UIImagePickerController没有加载到iPhone SDK的viewDidLoad中

Question

I'm trying to show a UIImagePickerController as soon as one of my view controller loads. I'd like to this without the user having to press a button so I overrode the viewDidLoad method as follows:

- (void)viewDidLoad {
    [super viewDidLoad];

    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    imagePickerController.allowsImageEditing = YES;
    imagePickerController.delegate = self;    
    [self presentModalViewController:imagePickerController animated:YES];
    [imagePickerController release];
}

This compiles and runs, however when the view controller is loaded the image picker is not displayed. This code works fine if I attach it to an event of a button for example. Any ideas?

Thanks.

Answer 1

I had the same problem but solved it. Try using

-(void) awakeFromNib {

}

It will load just after everything else loads.

Answer 2

Try putting the code in

-(void)viewDidAppear

That even runs every time the view appears on the screen though (including when it appears after you dismiss the UIImagePicker), so you might have to add a BOOL value to make it only happen the first time it shows, or when you want it (ie not after dismissing a modal view).

Answer 3

It seems that viewDidLoad is too early to use presentModalViewController:animated:. I'd sugget to fork off a one-shot timer to call the method from next run loop iteration:

[NSTimer
 scheduledTimerWithTimeInterval:0
 target:self
 selector:@selector(onLoadTimer:)
 userInfo:nil
 repeats:NO];

add the following method:

- (void)onLoadTimer:(id)unused
{
    [self presentModalViewController:imagePickerController animated:YES];
    [imagePickerController release];
}