objective-c - 如何使用 UIPopOverController 制作一个在 iPhone 上使用 ImagePicker 的 iPhone 应用程序？

Question

我正在制作一个通用应用程序，它在 iPhone 上运行良好!但在 iPad 上，它无法拉起图像选择器。代码是:

- (IBAction)openImagePicker:(id)sender //Makes UIImagePicker roll up from the bottom.
{
    UIActionSheet *alertSheet = [[UIActionSheet alloc] initWithTitle:@"Where do you want to get your daily image?" delegate:(self) cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Camera", @"Library", nil];
    [alertSheet setTag:0];
    [alertSheet setDelegate:self];
    [alertSheet showFromTabBar:[[self tabBarController] tabBar]];
    [alertSheet release];
}

它说原因是“* 由于未捕获的异常‘NSInvalidArgumentException’而终止应用程序，原因:‘在 iPad 上，UIImagePickerController 必须通过 UIPopoverController 呈现’”我该怎么做？感谢您的帮助。

Answer 1

您必须检查应用程序安装在哪种类型的设备上，然后适本地显示 Controller 。您可以按照以下方式执行操作:

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
    // We are using an iPhone
    UIActionSheet *alertSheet = [[UIActionSheet alloc] initWithTitle:@"Where do you want to get your daily image?" delegate:(self) cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Camera", @"Library", nil];
    [alertSheet setTag:0];
    [alertSheet setDelegate:self];
    [alertSheet showFromTabBar:[[self tabBarController] tabBar]];
    [alertSheet release];
}else {
    // We are using an iPad
    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.delegate = self;
    UIPopoverController *popoverController=[[UIPopoverController alloc] initWithContentViewController:imagePickerController];
    popoverController.delegate=self;
    [popoverController presentPopoverFromRect:((UIButton *)sender).bounds inView:sender permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
}

不要忘记实现 UIPopoverController 委托(delegate)方法。

祝你好运