 比如修改UIAlertAction的按钮字体颜色
unsigned
int
count
=
0
;
Ivar *
ivars
=
class_copyIvarList
(
[
UIAlertAction
class
]
,
&
count
)
;
for
(
int
i
=
0
;
i
|
获取手机安装的应用
|
1
2
3
4
5
6
7
8
9
10
|
Class
c
=
NSClassFromString
(
@
"LSApplicationWorkspace"
)
;
id
s
=
[
(
id
)
c
performSelector
:
NSSelectorFromString
(
@
"defaultWorkspace"
)
]
;
NSArray *
array
=
[
s
performSelector
:
NSSelectorFromString
(
@
"allInstalledApplications"
)
]
;
for
(
id
item
in
array
)
{
NSLog
(
@
"%@"
,
[
item
performSelector
:
NSSelectorFromString
(
@
"applicationIdentifier"
)
]
)
;
//NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleIdentifier")]);
NSLog
(
@
"%@"
,
[
item
performSelector
:
NSSelectorFromString
(
@
"bundleVersion"
)
]
)
;
NSLog
(
@
"%@"
,
[
item
performSelector
:
NSSelectorFromString
(
@
"shortVersionString"
)
]
)
;
}
|
判断两个日期是否在同一周 写在NSDate的category里面
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
-
(
BOOL
)
isSameDateWithDate
:
(
NSDate *
)
date
{
//日期间隔大于七天之间返回NO
if
(
fabs
(
[
self
timeIntervalSinceDate
:
date
]
)
>=
7
*
24
*
3600
)
{
return
NO
;
}
NSCalendar *
calender
=
[
NSCalendar
currentCalendar
]
;
calender
.
firstWeekday
=
2
;
//设置每周第一天从周一开始
//计算两个日期分别为这年第几周
NSUInteger
countSelf
=
[
calender
ordinalityOfUnit
:
NSCalendarUnitWeekday
inUnit
:
NSCalendarUnitYear
forDate
:
self
]
;
NSUInteger
countDate
=
[
calender
ordinalityOfUnit
:
NSCalendarUnitWeekday
inUnit
:
NSCalendarUnitYear
forDate
:
date
]
;
//相等就在同一周，不相等就不在同一周
return
countSelf
==
countDate
;
}
|
应用内打开系统设置界面
|
1
2
3
|
//iOS8之后
[
[
UIApplication
sharedApplication
]
openURL
:
[
NSURL
URLWithString
:
UIApplicationOpenSettingsURLString
]
]
;
//如果App没有添加权限，显示的是设定界面。如果App有添加权限（例如通知），显示的是App的设定界面。
|
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
//iOS8之前
//先添加一个url type如下图，在代码中调用如下代码,即可跳转到设置页面的对应项
[
[
UIApplication
sharedApplication
]
openURL
:
[
NSURL
URLWithString
:
@
"prefs:root=WIFI"
]
]
;
可选值如下：
About
—
prefs
:
root
=
General
&
path
=
About
Accessibility
—
prefs
:
root
=
General
&
path
=
ACCESSIBILITY
Airplane
Mode
On
—
prefs
:
root
=
AIRPLANE_MODE
Auto
-
Lock
—
prefs
:
root
=
General
&
path
=
AUTOLOCK
Brightness
—
prefs
:
root
=
Brightness
Bluetooth
—
prefs
:
root
=
General
&
path
=
Bluetooth
Date
&
Time
—
prefs
:
root
=
General
&
path
=
DATE_AND_TIME
FaceTime
—
prefs
:
root
=
FACETIME
General
