Question

我使用了一个很棒的教程（http://iphone.zcentric.com/2008/08/28/using-a-uiimagepickercontroller/）来使用UIImagePickerController从iPhone上的相册或相机中获取图像。问题是，该教程有点过时，文档引用了委托使用的方法，因为自3.0以来已经过折旧。问题是，文档未能提供关于使用什么的线索？不推荐使用的方法是：

– imagePickerController:didFinishPickingImage:editingInfo:

以上方法使用如下：

- (void) imagePickerController:(UIImagePickerController*)picker didFinishPickingImage:(UIImage*)img editingInfo:(NSDictionary*)editInfo
{

    image.image = img;
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];


}

问题：目前使用什么代替弃用方法？

Answer 1

以下是如何使用新的图像选择器API。

首先，你需要一个这样声明的类，因为它将自己设置为图像选择器委托：

@interface MyClass : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate> {
UIImagePickerController*    imagePicker;
}
@property(nonatomic,retain) UIImagePickerController* imagePicker;

- (IBAction) takePicture:(id)sender;

@end

调出图像选择器的方法就是这样的。它在此处声明为IBAction，因此您可以直接将其连接到Interface Builder中的控件（如按钮）。它还检查，如果你在iPhone上，它会调出相机界面，但在iPod Touch上它会调出图库选择器：

#import <MobileCoreServices/UTCoreTypes.h>
...
@synthesize imagePicker = _imagePicker;
...

- (void) takePicture:(id)sender
{
        if (!_imagePicker) {
            self.imagePicker = [[UIImagePickerController alloc] init];
            self.imagePicker.delegate = self;
        }

        if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
            self.imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
            NSArray* mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
            self.imagePicker.mediaTypes = mediaTypes;
        } else {
            self.imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; 
            self.imagePicker.allowsImageEditing = YES; 
        }

    [self presentModalViewController:self.imagePicker animated:YES];
}

然后你需要这两种方法：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [[picker parentViewController] dismissModalViewControllerAnimated:YES]; 

    // MediaType can be kUTTypeImage or kUTTypeMovie. If it's a movie then you
    // can get the URL to the actual file itself. This example only looks for images.
    //   
    NSString* mediaType = [info objectForKey:UIImagePickerControllerMediaType];
    // NSString* videoUrl = [info objectForKey:UIImagePickerControllerMediaURL];

    // Try getting the edited image first. If it doesn't exist then you get the
    // original image.
    //
    if (CFStringCompare((CFStringRef) mediaType, kUTTypeImage, 0) == kCFCompareEqualTo) {       
        UIImage* picture = [info objectForKey:UIImagePickerControllerEditedImage];
        if (!picture)
            picture = [info objectForKey:UIImagePickerControllerOriginalImage];     

            // **You can now do something with the picture.
    }
    self.imagePicker = nil;
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker 
{ 
    [[picker parentViewController] dismissModalViewControllerAnimated:YES]; 
    self.imagePicker = nil;
}

Answer 2

引用Apple文档：

imagePickerController:didFinishPickingImage:editingInfo:
告诉代表用户选择了一张图片。此方法是可选的。（在iPhone OS 3.0中不推荐使用。 使用 imagePickerController:didFinishPickingMediaWithInfo: 而不是。）

用什么来代替弃用的UIImagePickerControllerDelegate方法？

2 个答案: