IOS 设置UIViewController为背景半透明浮层弹窗，查看富文本图片详情

使���场景：UIViewController1 打开 UIViewController2（背景半透明弹窗）

案例：打开富文本网页图片的url查看图片详情

WKWebView  WKNavigationDelegate代理方法设置js代码点击事件 

///注册添加图片标签点击js方法- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation{    ///js添加图片点击事件    NSString *jsClickImage =@"function registerImageClickAction(){var imgs=document.getElementsByTagName('img');var length=imgs.length;for(var i=0; i  
showPicDetail:()  方法打开浮窗：
 
-(void) showPicDetail:(NSString *)imgUrl{    ShowBigPicDetailViewController *vc = [[ShowBigPicDetailViewController alloc] init];    vc.imageUrl = imageUrl;    //设置全屏显示   关键语句，必须有    vc.modalPresentationStyle = UIModalPresentationOverCurrentContext;    [self presentViewController:vc animated:YES completion:nil];}
 
设置UIViewController2 背景半透明
 
- (void)viewDidLoad {    [super viewDidLoad];    //设置半透明背景    [self.view setBackgroundColor:[UIColor colorWithRed:0 green:0 blue:0 alpha:0.5f]];    ...}
 
关闭浮窗弹窗：
 
[self dismissViewControllerAnimated:YES completion:nil];