获取Xamarin图库图像的路径？

我正在尝试获取图库图像的路径。我正在获取存储在内部存储中但不是外部存储中的图像的路径。我还启用了已授予的读写存储和相机访问权限。 这是我的代码

    void ChoosePhoto()
    {
        try
        {
            var imageIntent = new Intent();
            imageIntent.SetType("image/*");
            imageIntent.SetAction(Intent.ActionGetContent);
            StartActivityForResult(Intent.CreateChooser(imageIntent, "Select photo"), 0);
        }
        catch (Exception ex)
        {
            throw ex;
        }
    } 

protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
    {
        base.OnActivityResult(requestCode, resultCode, data);

        if (requestCode == CAMERA_CAPTURE)
        {
        // camera operation
        }
        else
        {
            Console.WriteLine("choose pic from Gallery");
            var uri = data.Data;
            var path = getRealPathFromURI(uri); //path returns null when i select image from external storage;
        }
    }
    private String getRealPathFromURI(Uri contentURI)
    {
        string[] proj = { MediaStore.Images.ImageColumns.Data };
        String result;
        var cursor = ContentResolver.Query(contentURI, proj, null, null, null);
        if (cursor == null)
            result = contentURI.Path;
        else
        {
            int idx= cursor.GetColumnIndex(MediaStore.Images.ImageColumns.Data);
            cursor.MoveToFirst();
            result = cursor.GetString(idx);
            cursor.Close();
        }
        return result;
    }

我想获取我从图库中选择的图像路径

问题是改变Android.Net.Uri to path，这是一个解决方案：

private string GetPathToImage(Android.Net.Uri uri)
{
    string doc_id = "";
    using (var c1 = ContentResolver.Query(uri, null, null, null, null))
    {
        c1.MoveToFirst();
        string document_id = c1.GetString(0);
        doc_id = document_id.Substring(document_id.LastIndexOf(":") + 1);
    }

    string path = null;

    // The projection contains the columns we want to return in our query.
    string selection = Android.Provider.MediaStore.Images.Media.InterfaceConsts.Id + " =? ";
    using (var cursor = ContentResolver.Query(Android.Provider.MediaStore.Images.Media.ExternalContentUri, null, selection, new string[] { doc_id }, null))
    {
        if (cursor == null) return path;
        var columnIndex = cursor.GetColumnIndexOrThrow(Android.Provider.MediaStore.Images.Media.InterfaceConsts.Data);
        cursor.MoveToFirst();
        path = cursor.GetString(columnIndex);
    }
    return path;
}

当您从图库中选择图片时：

ChoosePhoto();
...
 protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
    base.OnActivityResult(requestCode, resultCode, data);
    if (requestCode == 0)
    {
        var uri = data.Data;
        var path = GetPathToImage(uri);
        System.Diagnostics.Debug.WriteLine("Image path == " + path );
        //My result is this ==> [0:] Image path == /storage/emulated/0/DCIM/Camera/IMG_20170813_223324.jpg
    }
 }

最重要的，当你使用这个方法的时候，也许你会遇到这样的问题：

Java.Lang.SecurityException：权限拒绝：从 pid=21975、uid=10417 读取 com.android.providers.media.MediaProvider uri content://media/external/images/media 需要 android.permission.READ_EXTERNAL_STORAGE 或 grantUriPermission()

当 API >= 23 时，在运行时请求权限，用户在应用程序运行时而不是在安装应用程序时向应用程序授予权限。你应该检查一下你是否有android.permission.READ_EXTERNAL_STORAGE权限，如果没有，则需要请求权限。