问题描述

我正在使用 Xamarin Forms 在 Android 中开发 2 个应用程序 A 和 B &iOS 和 B 需要从 A 获取一些数据(单向通信).以下是注意事项:

I am using Xamarin Forms to develop 2 applications A and B in Android & iOS, and B would need to fetch some data from A (1 way communication). Following are the points to note:

• 我不想从 A 打开 B(无法使用 url 方案)
• 我已将 android:sharedUserId 设置为相同
• 我尝试过 Xamarin.Auth，但它不会在应用之间共享数据
• 我试过 Xam.Plugins.Settings Nuget 插件，但它没有提供接口来传递 A 的包 ID，同时从 B 获取共享首选项

• I don't want to open B from A (No url scheme possible)
• I have made android:sharedUserId same for both
• I tried Xamarin.Auth, but it doesn't share data between apps
• I tried Xam.Plugins.Settings Nuget plugin, but it doesn't provide interface to pass package Id of A while fetching the Shared Preferences from B

我读到可以使用相同的组 ID 在 iOS 中共享数据.除了共享 SQLite db，还有什么方法可以在 Android 中共享数据?

I read that it is possible to share data in iOS using same Group Id. Is there any way to share data in Android apart from sharing SQLite db?

推荐答案

是的，还有其他方法可以实现目标.

• ContentProvider:只需要内容提供者如果您需要在多个应用程序之间共享数据

• ContentProvider: A content provider is only required if you need to share data between multiple applications

使用内容共享构建应用程序:有一些教程，你可以参考.

Building Apps with Content Sharing: There are some tutorial which you can refer to.

我已将两者的 android:sharedUserId 设为相同

I have made android:sharedUserId same for both

如果 A 和 B 的 sharedUserId 相同，则表示 A 和 B 将运行在同一个 Sandbox 中.

If both of A and B have the same sharedUserId, it means that A and B will run in the same Sandbox.

所以您的 A 和 B 可以访问彼此的包资源"；(如项目中的 Resources 文件夹或 Raw 文件夹)和文件(如路径:/data/data/your package name/file name)

So your A and B can access each other's "Package Resources" (like Resources folder or Raw folder in your project) and files (like the paths:/data/data/your package name/file name)

基于你制作的相同sharedUserId，我建议你按照以下步骤在A和B之间共享数据.

Base on the same sharedUserId which you have made, I suggest you follow below steps to share data between A and B.

我假设您要共享的数据是应用程序 A 中的 123".

I assume the data you want to share is "123" in applicaton A.

1)在应用程序A中，将数据写入路径为/data/data/your package name/file name的文件.该路径不需要任何权限，因为它属于内部存储:

  1) In application A, write the data to the file which path is /data/data/your package name/file name. This path doesn't need any permission, because it belongs to internal storage:

namespace ShareA
{
    [Activity(Label = "ShareA", MainLauncher = true)]
    public class MainActivity : Activity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);
            WriteSettings(this, "123");
        }

        private void WriteSettings(MainActivity context, string data)
        {
            try
            {
                using (var writer = new StreamWriter(
              OpenFileOutput("settings.dat", Android.Content.FileCreationMode.Private)))
                    writer.Write(data);

                Toast.MakeText(context, "Settings saved", ToastLength.Short).Show();
            }
            catch (Exception e)
            {
                Android.Util.Log.Error("lv",e.Message);
                Toast.MakeText(context, "Settings not saved", ToastLength.Short).Show();
            }

        }
    }
}

2) 在应用程序 B 中，从文件中读取数据:

  2) In application B, read the data from the file:

namespace ShareB
{
    [Activity(Label = "ShareB", MainLauncher = true)]
    public class MainActivity : Activity
    {
        TextView textView;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);
            textView = this.FindViewById<TextView>(Resource.Id.textView1);

            try
            {
                //get A's context
                Context ctx = this.CreatePackageContext(
                        "ShareA.ShareA", Android.Content.PackageContextFlags.IgnoreSecurity);
                //Read data
                string msg = ReadSettings(ctx);
                textView.Text= msg;
                Toast.MakeText(this, "DealFile2 Settings read" + msg, ToastLength.Short).Show();
                //Or you can change the data from B
                WriteSettings(ctx, "deal file2 write");
            }
            catch (PackageManager.NameNotFoundException e)
            {
                // TODO Auto-generated catch block
                Android.Util.Log.Error("lv", e.Message);
            }
        }

        private string ReadSettings(Context context)
        {
            try
            {   // context is from A
                using (var reader = new StreamReader(context.OpenFileInput("settings.dat")))
                {
                    return reader.ReadToEnd();
                }
            }
            catch
            {
                return "";
            }
        }

        private void WriteSettings(Context context, string data)
        {
            try
            {   // context is from A
                using (var writer = new StreamWriter(
              context.OpenFileOutput("settings.dat", Android.Content.FileCreationMode.Private)))
                    writer.Write(data);

                Toast.MakeText(context, "Settings saved", ToastLength.Short).Show();
            }
            catch (Exception e)
            {
                Android.Util.Log.Error("lv", e.Message);
                Toast.MakeText(context, "Settings not saved", ToastLength.Short).Show();
            }
        }
    }
}

注意:

以上代码基于A和B都具有相同的android:sharedUserId.

这篇关于在 Xamarin Forms 中的应用之间共享数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！