ios - UIImagePickerController + 裁剪 : what does allowEditing and what does it not?

Question

阅读文档和sample code from apple后关于 UIImagePickerController 并阅读了许多教程甚至 Questions在 Stackoverflow(or here)，我得出结论，内置的 UIImagePicker 能够向用户呈现一个“裁剪窗口”，让用户裁剪并移动他想要使用的图像的正确部分。

但是在 iOS 7.1 上检查这些示例，没有出现裁剪窗口。似乎没有什么可以让用户裁剪掉所拍摄图像的一部分。所有测试均在真实硬件(iPhone 5S)上进行，由于缺少摄像头，此处未使用 iPhone 模拟器 ;)

此外，在委托(delegate)方法“didFinishPickingMediaWithInfo”中，“信息”-NSDictionary 中没有“UIImagePickerControllerEditedImage”条目。

我做了什么:

    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];

#if TARGET_IPHONE_SIMULATOR
    // iPhone-Simulator has no camera, just save images to the photoalbum on the simulator to use them here
    imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
#else
    imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
#endif

    imagePickerController.editing = YES;
    imagePickerController.delegate = (id)self;
    imagePickerController.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;


    [self presentModalViewController:imagePickerController animated:YES];

和委托(delegate)方法:

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
        // .... do something 
}

此时，Dictionary 中只有 3 个名为“info”的 Keys 可用:

• UIImagePickerControllerOriginalImage
• UIImagePickerControllerMediaMetadata
• UIImagePickerControllerMediaType

没有别的。此外，没有出现裁剪窗口或任何类似的控件。

我对 ImagePicker 行为的预期有误吗？在此 SF-Question 中，用户写道 "Crop window comes up" .该功能被删除了吗？文档是否过时或我在这里完全错了？

我还尝试了从另一个 answer to a similar question 获取的代码:

- (void)    imagePickerController:(UIImagePickerController *)picker 
    didFinishPickingMediaWithInfo:(NSDictionary *)info 
{
    [picker dismissViewControllerAnimated:YES completion:^{
          // Edited image works great (if you allowed editing)
        UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
          // AND the original image works great
        UIImage *originalImage = [info objectForKey:UIImagePickerControllerOriginalImage];
          // AND do whatever you want with it, (NSDictionary *)info is fine now
        UIImage *myImage = [info objectForKey:UIImagePickerControllerEditedImage];
    }];
}

没有出现裁剪窗口，信息 NSDictionary 中不存在键“UIImagePickerControllerEditedImage”。

有人可以向我解释正确的行为吗？非常感谢您。

Answer 1

这个适合我:

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *originalImage, *editedImage;

    editedImage = (UIImage *) [info objectForKey:UIImagePickerControllerEditedImage];
    originalImage = (UIImage *) [info objectForKey:UIImagePickerControllerOriginalImage];

    if (editedImage)
        self.profilePictureImageView.image = editedImage;
    else
        self.profilePictureImageView.image = originalImage;

    [picker dismissViewControllerAnimated:YES completion:nil];
}