将照片保存到相机胶卷并确保它实际保存

Question

我目前正在以这种方式将 UIImage 保存到相机胶卷。

UIImageWriteToSavedPhotosAlbum(finalPicture.image, nil, nil, nil);

但是如果用户拒绝我们访问他们的照片会发生什么...我如何判断这已经发生并显示错误消息？

Answer 1

为了将图像保存到相机胶卷，我使用了 ALAssetsLibrary，所以在方法中：

//Called after taking the photo with the camera or selected the image from the gallery  
- (void)imagePickerController:(UIImagePickerController *) Picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

NSURL *referenceURL;

if(Picker.sourceType==UIImagePickerControllerSourceTypeCamera){

    UIImage* takenImage=info[UIImagePickerControllerOriginalImage];

    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
    // Request to save the image to camera roll
    [library writeImageToSavedPhotosAlbum:[takenImage CGImage] orientation:(ALAssetOrientation)[takenImage imageOrientation] completionBlock:^(NSURL *assetURL, NSError *error){
        if (error) {
           //NOT SAVED
           //DISPLAY ERROR THE PICTURE CAN'T BE SAVED
        } else {
          //SAVED 
        }  
    }];        

 }
}else{
//Selected from gallery
}

还请记住，您必须先检查相机是否可用。

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        //The camera is available
    }else{
       //No camera available
    }