iphone - IOS 开发，使用 UIImagePickerController 并按下使用会使应用卡住(不崩溃)

Question

任何人都可以帮我解决这个问题吗？

在我的最后一个问题中，我使用的是带有 3 个选项卡项的 tabBarController。第三个选项卡有一个 uiViewController，里面有一个 UIImagePickerController(一个相机)。

现在每件事都在工作，除了一件事。当用相机拍摄图像并按“使用”时，我收到图像已保存的警报，我可以在相册中看到它(如果我关闭应用程序并查看它)但应用程序卡在这个位置我不能再做任何事情了。我可以在屏幕上看到图像，并且“使用”和“重拍”按钮不可用。就这样卡住了。

谁能看到我在这里做错了什么？

附言。在所有示例和教程中，我发现取消选择器中有一个版本......(也在我的代码中)。在我的例子中，选择器是 View Controller (imgPicker)的一个属性，我像往常一样在 dealloc 方法中释放它，这是写还是错？我应该这样生活还是我在这里做坏内存(我在这里没有得到任何“坏内存错误”，但这可能是我的错误......)？

我在 viveWillAppear 委托(delegate)方法中加载 UIImagePicker。
每件事都在同一个 TakePhotoViewController.m 文件中......

-(void) viewWillAppear:(BOOL)animated{
    self.imgPicker = [[UIImagePickerController alloc] init];
    self.imgPicker.allowsEditing = NO;
    self.imgPicker.delegate = self;
    self.imgPicker.sourceType = UIImagePickerControllerSourceTypeCamera;
    [self presentModalViewController:imgPicker animated:YES];  
}

和委托(delegate)方法:

#pragma mark -
#pragma mark - UIImagePicker delegate methods

//saving the image that was taken
- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo: (NSDictionary *)info
{
    // Access the uncropped image from info dictionary
    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

    // Save image
    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);

    [picker release];
}

//alerting the user if the images was saved or not
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
    UIAlertView *alert;

    // Unable to save the image  
    if (error)
        alert = [[UIAlertView alloc] initWithTitle:@"Error" 
                                       message:@"Unable to save image to Photo Album." 
                                      delegate:self cancelButtonTitle:@"Ok" 
                             otherButtonTitles:nil];
    else // All is well
        alert = [[UIAlertView alloc] initWithTitle:@"Success" 
                                       message:@"Image saved to Photo Album." 
                                      delegate:self cancelButtonTitle:@"Ok" 
                             otherButtonTitles:nil];
    [alert show];
    [alert release];
}

//if user is cancelling the camera
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
    [self.tabBarController setSelectedIndex:0];
}

非常感谢你，
埃雷兹

Answer 1

您在取消操作上处于正确的轨道上，但在其他操作中未能做到这一点:

您需要在每次操作后在 ViewController 上调用dismiss。

http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html

编辑:新链接 https://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html#//apple_ref/doc/uid/TP40007070

... However, if you set this property to YES, your delegate must dismiss the image picker interface after the user takes one picture or cancels the operation.

所以，如果需要拍摄多于1张图片，showCameraControls需要设置为NO，并且需要使用自己的CameraOverlayView。

另外，绝对不要在你的代表中释放选择器!当 ViewController 弹出 View 时，它会自动释放它(假设选择器没有被保留在其他地方)。经验法则，如果您不拥有(保留)它，请不要释放它。 (一旦 iOS5 ARC 普及，这个概念可能会被遗忘)

您可能应该在 ViewController 呈现后释放它。

iPhone - modalViewController release

编辑:更多代码来帮助

-(void) viewWillAppear:(BOOL)animated{
    // No need to store... this is 1 use only anyway. Save memory, and release it when done.
    UIImagePickerController *imgPicker = [[UIImagePickerController alloc] init];
    imgPicker.allowsEditing = NO;
    imgPicker.delegate = self;
    imgPicker.sourceType = UIImagePickerControllerSourceTypeCamera;

    [self presentModalViewController:imgPicker animated:YES];
    [imgPicker release]; // Release this here, this will execute when modal view is popped. 
}

代表:

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo: (NSDictionary *)info
{
    /* Do what you need to do then */
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
}

//alerting the user if the images was saved or not
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
    /* Do what you need to do then */
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
}

//if user is cancelling the camera
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    /* Do what you need to do then */
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
}