—
prefs
:
root
=
General
Keyboard
—
prefs
:
root
=
General
&
path
=
Keyboard
iCloud
—
prefs
:
root
=
CASTLE
iCloud
Storage
&
Backup
—
prefs
:
root
=
CASTLE
&
path
=
STORAGE_AND_BACKUP
International
—
prefs
:
root
=
General
&
path
=
INTERNATIONAL
Location
Services
—
prefs
:
root
=
LOCATION_SERVICES
Music
—
prefs
:
root
=
MUSIC
Music
Equalizer
—
prefs
:
root
=
MUSIC
&
path
=
EQ
Music
Volume
Limit
—
prefs
:
root
=
MUSIC
&
path
=
VolumeLimit
Network
—
prefs
:
root
=
General
&
path
=
Network
Nike
+
iPod
—
prefs
:
root
=
NIKE_PLUS_IPOD
Notes
—
prefs
:
root
=
NOTES
Notification
—
prefs
:
root
=
NOTIFICATI*
*
*
*
*
_ID
Phone
—
prefs
:
root
=
Phone
Photos
—
prefs
:
root
=
Photos
Profile
—
prefs
:
root
=
General
&
path
=
ManagedConfigurationList
Reset
—
prefs
:
root
=
General
&
path
=
Reset
Safari
—
prefs
:
root
=
Safari
Siri
—
prefs
:
root
=
General
&
path
=
Assistant
Sounds
—
prefs
:
root
=
Sounds
Software
Update
—
prefs
:
root
=
General
&
path
=
SOFTWARE_UPDATE_LINK
Store
—
prefs
:
root
=
STORE
Twitter
—
prefs
:
root
=
TWITTER
Usage
—
prefs
:
root
=
General
&
path
=
USAGE
VPN
—
prefs
:
root
=
General
&
path
=
Network
/
VPN
Wallpaper
—
prefs
:
root
=
Wallpaper
Wi
-
Fi
—
prefs
:
root
=
WIFI
|
屏蔽触发事件，2秒后取消屏蔽
|
1
2
3
4
|
[
[
UIApplication
sharedApplication
]
beginIgnoringInteractionEvents
]
;
dispatch_after
(
dispatch_time
(
DISPATCH_TIME_NOW
,
(
int64_t
)
(
2
*
NSEC_PER_SEC
)
)
,
dispatch_get_main_queue
(
)
,
^
{
[
[
UIApplication
sharedApplication
]
endIgnoringInteractionEvents
]
}
)
;
|
动画暂停再开始
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
-
(
void
)
pauseLayer
:
(
CALayer *
)
layer
{
CFTimeInterval
pausedTime
=
[
layer
convertTime
:
CACurrentMediaTime
(
)
fromLayer
:
nil
]
;
layer
.
speed
=
0.0
;
layer
.
timeOffset
=
pausedTime
;
}
-
(
void
)
resumeLayer
:
(
CALayer *
)
layer
{
CFTimeInterval
pausedTime
=
[
layer
timeOffset
]
;
layer
.
speed
=
1.0
;
layer
.
timeOffset
=
0.0
;
layer
.
beginTime
=
0.0
;
CFTimeInterval
timeSincePause
=
[
layer
convertTime
:
CACurrentMediaTime
(
)
fromLayer
:
nil
]
-
pausedTime
;
layer
.
beginTime
=
timeSincePause
;
}
|
fillRule原理
iOS中数字的格式化
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
|
//通过NSNumberFormatter，同样可以设置NSNumber输出的格式。例如如下代码：
NSNumberFormatter *
formatter
=
[
[
NSNumberFormatter
alloc
]
init
]
;
formatter
.
