objective-c - imagepicker 控制器在为 iphone 模拟器 3.0 构建时显示错误

Question

我正在开发一个同时使用视频录制和照片拍摄的应用程序。所以我想根据操作系统显示按钮，为此我实现了这些方法。当我为 OS 3.1 构建时它工作正常，但当我为 OS 3.0 构建时它显示错误

这是方法

    if ([self videoRecordingAvailable])
    {
        imagePickerController.sourceType =  UIImagePickerControllerSourceTypeCamera;
        imagePickerController.allowsImageEditing = YES;
        imagePickerController.allowsEditing = YES;
        imagePickerController.videoQuality = UIImagePickerControllerQualityTypeHigh;
        imagePickerController.videoMaximumDuration = 60.0f; // Length for video recording in seconds
        imagePickerController.mediaTypes = [NSArray arrayWithObjects:@"public.movie", nil];
        imagePickerController.showsCameraControls=YES;      
        [self.navigationController presentModalViewController:imagePickerController animated:YES];          
    }


- (BOOL) videoRecordingAvailable
{
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) return NO;
return [[UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera] containsObject:@"public.movie"];
}

错误是

error: request for member 'allowsEditing' in something not a structure or union
error: request for member 'videoQuality' in something not a structure or union
error: 'UIImagePickerControllerQualityTypeHigh' undeclared (first use in this function)
 (Each undeclared identifier is reported only once for each function it appears in.)
error: request for member 'videoMaximumDuration' in something not a structure or union
error: request for member 'showsCameraControls' in something not a structure or union

我该如何解决这个问题？

Answer 1