iOS 点击按钮截屏

@interface CaptureViewController ()

@property (nonatomic, strong) UIImageView *backgrounView; //控制器背景

@property (nonatomic, strong) UIView *captureView; //整个半透明图层

@property (nonatomic, strong) UIView *alertview; // 图层中间的view

@property (nonatomic, strong) UIImageView *captureImageView; //截屏后展示imageView

@property (nonatomic, strong) UIImage *captureImage; //截屏图片

@end

- (void)viewDidLoad {

[super viewDidLoad];

self.title = @"截屏";

[self initAllViews];

}

- (void)initAllViews { //设置背景图片

self.backgrounView = [[UIImageView alloc]init];

[self.backgrounView setImage:[UIImage imageNamed:@"背景图片.jpg"]];

[self.view addSubview:self.backgrounView];

WeakSelf(weakSelf);

[self.backgrounView mas_makeConstraints:^(MASConstraintMaker *make) {

make.edges.equalTo(weakSelf.view);

}];

}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event { //在这不创建按钮 使用系统的触摸事件

//开启上下文（开始绘制图片）

UIGraphicsBeginImageContext(self.view.frame.size);

//获取上下文（绘制内容）

CGContextRef context = UIGraphicsGetCurrentContext();

//把控制器的view的内容画到上下文当中

[self.view.layer renderInContext:context];

//从上下文当中生成一张图片

self.captureImage = UIGraphicsGetImageFromCurrentImageContext();

//关闭上下文（绘制结束）

UIGraphicsEndImageContext();

self.captureView = [[UIView alloc]init];

[self.captureView setFrame: [UIScreen mainScreen].bounds];

//应用这种形式设置透明度

self.captureView.backgroundColor = [UIColor colorWithRed:255 / 255.0 green:255 / 255.0 blue:255 / 255.0 alpha:0.5];

/*

//这个种方法设置透明度 会影响子视图的透明度

self.captureView.backgroundColor = [UIColor blackColor];

self.captureView.alpha = 0.5;

*/

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapgesture)];

tap.numberOfTouchesRequired = 1;

tap.numberOfTapsRequired = 1;

[self.captureView addGestureRecognizer:tap];

[[UIApplication sharedApplication].keyWindow addSubview:self.captureView];

[self.captureView addSubview:self.alertview];

self.captureImageView = [[UIImageView alloc]init];

[self.alertview addSubview: self.captureImageView];

[self.captureImageView setImage:self.captureImage];

WeakSelf(weakSelf);

[self.alertview mas_makeConstraints:^(MASConstraintMaker *make) {

make.top.equalTo(weakSelf.captureView).offset(84);

make.left.equalTo(weakSelf.captureView).offset(20);

make.right.equalTo(weakSelf.captureView).offset(-20);

make.bottom.equalTo(weakSelf.captureView).offset(-64);

}];

[self.captureImageView mas_makeConstraints:^(MASConstraintMaker *make) {

make.edges.equalTo(weakSelf.alertview);

}];

}

- (void)tapgesture { //移除视图

[self.captureView removeFromSuperview];

}