iOS UIImagePickerController和ModalViewController

Question

我写了一段代码，它在基于PhoneGap的应用程序中运行。该代码有一个插件，它可以在使用以下代码单击网页上的某个绑定按钮时启动UIImagePickerController。

PhotoSelectorCommand.h

#import <Foundation/Foundation.h> 
#import "PhoneGapCommand.h" 

@interface PhotoSelectorCommand : PhoneGapCommand<UINavigationControllerDelegate, UIImagePickerControllerDelegate> { 
    NSString *url; 
    NSString *extra; 
} 

@property (nonatomic, copy) NSString *url; 
@property (nonatomic, copy) NSString *extra; 

- (void) startPhotoSelector:(NSMutableArray *)arguments withDict:(NSMutableDictionary *)options; 
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info; 
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker; 

@end 

PhotoSelectorCommand.m

#import "PhotoSelectorCommand.h" 
#import "PhoneGapViewController.h" 
#import "PhotoUploaderViewController.h" 

@implementation PhotoSelectorCommand 

@synthesize url; 
@synthesize extra; 

- (void) startPhotoSelector:(NSMutableArray*)arguments withDict:(NSMutableDictionary*)options // args: url 
{ 
    NSUInteger argc = [arguments count]; 

    if (argc < 1) { 
     return; 
    } 
    self.url = [arguments objectAtIndex:0]; 
    if (argc > 1) { 
     self.extra = [arguments objectAtIndex:1]; 
    } 

    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init]; 
    imagePicker.delegate = self; 
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; 

    PhoneGapViewController* cont = (PhoneGapViewController *)[super appViewController]; 
    [cont presentModalViewController:imagePicker animated:YES]; 
} 

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

    [picker dismissModalViewControllerAnimated:YES]; 

    PhotoUploaderViewController *photoUploader = [PhotoUploaderViewController alloc]; 

    PhoneGapViewController* cont = (PhoneGapViewController *)[super appViewController]; 

    [cont presentModalViewController:photoUploader animated:YES]; 

    [photoUploader.view removeFromSuperview]; 
    [picker release]; 

    [picker.view removeFromSuperview]; 
    [picker release]; 
} 

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker { 
    //on cancel 
    NSString *failureCallback = [NSString stringWithFormat:@"PhotoSelector._onError('%@');", @"No image selected."]; 
    [webView stringByEvaluatingJavaScriptFromString:failureCallback]; 

    [picker dismissModalViewControllerAnimated:YES]; 
    [picker.view removeFromSuperview]; 
    [picker release]; 
} 

@end 

PhotoSelectorViewController.h

#import <UIKit/UIKit.h> 

@interface PhotoUploaderViewController : UIViewController { 

} 

@end 

PhotoSelectorViewController.m

#import "PhotoSelectorViewController.h" 

@implementation PhotoSelectorViewController 

-(void)init { 
} 
- (void)viewDidLoad { 
    [super viewDidLoad]; 
} 
- (void)didReceiveMemoryWarning { 
    // Releases the view if it doesn't have a superview. 
    [super didReceiveMemoryWarning]; 
} 
- (void)viewDidUnload { 
    [super viewDidUnload]; 
} 
- (void)dealloc { 
    [super dealloc]; 
} 

@end 

上面的代码工作，直到它显示UIImagePickerController用户可以选择图像。一旦选择任何图像后，控制器会关闭，但另一个视图不会像UIImagePickerController一样呈现。任何想法为什么？

Answer 1

我不知道你为什么拒绝选择器？只有在控制器被解雇后才会调用该方法。另外，您正在释放拾取器两次，并从removerFromSuperView？请尝试使用以下代码并查看注释行。

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

    // [picker dismissModalViewControllerAnimated:YES]; you need not to do this 

    PhotoUploaderViewController *photoUploader = [PhotoUploaderViewController alloc]; 

    PhoneGapViewController* cont = (PhoneGapViewController *)[super appViewController]; 

    [cont presentModalViewController:photoUploader animated:YES]; 

    // [photoUploader.view removeFromSuperview]; // where you have added this view? 
    // [picker release]; //you do not own this object.. 

    //[picker.view removeFromSuperview]; // and ? 
    //[picker release]; // same here 
}