Iphone 开发常用代码-优快云博客

本文链接：https://blog.youkuaiyun.com/linwwwei/article/details/83971337

本文介绍了一系列iOS开发中的UI动画实现方法及Web视图与原生视图的交互技巧，包括如何定制数字键盘按钮、创建连续图片动画、加载网页图片，并通过JavaScript从Web视图中提取数据。

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1.更改cell选中的背景
    UIView *myview = [[UIView alloc] init];
    myview.frame = CGRectMake(0, 0, 320, 47);
    myview.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"0006.png"]];
    cell.selectedBackgroundView = myview;

2.在数字键盘上添加button：
//定义一个消息中心
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil]; //addObserver:注册一个观察员 name:消息名称
- (void)keyboardWillShow:(NSNotification *)note {
    // create custom button
    UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeCustom];
    doneButton.frame = CGRectMake(0, 163, 106, 53);
    [doneButton setImage:[UIImage imageNamed:@"5.png"] forState:UIControlStateNormal];
    [doneButton addTarget:self action:@selector(addRadixPoint) forControlEvents:UIControlEventTouchUpInside];

    // locate keyboard view
    UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];//返回应用程序window
    UIView* keyboard;
    for(int i=0; i<[tempWindow.subviews count]; i++) //遍历window上的所有subview
    {
        keyboard = [tempWindow.subviews objectAtIndex:i];
        // keyboard view found; add the custom button to it
        if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)
        [keyboard addSubview:doneButton];
    }
}

3.将一个空间放在视图之上

[scrollView insertSubview:searchButton aboveSubview:scrollView];

从本地加载图片
NSString *boundle = [[NSBundle mainBundle] resourcePath];
[web1 loadHTMLString:[NSString stringWithFormat:@"<img src='0001.png'/>"] baseURL:[NSURL fileURLWithPath:boundle]];

4.从网页加载图片并让图片在规定长宽中缩小
[cell.img loadHTMLString:[NSString stringWithFormat:@"<html><body><img src='%@' height='90px' width='90px'></body></html>",goodsInfo.GoodsImg] baseURL:nil];

5.将网页加载到webview上通过javascript获取里面的数据，如果只是发送了一个连接请求获取到源码以后可以用正则表达式进行获取数据
NSString *javaScript1 = @"document.getElementsByName('.u').item(0).value";
NSString *javaScript2 = @"document.getElementsByName('.challenge').item(0).value";
NSString *strResult1 = [NSString stringWithString:[theWebView stringByEvaluatingJavaScriptFromString:javaScript1]];
NSString *strResult2 = [NSString stringWithString:[theWebView stringByEvaluatingJavaScriptFromString:javaScript2]];

6.用NSString怎么把UTF8转换成unicode
utf8Str //
NSString *unicodeStr = [NSString stringWithCString:[utf8Str UTF8String] encoding:NSUnicodeStringEncoding];

7.View自己调用自己的方法:
[self performSelector:@selector(loginToNext) withObject:nil afterDelay:2];//黄色段为方法名,和延迟几秒执行.

8.WebView:

CGRect webFrame = CGRectMake(0.0, 0.0, 320.0, 460.0);
UIWebView *webView = [[UIWebView alloc] initWithFrame:webFrame];
[webView setBackgroundColor:[UIColor whiteColor]];
NSString *urlAddress = @"http://www.google.com";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:requestObj];
[self addSubview:webView];
[webView release];

9.显示网络活动状态指示符

这是在iPhone左上部的状态栏显示的转动的图标指示有背景发生网络的活动。

UIApplication* app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;

10.动画:一个接一个地显示一系列的图象

NSArray *myImages = [NSArray arrayWithObjects: [UIImage imageNamed:@"myImage1.png"], [UIImage imageNamed:@"myImage2.png"], [UIImage imageNamed:@"myImage3.png"], [UIImage imageNamed:@"myImage4.gif"], nil];
UIImageView *myAnimatedView = [UIImageView alloc];
[myAnimatedView initWithFrame:[self bounds]];
myAnimatedView.animationImages = myImages; //animationImages属性返回一个存放动画图片的数组
myAnimatedView.animationDuration = 0.25; //浏览整个图片一次所用的时间
myAnimatedView.animationRepeatCount = 0; // 0 = loops forever 动画重复次数
[myAnimatedView startAnimating];
[self addSubview:myAnimatedView];
[myAnimatedView release];