Ios 从选定区域中的uiimagepickerviewcontroller裁剪图像

拍摄图像时，如何从选定区域的

UIImagePickerController

裁剪图像。覆盖代码下方的UIImagePickerController的视图

-(UIImage *)centerCropImage:(UIImage *)image
{
   // Use smallest side length as crop square length
   CGFloat squareLength = MIN(image.size.width, image.size.height);
   // Center the crop area
   CGRect clippedRect = CGRectMake((image.size.width - squareLength) / 2, (image.size.height - squareLength) / 2, squareLength, squareLength);
   // Crop logic
   CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], clippedRect);
   UIImage * croppedImage = [UIImage imageWithCGImage:imageRef];
   CGImageRelease(imageRef);
   return croppedImage;
}

然后在imagePickerViewDelegate方法中

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *image = [info objectForKey: @"UIImagePickerControllerOriginalImage"];
    [self centerCropImage:image]; //Just give your image here for cropping
    yourImage.image=image; 
    picker.delegate =self;
    [picker dismissViewControllerAnimated:YES completion:nil];
}

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你做了什么检查我是否已从

UIImagePickerController

捕获图像，但我需要裁剪区域部分。当我当时单击捕获按钮时，我有一个问题，该方法称为…？？您的按钮操作方法称为。之后，当您从照片库中选择图像并通过相机时，调用imagePickerViewDelegate方法。该方法是didFinishPickingMediaWithInfo。当UIImagePickerController在此时打开捕获按钮时，单击该时间使用的方法…？此时它正在调用以下按钮行操作UIImagePickerController*picker=[[UIImagePickerController alloc]init]；picker.delegate=self；picker.allowsdediting=是；picker.sourceType=UIImagePickerController源类型摄像头；[自我呈现视图控制器：选择器动画：是完成：空]；