Google Drive API implementation Xamarin Android

Question

我们的应用程序应该具有将应用程序文件保存到Google Drive的功能。当然，使用本地配置的帐户。

从安卓API，我试图找出一些线索。但安卓API与Xamarin的实现似乎对我来说非常困难

我已经从Xamarin组件安装了Google Play Services-Drive，但没有列出我们可以参考其流程和功能的示例。

Answer 1

基本步骤（有关详细信息，请参阅下面的链接）：

• 使用驱动器API和范围创建GoogleApiClient

• 尝试连接（登录）GoogleApiClient

• 第一次尝试连接时会失败，因为用户没有选择应该使用的谷歌帐户

  • 使用StartResolutionForResult处理此情况

• GoogleApiClient连接时

  • 请求驱动器内容（DriveContentsResult）将文件内容写入.

  • 获得结果后，将数据写入驱动器内容。

  • 设置文件的元数据

  • 使用驱动器内容创建基于驱动器的文件

注意：此示例假设您在设备/模拟器上安装了Google Drive，并且您已在启用Google Drive API的Google开发者API控制台中注册应用程序。

C#示例：

[Activity(Label = "DriveOpen", MainLauncher = true, Icon = "@mipmap/icon")]
public class MainActivity : Activity, GoogleApiClient.IConnectionCallbacks, IResultCallback, IDriveApiDriveContentsResult
{
    const string TAG = "GDriveExample";
    const int REQUEST_CODE_RESOLUTION = 3;
    GoogleApiClient _googleApiClient;
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.Main);
        Button button = FindViewById<Button>(Resource.Id.myButton);
        button.Click += delegate
        {
            if (_googleApiClient == null)
            {
                _googleApiClient = new GoogleApiClient.Builder(this)
                  .AddApi(DriveClass.API)
                  .AddScope(DriveClass.ScopeFile)
                  .AddConnectionCallbacks(this)
                  .AddOnConnectionFailedListener(onConnectionFailed)
                  .Build();
            }
            if (!_googleApiClient.IsConnected)
                _googleApiClient.Connect();
        };
    }
    protected void onConnectionFailed(ConnectionResult result)
    {
        Log.Info(TAG, "GoogleApiClient connection failed: " + result);
        if (!result.HasResolution)
        {
            GoogleApiAvailability.Instance.GetErrorDialog(this, result.ErrorCode, 0).Show();
            return;
        }
        try
        {
            result.StartResolutionForResult(this, REQUEST_CODE_RESOLUTION);
        }
        catch (IntentSender.SendIntentException e)
        {
            Log.Error(TAG, "Exception while starting resolution activity", e);
        }
    }
    public void OnConnected(Bundle connectionHint)
    {
        Log.Info(TAG, "Client connected.");
        DriveClass.DriveApi.NewDriveContents(_googleApiClient).SetResultCallback(this);
    }
    protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
    {
        base.OnActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE_RESOLUTION)
        {
            switch (resultCode)
            {
                case Result.Ok:
                    _googleApiClient.Connect();
                    break;
                case Result.Canceled:
                    Log.Error(TAG, "Unable to sign in, is app registered for Drive access in Google Dev Console?");
                    break;
                case Result.FirstUser:
                    Log.Error(TAG, "Unable to sign in: RESULT_FIRST_USER");
                    break;
                default:
                    Log.Error(TAG, "Should never be here: " + resultCode);
                    return;
            }
        }
    }
    void IResultCallback.OnResult(Java.Lang.Object result)
    {
        var contentResults = (result).JavaCast<IDriveApiDriveContentsResult>();
        if (!contentResults.Status.IsSuccess) // handle the error
            return;
        Task.Run(() =>
        {
            var writer = new OutputStreamWriter(contentResults.DriveContents.OutputStream);
            writer.Write("Stack Overflow");
            writer.Close();
            MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
                   .SetTitle("New Text File")
                   .SetMimeType("text/plain")
                   .Build();
            DriveClass.DriveApi
                      .GetRootFolder(_googleApiClient)
                      .CreateFile(_googleApiClient, changeSet, contentResults.DriveContents);
        });
    }
    public void OnConnectionSuspended(int cause)
    {
        throw new NotImplementedException();
    }
    public IDriveContents DriveContents
    {
        get
        {
            throw new NotImplementedException();
        }
    }
    public Statuses Status
    {
        get
        {
            throw new NotImplementedException();
        }
    }
}

参考编号：https://developers.google.com/drive/android/create-file