如何在Xamarin.iOS中获取照片的字节[]

Question

我正在Xamarin.iOS中开发一个摄影软件。我正在使用PHPhoto类。

当我拍摄照片时，我会尝试将其发送到网络上。我计划用字节[]发送它们。在哪里可以获得DidFinishCapture方法中的照片数据？当我开始调试启动时，我看到PHPhotoLibrary.SharedPhotoLibrary.PerformChanges((将自动将照片保存到照片库中。

如何按字节[]检索照片？我在PhotoData中找不到它。

我以为LivePhotoCompanionMovieUrl中有一个保存照片的路径，但这总是空的。

public partial class PhotoCaptureDelegate : AVCapturePhotoCaptureDelegate
{
public override void DidFinishCapture(AVCapturePhotoOutput captureOutput, 
AVCaptureResolvedPhotoSettings resolvedSettings, 
NSError error)
{
PHPhotoLibrary.RequestAuthorization(status =>
{
if (status == PHAuthorizationStatus.Authorized)
{
PHPhotoLibrary.SharedPhotoLibrary.PerformChanges(() =>
{
var creationRequest = PHAssetCreationRequest.CreationRequestForAsset();
creationRequest.AddResource(PHAssetResourceType.Photo, PhotoData, null);
var url = LivePhotoCompanionMovieUrl;
if (url != null)
{
var livePhotoCompanionMovieFileResourceOptions = new PAssetResourceCreationOptions
{
ShouldMoveFile = true
};
creationRequest.AddResource(PHAssetResourceType.PairedVideo, url, livePhotoCompanionMovieFileResourceOptions);
}
}, (success, err) =>
{
if (err != null)
Debug.WriteLine($"Error occurered while saving photo to photo library: {error.LocalizedDescription}");
});
}
});
}
}
}

Answer 1

如果您想将照片转换为Byte数组，可以使用Nuget的插件Media.plugin来拾取或拍照。

await CrossMedia.Current.Initialize();

if (!CrossMedia.Current.IsCameraAvailable || !CrossMedia.Current.IsTakePhotoSupported)
{
DisplayAlert("No Camera", ":( No camera available.", "OK");
return;
}
var file = await CrossMedia.Current.TakePhotoAsync(new Plugin.Media.Abstractions.StoreCameraMediaOptions
{
SaveToAlbum = true,
Name = "test.jpg"
});
if (file == null)
return;

然后先将其转换为Stream，然后再将其转换成字节数组。

Stream stream = file.GetStream();

public byte[] GetImageStreamAsBytes(Stream input)
{
var buffer = new byte[16*1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}

现在您可以获得如下所示的字节数组

var imgDate = GetImageStreamAsBytes(stream);

更新

您可以使用UIImagePickerController

UIImagePickerController imagePicker;

并在需要拍照时调用以下行

imagePicker = new UIImagePickerController
{
SourceType = UIImagePickerControllerSourceType.Camera,
MediaTypes = UIImagePickerController.AvailableMediaTypes(UIImagePickerControllerSourceType.Camera)
};
// Set event handlers
imagePicker.FinishedPickingMedia += ImagePicker_FinishedPickingMedia; ;
imagePicker.Canceled += ImagePicker_Canceled; ;
// Present UIImagePickerController;
this.PresentViewController(imagePicker, true, null);

private void ImagePicker_Canceled(object sender, EventArgs e)
{
imagePicker.DismissModalViewController(true);
}
private void ImagePicker_FinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs args)
{
UIImage image = args.EditedImage ?? args.OriginalImage;
if (image != null)
{
// Convert UIImage to .NET Stream object
NSData data;
if (args.ReferenceUrl.PathExtension.Equals("PNG") || args.ReferenceUrl.PathExtension.Equals("png"))
{
data = image.AsPNG();
}
else
{
data = image.AsJPEG(1);
}
Stream stream = data.AsStream();

}
else
{

}
imagePicker.DismissModalViewController(true);
}

public byte[] GetImageStreamAsBytes(Stream input)
{
var buffer = new byte[16*1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}

现在您可以获得如下所示的字节数组

var imgDate = GetImageStreamAsBytes(stream);