如何在iphone中裁剪特定图像

Posted 2023-02-25

【中文标题】如何在iphone中裁剪特定图像

【英文标题】：How to crop a particular image in iphone

【发布时间】：2011-08-10 06:22:47

【问题描述】：

我正在开发相机应用程序，用户正在拍照，但我想裁剪该图像中的任何位置并将其发送到服务器。我该怎么做？

【问题讨论】：

你应该接受一些答案......

你想要这个....link

看这个。我想你想要同样的link

【参考方案1】：

查看此链接了解详情：

http://www.hive05.com/2008/11/crop-an-image-using-the-iphone-sdk/

基本代码：

- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect

   //create a context to do our clipping in
   UIGraphicsBeginImageContext(rect.size);
   CGContextRef currentContext = UIGraphicsGetCurrentContext();

   //create a rect with the size we want to crop the image to
   //the X and Y here are zero so we start at the beginning of our
   //newly created context
   CGRect clippedRect = CGRectMake(0, 0, rect.size.width, rect.size.height);
   CGContextClipToRect( currentContext, clippedRect);

   //create a rect equivalent to the full size of the image
   //offset the rect by the X and Y we want to start the crop
   //from in order to cut off anything before them
   CGRect drawRect = CGRectMake(rect.origin.x * -1,
                                rect.origin.y * -1,
                                imageToCrop.size.width,
                                imageToCrop.size.height);

   //draw the image to our clipped context using our offset rect
   CGContextDrawImage(currentContext, drawRect, imageToCrop.CGImage);

   //pull the image from our cropped context
   UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();

   //pop the context to get back to the default
   UIGraphicsEndImageContext();

   //Note: this is autoreleased
   return cropped;

【参考方案2】：

我认为我可以为大量代码提供更好的解决方案。

- (void)viewDidLoad

    [super viewDidLoad];
    // do something......
    UIImage *croppedImage = [self imageByCropping:[UIImage imageNamed:@"SomeImage.png"] toRect:CGRectMake(10, 10, 100, 100)];

- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect

   CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect);
   UIImage *cropped = [UIImage imageWithCGImage:imageRef];
   return cropped;

【讨论】：

感谢@robin 回答我。请让我知道我把他的代码放在哪里。

好的，我想在 viewdidload 方法上调用它如何调用它。我正在写 [self imageToCrop]；它给出了错误。请告诉我怎么写。

我的图片尺寸是150 * 120（宽*高）

您是否在视图中的某个位置显示此图像。你也可以告诉我你打算如何发送这张图片。