处理设备照片时 iOS ImageView 裁剪不起作用

Question

我计划创建一个图像编辑应用程序。第一步，我要将图像的触摸位置显示到与原始 ImageView 不同的 ImageView 中。

在使用默认图像(从 xcode storyboard attribute inspector 设置)进行测试时，它工作正常。

但是当我从设备“照片”导入照片时，它不会裁剪出精确的图像。

我真的很困惑，一直卡在那里。请有人指导我完成这项任务。

我试过下面的代码

提前致谢。

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{

    UIImage *image = [info valueForKey:UIImagePickerControllerEditedImage];
    imgVw.image = image;

//    croperImgvw.image = [self cropImage : image];

    [self dismissViewControllerAnimated:YES completion:NULL];
}


- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [self dismissViewControllerAnimated:YES completion:NULL];
}



- (UIImage *)cropImage:(UIImage *)image : (CGPoint)point
{

    CGRect clippedRect =CGRectMake(point.x, point.y, 50, 50);
    CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], clippedRect);
    UIImage * croppedImage = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);
    return croppedImage;


}



-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{

    UITouch *touch = [touches anyObject];

    CGPoint touch_point = [touch locationInView:self.view];


    NSLog(@"X location: %f", touch_point.x);
    NSLog(@"Y Location: %f",touch_point.y);

    CGPoint point = [touch locationInView:self.view];

    croperImgvw.image = [self cropImage:[imgVw image] :point];


}

Answer 1

据我了解，您传递给 cropImage:image: 方法的 point 参数来自 UIImageView 坐标系 - CGImageCreateWithImageInRect 中的 rect 参数必须取自 UIImage ，而不是来自 UIImageView。

这里有几个关于如何解决这个问题的答案:

https://stackoverflow.com/a/10865552/4495995

https://stackoverflow.com/a/21693491/4495995