我如何使用System.IO使用ListView在xamarin.android上显示文件夹/文件？

Question

所以这是我问过的上一个问题的后续步骤Here

在遵循Jasons的建议之后，我做了一点点恢复，以使用System.IO来使用listview在android上显示文件夹。

我从Microsoft网站获得以下示例...

    class PublicListViews : ListActivity
{
    public string ListCreate(string path)
    {

        ListAdapter = new ArrayAdapter<string>(this, Resource.Layout.list_item, countries);

        ListView.TextFilterEnabled = true;

        ListView.ItemClick += delegate (object sender, AdapterView.ItemClickEventArgs args)
        {
            Toast.MakeText(Application, ((TextView)args.View).Text, ToastLength.Short).Show();
        };
        return path;
    }
}

根据我对这行的理解。...（这是Resource.Layout.list_item，国家/地区；将在android项目的resourses文件夹中使用list_item.xml，countrys是将要列出的国家的数组。

而且我还找到了以下代码来获取目录和文件...

        public static void ProcessDirectory(string targetDirectory)
    {
        // Process the list of files found in the directory.
        string[] fileEntries = Directory.GetFiles(targetDirectory);
        foreach (string fileName in fileEntries)
            ProcessFile(fileName);

        // Recurse into subdirectories of this directory.
        string[] subdirectoryEntries = Directory.GetDirectories(targetDirectory);
        foreach (string subdirectory in subdirectoryEntries)
            ProcessDirectory(subdirectory);
    }

    // Insert logic for processing found files here.
    public static void ProcessFile(string path)
    {
        Console.WriteLine("Processed file '{0}'.", path);
    }

有人可以帮助我实现使用ListAdaptor列出文件夹/文件以及如何通过MainPage.xaml进行调用吗？

Mark。

Answer 1

根据您的描述，我想您想从文件夹中获取文件，然后在xamarin.android中的ListView中显示这些文件路径？我说的对吗？

如果是的话，我创建一个简单的例子，您可以看一下：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" 
android:orientation="vertical">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content" 
    android:id="@+id/listView1"/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content" 
    android:text="get files" android:id="@+id/button1"/>
</LinearLayout>

 public class MainActivity : AppCompatActivity
{
    private ListView listview1;
    private Button button1;
    private List<string> files;

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        Xamarin.Essentials.Platform.Init(this, savedInstanceState);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.activity_main);

        listview1 = FindViewById<ListView>(Resource.Id.listView1);
        button1 = FindViewById<Button>(Resource.Id.button1);
        files = new List<string>();
        button1.Click += delegate
          {
              getpermission();
              //var targetdic = global::Android.OS.Environment.ExternalStorageDirectory.Path + "/testfolder";
              var targetdic = Android.OS.Environment.ExternalStorageDirectory + Java.IO.File.Separator + "testfolder";
              if(Directory.Exists(targetdic))
              {
                  files = DirSearch(targetdic);

                  listview1.Adapter = new ArrayAdapter(this, Android.Resource.Layout.SimpleListItem1, files);

                  listview1.ItemClick += (s, e) =>
                  {
                      var t = files[e.Position];
                      Android.Widget.Toast.MakeText(this, t, Android.Widget.ToastLength.Long).Show();
                  };
              }

          };
    }

    private void getpermission()
    {
        if (ActivityCompat.CheckSelfPermission(this, Android.Manifest.Permission.ReadExternalStorage) != Android.Content.PM.Permission.Granted)
        {

            ActivityCompat.RequestPermissions(this, new string[] { Android.Manifest.Permission.ReadExternalStorage }, 1);
            return;
        }
    }

    private List<String> DirSearch(string sDir)
    {
        List<string> folders = new List<string>();
        try
        {
            foreach (string f in Directory.GetFiles(sDir))
            {
                folders.Add(f);
            }
            foreach (string d in Directory.GetDirectories(sDir))
            {
                folders.AddRange(DirSearch(d));
            }
        }
        catch (System.Exception excpt)
        {

        }

        return folders;
    }
    public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
    {
        Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);

        base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}

请不要忘记请求READ_EXTERNAL_STORAGE许可