截取屏幕指定区域的UI生成图片

截取某部分区域生成图片

- (void)cutScreenWithView:(nullable UIView *)view successBlock:(nullable void(^)(UIImage * _Nullable image,NSData * _Nullable imagedata))block {
    //1、开启上下文
    UIGraphicsBeginImageContextWithOptions(view.layer.size,NO, 0.0);
    //2.获取当前上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    
    //3.截屏
    [view.layer renderInContext:ctx];
    
    //字符串
    NSString * nameStr = @"字符串";
    [nameStr drawInRect:CGRectMake(105, 168, 300, 50) withAttributes:@{NSFontAttributeName:kFont(14),NSForegroundColorAttributeName:UIColor.blackColor}];  //画字符串
    
    //4、获取新图片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    //5.转化成为Data
    //compressionQuality:表示压缩比 0 - 1的取值范围
    NSData *data = UIImageJPEGRepresentation(newImage, 1);
    //6、关闭上下文
    UIGraphicsEndImageContext();
    //7.回调
    block(newImage, data);
}

- (void)drawRect:(CGRect)rect {
    [self cutScreenWithView:self.bgImageView successBlock:^(UIImage * _Nullable image, NSData * _Nullable imagedata) {
        self.shareImage = image;
    }];
}