UITextView

1、基本用法：显示文本信息（不可编辑）

    UITextView * textView = [[UITextView alloc] init];
    textView.frame = self.view.bounds;
    textView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
    textView.editable = NO;//默认可编辑，设置为不可编辑
    textView.textColor = [UIColor orangeColor];
    textView.backgroundColor = [UIColor lightGrayColor];
    textView.font = [UIFont systemFontOfSize:20];
    NSMutableString * str = [[NSMutableString alloc] init];
    for (int i = 0; i < 100; i++) {
        [str appendString:[NSString stringWithFormat:@"这是第%i行\n", i]];
    }
    textView.text = str;
    [self.view addSubview:textView];

如果文本太多，超出屏幕，则会有滚动条：

2、可编辑状态

    _textView.editable = YES;

当出现键盘时，会遮挡最下面部分：

对于这种，应该在键盘跳出和隐藏的时候，适当调整UITextView的尺寸，具体做法如下：

#import "ViewController.h"

@interface ViewController () <UITextViewDelegate>
{
    UITextView * _textView;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor whiteColor];
    
    
    _textView = [[UITextView alloc] init];
    _textView.frame = self.view.bounds;
    _textView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
    _textView.editable = YES;//设置是否可编辑
    _textView.textColor = [UIColor orangeColor];
    _textView.backgroundColor = [UIColor lightGrayColor];
    _textView.font = [UIFont systemFontOfSize:20];
    _textView.delegate = self;
    NSMutableString * str = [[NSMutableString alloc] init];
    for (int i = 0; i <= 100; i++) {
        [str appendString:[NSString stringWithFormat:@"这是第%i行\n", i]];
    }
    NSRange range = NSMakeRange(str.length - 2, 2);
    //去掉最后一行后面的\n，否则会空一行
    [str deleteCharactersInRange:range];
    
    _textView.text = str;
    [self.view addSubview:_textView];
    
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyBoardShow:) name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyBoardHide:) name:UIKeyboardDidHideNotification object:nil];
    
}


- (void) keyBoardShow:(NSNotification *) notification {
    NSDictionary* info = [notification userInfo];
    //kbSize即為鍵盤尺寸 (有width, height)
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;//得到鍵盤的高度
    NSLog(@"keyboard_height:%f",kbSize.height);
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.5];
    CGRect textViewFrame = _textView.frame;
    CGRect newTextViewFrame = CGRectMake(textViewFrame.origin.x, textViewFrame.origin.y, textViewFrame.size.width, textViewFrame.size.height - kbSize.height);
    _textView.frame = newTextViewFrame;
    [UIView commitAnimations];
}
- (void) keyBoardHide:(NSNotification *) notification {
    
}


- (void)textViewDidBeginEditing:(UITextView *)textView {
    //或者在此处改变UITextView的frame
}

3、

- (BOOL)hasText;

判断有无文本

设置文本对齐方式

@property(nonatomic) NSTextAlignment textAlignment;    // default is NSLeftTextAlignment

常见的有这三种：（居左，居中，居右）

    NSTextAlignmentLeft 
    NSTextAlignmentCenter 
    NSTextAlignmentRight

取得文本的选择范围：

- (void)textViewDidChangeSelection:(UITextView *)textView {
    //此函数实时监测文本的选择情况
    NSLog(@"%@", NSStringFromRange(textView.selectedRange));
}

2015-12-04 10:03:55.778 07-UITextView[1218:27730] {1, 8}

滚动位置控制：

    [_textView scrollRangeToVisible:NSMakeRange(1, 1)];

执行此代码后，将立即滚动到NSRange所包含的字符的位置

4、URL与电话号码的链接显示

typedef NS_OPTIONS(NSUInteger, UIDataDetectorTypes) {
    //自动检测电话号码
    UIDataDetectorTypePhoneNumber                              = 1 << 0,          // Phone number detection

    //自动检测超链接
    UIDataDetectorTypeLink                                     = 1 << 1,          // URL detection

    //自动检测地址
    UIDataDetectorTypeAddress NS_ENUM_AVAILABLE_IOS(4_0)       = 1 << 2,          // Street address detection

    //自动检测日期
    UIDataDetectorTypeCalendarEvent NS_ENUM_AVAILABLE_IOS(4_0) = 1 << 3,          // Event detection

    UIDataDetectorTypeNone          = 0,               // No detection at all
    
    //自动检测全部
    UIDataDetectorTypeAll           = NSUIntegerMax    // All types
};

首先：

_textView.editable = NO;

然后：

    _textView.dataDetectorTypes = UIDataDetectorTypeAll;

点击网址：

5、 UITextView状态监视：

@protocol UITextViewDelegate <NSObject, UIScrollViewDelegate>

@optional


//编辑开始前被调用，如果返回NO，编辑将不会开始
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView;

//编辑结束前被调用，如果返回NO，编辑将不会结束
- (BOOL)textViewShouldEndEditing:(UITextView *)textView;

//编辑开始后被调用（UITextView变为第一响应者时调用）
- (void)textViewDidBeginEditing:(UITextView *)textView;

//编辑结束后被调用（UITextView失去第一响应者时被调用）
- (void)textViewDidEndEditing:(UITextView *)textView;

//改变文本前被调用，range中是变化范围，text中是变化后的字符串，如果返回NO，变化将不会被响应
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;

//文本变更时被调用
- (void)textViewDidChange:(UITextView *)textView;

//游标移动，选择范围发生变化是被调用
- (void)textViewDidChangeSelection:(UITextView *)textView;

//点击网址时被调用
- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange NS_AVAILABLE_IOS(7_0);

- (BOOL)textView:(UITextView *)textView shouldInteractWithTextAttachment:(NSTextAttachment *)textAttachment inRange:(NSRange)characterRange NS_AVAILABLE_IOS(7_0);

@end

6、图文混排

    CGRect rect = CGRectMake(100, 100, 100, 100);
    
    UIView * view1 = [[UIView alloc] initWithFrame:rect];
    view1.backgroundColor = [UIColor redColor];
    [self.view addSubview:view1];
    //设置环绕的路径
    UIBezierPath * path = [UIBezierPath bezierPathWithRect:rect];
    
    _textView.textContainer.exclusionPaths = @[path];

红色区域可以放置图片，或者其他UIView