iOS/Xcode异常：reason: Unable to load iPodUI.framework

在iOS 模拟器中测试音乐播放功能，使用多媒体选择器 MPMediaPickerController时，出现如下异常信息：

reason: Unable to load iPodUI.framework

模拟器无法访问设备的iPod 库，也就是无法访问设备的音乐库。

要测试这一功能，必须使用实际设备，代码可以改进一下，捕获这一异常信息。

- (IBAction)chooseMusic:(id)sender {
MPMediaPickerController *musicPicker;

musicPicker = [[MPMediaPickerController alloc] initWithMediaTypes:MPMediaTypeMusic];
musicPicker.prompt = @"请选择音乐";
musicPicker.allowsPickingMultipleItems = YES;
musicPicker.delegate = self;

@try {
[self presentViewController:musicPicker animated:YES completion:nil];
}
@catch (NSException *exception) {
[[[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Oops!",@"Error title")
message:NSLocalizedString(@"The music library is not available.",@"Error message when MPMediaPickerController fails to load")
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil] show];
}
}