numberStyle
=
NSNumberFormatterDecimalStyle
;
NSString *
string
=
[
formatter
stringFromNumber
:
[
NSNumber
numberWithInt
:
123456789
]
]
;
NSLog
(
@
"Formatted number string:%@"
,
string
)
;
//输出结果为：[1223:403] Formatted number string:123,456,789
//其中NSNumberFormatter类有个属性numberStyle，它是一个枚举型，设置不同的值可以输出不同的数字格式。该枚举包括：
typedef
NS_ENUM
(
NSUInteger
,
NSNumberFormatterStyle
)
{
NSNumberFormatterNoStyle
=
kCFNumberFormatterNoStyle
,
NSNumberFormatterDecimalStyle
=
kCFNumberFormatterDecimalStyle
,
NSNumberFormatterCurrencyStyle
=
kCFNumberFormatterCurrencyStyle
,
NSNumberFormatterPercentStyle
=
kCFNumberFormatterPercentStyle
,
NSNumberFormatterScientificStyle
=
kCFNumberFormatterScientificStyle
,
NSNumberFormatterSpellOutStyle
=
kCFNumberFormatterSpellOutStyle
}
;
//各个枚举对应输出数字格式的效果如下：其中第三项和最后一项的输出会根据系统设置的语言区域的不同而不同。
[
1243
:
403
]
Formatted
number
string
:
123456789
[
1243
:
403
]
Formatted
number
string
:
123
,
456
,
789
[
1243
:
403
]
Formatted
number
string
:￥
123
,
456
,
789.00
[
1243
:
403
]
Formatted
number
string
:
-
539
,
222
,
988
%
[
1243
:
403
]
Formatted
number
string
:
1.23456789E8
[
1243
:
403
]
Formatted
number
string
:一亿二千三百四十五万六千七百八十九
|
如何获取WebView所有的图片地址，
在网页加载完成时，通过js获取图片和添加点击的识别方式
|
1
2
3
4
5
6
7
8
9
|
//UIWebView
-
(
void
)
webViewDidFinishLoad
:
(
UIWebView *
)
webView
{
//这里是js，主要目的实现对url的获取
static
NSString *
const
jsGetImages
=
@"
function
getImages
(
)
{
\
var
objs
=
document
.
getElementsByTagName
(
\"
img
\"
)
;
\
var
imgScr
=
''
;
\
for
(
var
i
=
0
;
i
|
|
1
2
3
4
5
6
7
8
|
//WKWebView
-
(
void
)
webView
:
(
WKWebView *
)
webView
didFinishNavigation
:
(
null_unspecified
WKNavigation *
)
navigation
{
static
NSString *
const
jsGetImages
=
@"
function
getImages
(
)
{
\
var
objs
=
document
.
getElementsByTagName
(
\"
img
\"
)
;
\
var
imgScr
=
''
;
\
for
(
var
i
=
0
;
i
|
获取到webview的高度
|
1
|
CGFloat
height
=
[
[
self
.
webView
stringByEvaluatingJavaScriptFromString
:
@
"document.body.offsetHeight"
]
floatValue
]
;
|
navigationBar变为纯透明
|
1
2
3
4
5
6
7
8
|
//第一种方法
//导航栏纯透明
[
self
.
navigationBar
setBackgroundImage
:
[
UIImage
new
]
forBarMetrics
:
UIBarMetricsDefault
]
;
//去掉导航栏底部的黑线
self
.
navigationBar
.
shadowImage
=
[
UIImage
new
]
;
//第二种方法
[
[
self
.
navigationBar
subviews
]
objectAtIndex
:
0
]
.
alpha
=
0
;
|
tabBar同理
|
1
2
|
[
self
.
tabBar
setBackgroundImage
:
[
UIImage
new
]
]
;
self
.
tabBar
.
shadowImage
=
[
UIImage
new
]
;
|
navigationBar根据滑动距离的渐变色实现
|
1
2
3
4
5
6
7
|
//第一种
-
(
void
)
scrollViewDidScroll
:
(
UIScrollView *
)
scrollView
{
CGFloat
offsetToShow
=
200.0
;
//滑动多少就完全显示
CGFloat
alpha
=
1
-
(
offsetToShow
-
scrollView
.
contentOffset
.
y
)
/
offsetToShow
;
[
[
self
.
navigationController
.
navigationBar
subviews
]
objectAtIndex
:
0
]
.
