我如何避免在AlAssetLibrary位置服务?我可以检索文件使用AlAssetLibrary不使用位置服务

Question

我创建了一个应用程序，使用ALAssetLibrary从iPhone照片文件夹中获取图像。我可以检索文件使用AlAssetLibrary不使用位置服务?我如何避免在AlAssetLibrary位置服务?

Answer 1

目前没有办法访问ALAssetLibrary不使用位置服务。你必须使用更有限的UIImagePickerController来解决这个问题

Answer 2

如果您只需要库中的一张图像，则上述答案是不正确的。例如，如果您让用户选择要上传的照片。在这种情况下，你可以用ALAssetLibrary获得单个图像，而不需要Location权限。

要做到这一点，使用UIImagePickerController来选择图片;你只需要UIImagePickerControllerReferenceURL，它由UIImagePickerController提供。

这样做的好处是允许您访问未修改的NSData对象，然后可以上传该对象。

这很有帮助，因为稍后使用UIImagePNGRepresentation()或UIImageJPEGRepresentation()重新编码图像可以使文件大小增加一倍!

显示选择器:

picker = [[UIImagePickerController alloc] init];
[picker setDelegate:self];
[picker setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
[self presentViewController:picker animated:YES completion:nil];

获取图像和/或数据:

- (void)imagePickerController:(UIImagePickerController *)thePicker didFinishPickingMediaWithInfo:(NSDictionary *)info
{   
    [picker dismissViewControllerAnimated:YES completion:nil];
    NSURL *imageURL = [info objectForKey:@"UIImagePickerControllerReferenceURL"];
    ALAssetsLibrary *assetLibrary=[[ALAssetsLibrary alloc] init];
    [assetLibrary assetForURL:imageURL
                  resultBlock:^(ALAsset *asset) {
                      // get your NSData, UIImage, or whatever here
                     ALAssetRepresentation *rep = [self defaultRepresentation];
                     UIImage *image = [UIImage imageWithCGImage:[rep fullScreenImage]];
                     Byte *buffer = (Byte*)malloc(rep.size);
                     NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:rep.size error:nil];
                     NSData *data = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];
                     if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
                         UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
                     }
                 }
                 failureBlock:^(NSError *err) {
                     // Something went wrong; get the image the old-fashioned way                            
                     // (You'll need to re-encode the NSData if you ever upload the image)
                     UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
                     if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
                         UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
                     }
                 }];
}