文字与图片
UIImage *image = self.showedImageView.image; //获取一张图片
UIGraphicsBeginImageContext(image.size); //开启上下文
[image drawInRect:CGRectMake(0, 0, w, h)]; //图片绘画
NSDictionary *attr = @{NSFontAttributeName:[UIFont monospacedDigitSystemFontOfSize:268 weight:10],NSForegroundColorAttributeName:[UIColor redColor],NSStrokeColorAttributeName:[UIColor lightGrayColor]};
[mark drawInRect:CGRectMake(110, 80, w, h) withAttributes:attr];// 文字绘制
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();// 获取到新绘制的图片
UIGraphicsEndImageContext(); // 关闭上下文
图片与图片
UIGraphicsBeginImageContextWithOptions(useImage.size, NO, 0.0);
[useImage drawInRect:CGRectMake(0, 0, useImage.size.width, useImage.size.height)]; //背景图片
[maskImage drawInRect:CGRectMake(0, 0, useImage.size.width/2, useImage.size.height/2)];
UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();