将照片库中的多张图片导入到 App

Question

我正在尝试创建一个应用程序，让您可以从照片库中导入照片并将它们插入指定的 UIImageViews。我能够让它在我的界面中为其中一个 UIImageView 工作，但无法分配给第二个 UIImageView。

如果有人能告诉我我做错了什么，我将不胜感激！谢谢！ SBB

这是我的代码：

@implementation FlipBook2ViewController


- (IBAction)selectExistingPicture {
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypePhotoLibrary]) {
        UIImagePickerController *picker =
        [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsImageEditing = NO;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        [self presentModalViewController:picker animated:YES];
        [picker release];
    }
    else {
        UIAlertView *alert = [[UIAlertView alloc] 
                              initWithTitle:@"Error accessing photo library" 
                              message:@"Device does not support a photo library" 
                              delegate:nil 
                              cancelButtonTitle:@"Dismiss" 
                              otherButtonTitles:nil];
        [alert show];
        [alert release];
    }
}


- (IBAction)selectExistingPicture2 {
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypePhotoLibrary]) {
        UIImagePickerController *picker =
        [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsImageEditing = NO;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        [self presentModalViewController:picker animated:YES];
        [picker release];
    }
    else {
        UIAlertView *alert = [[UIAlertView alloc] 
                              initWithTitle:@"Error accessing photo library" 
                              message:@"Device does not support a photo library" 
                              delegate:nil 
                              cancelButtonTitle:@"Dismiss" 
                              otherButtonTitles:nil];
        [alert show];
        [alert release];
    }
}


#pragma mark  -
- (void)imagePickerController:(UIImagePickerController *)picker 
        didFinishPickingImage:(UIImage *)image
                  editingInfo:(NSDictionary *)editingInfo {
    imageView.image = image;
    [picker dismissModalViewControllerAnimated:YES];

}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {

    [picker dismissModalViewControllerAnimated:YES];
}

Answer 1

您在委托方法imagePickerController:didFinishPickingImage:editingInfo: 中的imageView 没有改变。您可能应该有一个用于当前图像视图的实例变量，比如currentImageView，它们实现了委托方法，例如，

- (void)imagePickerController:(UIImagePickerController *)picker 
        didFinishPickingImage:(UIImage *)image
                  editingInfo:(NSDictionary *)editingInfo {
    currentImageView.image = image;
    [picker dismissModalViewControllerAnimated:YES];

}

但要使其正常工作，您必须稍微更改您的 selectExistingPicture。

- (IBAction)selectExistingPicture {
    if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypePhotoLibrary]) {

        currentImageView = imageView1; // Set it to the image view that will get changed

        [..]
    }
    else {
        [..]
    }
}

但是，您必须对每种方法都执行此操作。我不确定此方法的确切触发器是什么，但在操作方法中包含 sender 参数以避免重复是合适的。

- (IBAction)selectExistingPicture:(id)sender {
    switch(sender.tag) {
        /* set `currentImageView` based on the tag */
    }

    /* Rest of your method from the question remains the same */
}