alpha
=
alpha
;
}
|
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
|
//第二种
-
(
void
)
scrollViewDidScroll
:
(
UIScrollView *
)
scrollView
{
CGFloat
offsetToShow
=
200.0
;
CGFloat
alpha
=
1
-
(
offsetToShow
-
scrollView
.
contentOffset
.
y
)
/
offsetToShow
;
[
self
.
navigationController
.
navigationBar
setShadowImage
:
[
UIImage
new
]
]
;
[
self
.
navigationController
.
navigationBar
setBackgroundImage
:
[
self
imageWithColor
:
[
[
UIColor
orangeColor
]
colorWithAlphaComponent
:
alpha
]
]
forBarMetrics
:
UIBarMetricsDefault
]
;
}
//生成一张纯色的图片
-
(
UIImage *
)
imageWithColor
:
(
UIColor *
)
color
{
CGRect
rect
=
CGRectMake
(
0.0f
,
0.0f
,
1.0f
,
1.0f
)
;
UIGraphicsBeginImageContext
(
rect
.
size
)
;
CGContextRef
context
=
UIGraphicsGetCurrentContext
(
)
;
CGContextSetFillColorWithColor
(
context
,
[
color
CGColor
]
)
;
CGContextFillRect
(
context
,
rect
)
;
UIImage *
theImage
=
UIGraphicsGetImageFromCurrentImageContext
(
)
;
UIGraphicsEndImageContext
(
)
;
return
theImage
;
}
|
iOS 开发中一些相关的路径
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
模拟器的位置
:
/
Applications
/
Xcode
.
app
/
Contents
/
Developer
/
Platforms
/
iPhoneSimulator
.
platform
/
Developer
/
SDKs
文档安装位置
:
/
Applications
/
Xcode
.
app
/
Contents
/
Developer
/
Documentation
/
DocSets
插件保存路径
:
~
/
Library
/
ApplicationSupport
/
Developer
/
Shared
/
Xcode
/
Plug
-
ins
自定义代码段的保存路径
:
~
/
Library
/
Developer
/
Xcode
/
UserData
/
CodeSnippets
/
如果找不到
CodeSnippets文件夹，可以自己新建一个
CodeSnippets文件夹。
描述文件路径
~
/
Library
/
MobileDevice
/
Provisioning
Profiles
|
navigationItem的BarButtonItem如何紧靠屏幕右边界或者左边界？
一般情况下，右边的item会和屏幕右侧保持一段距离：
下面是通过添加一个负值宽度的固定间距的item来解决，也可以改变宽度实现不同的间隔：
|
1
2
3
4
5
6
7
8
|
UIImage *
img
=
[
[
UIImage
imageNamed
:
@
"icon_cog"
]
imageWithRenderingMode
:
UIImageRenderingModeAlwaysOriginal
]
;
//宽度为负数的固定间距的系统item
UIBarButtonItem *
rightNegativeSpacer
=
[
[
UIBarButtonItem
alloc
]
initWithBarButtonSystemItem
:
UIBarButtonSystemItemFixedSpace
target
:
nil
action
:
nil
]
;
[
rightNegativeSpacer
setWidth
:
-
15
]
;
UIBarButtonItem *
rightBtnItem1
=
[
[
UIBarButtonItem
alloc
]
initWithImage
:
img
style
:
UIBarButtonItemStylePlain
target
:
self
action
:
@
selector
(
rightButtonItemClicked
:
)
]
;
UIBarButtonItem *
rightBtnItem2
=
[
[
UIBarButtonItem
alloc
]
initWithImage
:
img
style
:
UIBarButtonItemStylePlain
target
:
self
action
:
@
selector
(
rightButtonItemClicked
:
)
]
;
self
.
navigationItem
.
rightBarButtonItems
=
@
[
rightNegativeSpacer
,
rightBtnItem1
,
rightBtnItem2
]
;
|
NSString进行URL编码和解码
|
1
2
3
4
5
6
7
|
NSString *
string
=
@
"http://abc.com?aaa=你好&bbb=tttee"
;
//编码 打印：http://abc.com?aaa=%E4%BD%A0%E5%A5%BD&bbb=tttee
string
=
[
string
stringByAddingPercentEncodingWithAllowedCharacters
:
[
NSCharacterSet
URLQueryAllowedCharacterSet
]
]
;
//解码 打印：http://abc.com?aaa=你好&bbb=tttee
string
=
[
string
stringByRemovingPercentEncoding
]
;
|
UIWebView设置User-Agent。
|
1
2
3
4
5
|
//设置
NSDictionary *
dic
=
@
{
@
"UserAgent"
:
@
"your UserAgent"
}
;
[
[
NSUserDefaults
standardUserDefaults
]
registerDefaults
:
dic
]
;
//获取
NSString *
agent
=
[
self
.
WebView
stringByEvaluatingJavaScriptFromString
:
@
"navigator.userAgent"
]
;
|
获取硬盘总容量与可用容量:
|
1
2
3
4
5
|
NSFileManager *
fileManager
=
[
NSFileManager
defaultManager
]
;
NSDictionary *
attributes
=
[
fileManager
attributesOfFileSystemForPath
:
NSHomeDirectory
(
)
error
:
nil
]
;
NSLog
(
@
"容量%.2fG"
,
[
attributes
[
NSFileSystemSize
]
doubleValue
]
/
(
powf
(
1024
,
3
)
)
)
;
NSLog
(
@
"可用%.2fG"
,
[
attributes
[
NSFileSystemFreeSize
]
doubleValue
]
/
powf
(
1024
,
3
)
)
;
|
获取UIColor的RGBA值
|
1
2
3
4
5
6
|
UIColor *
color
=
[
UIColor
colorWithRed
:
0.2
green
:
0.3
blue
:
0.9
alpha
:
1.0
]
;
const
CGFloat *
components
=
CGColorGetComponents
(
color
.
CGColor
)
;
NSLog
(
@
"Red: %.1f"
,
components
[
0
]
)
;
NSLog
(
@
"Green: %.1f"
,
components
[
1
]
)
;
NSLog
(
@
"Blue: %.1f"
,
components
[
2
]
)
;
NSLog
(
@
"Alpha: %.1f"
,
components
[
3
]
)
;
|
修改textField的placeholder的字体颜色、大小
|
1
2
|
[
self
.
textField
setValue
:
[
UIColor
redColor
]
forKeyPath
:
@
"_placeholderLabel.textColor"
]
;
[
self
.
textField
setValue
:
[
UIFont
boldSystemFontOfSize
:
16
]
forKeyPath
:
@
"_placeholderLabel.font"
]
;
|
AFN移除JSON中的NSNull
|
1
2
|
AFJSONResponseSerializer *
response
=
[
AFJSONResponseSerializer
serializer
]
;
response
.
removesKeysWithNullValues
=
YES
;
|
ceil()和floor()
ceil()功 能：返回大于或者等于指定表达式的最小整数floor()功 能：返回小于或者等于指定表达式的最大整数
UIWebView里面的图片自适应屏幕
在webView加载完的代理方法里面这样写：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
-
(
void
)
webViewDidFinishLoad
:
(
UIWebView
*
)
webView
{
NSString
*js
=
@"function imgAutoFit() { \
var imgs = document.getElementsByTagName('img'); \
for (var i = 0; i < imgs.length; ++i) { \
var img = imgs[i]; \
img.style.maxWidth = %f; \
} \
}"
;
js
=
[
NSString
stringWithFormat
:js
,
[
UIScreen
mainScreen
]
.
bounds
.
size
.
width
-
20
]
;
[
webView
stringByEvaluatingJavaScriptFromString
:js
]
;
[
webView
stringByEvaluatingJavaScriptFromString
:
@"imgAutoFit()"
]
;
}
|
持续更新中……。
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