Question

我想要的是获得尽可能多的文本视图（listrows）项目数量。循环的手段。请帮帮我CODERS。我只得到最后一项，所以我＆＃34;硬编码＆＃34;它

公共类AllNotes扩展了Activity {

Button button;
TextView textview;

// trial copy code from other from net
private ListView mainListView ;
private ArrayAdapter<String> listAdapter ;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.all_notes);

    String path = Environment.getExternalStorageDirectory().toString()+ "/" + FirstOneAct.foldername;
    Log.d("Files", "Path: " + path);
    File f = new File(path);        
    File file[] = f.listFiles();
    Log.d("Files", "" + file.length);
    Toast.makeText(this, "" + file.length ,Toast.LENGTH_SHORT).show();

    for (int i=0; i < file.length; i++)
    {

     // trial copy code from other from net
        // Find the ListView resource. 
        mainListView = (ListView) findViewById( R.id.mainListView );

        ArrayList<String> planetList = new ArrayList<String>();     
        // Create ArrayAdapter using the planet list.
        listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);

        listAdapter.add(file[0].getName());
        listAdapter.add(file[1].getName());
        listAdapter.add(file[2].getName());
        listAdapter.add(file[3].getName());
        listAdapter.add(file[4].getName());

     // Set the ArrayAdapter as the ListView's adapter.
        mainListView.setAdapter( listAdapter ); 

        Log.d("Files", "FileName:" + file[i].getName());
        Toast.makeText(getApplicationContext(), file[i].getName(),Toast.LENGTH_LONG).show();
    }

    /*// Set the ArrayAdapter as the ListView's adapter.
    mainListView.setAdapter( listAdapter ); */     
  }
}

Answer 1

也许问题出在for循环中，你总是创建新的Listview和arrayadapter

尝试使用以下

String path = Environment.getExternalStorageDirectory().toString()+ "/" + FirstOneAct.foldername;
        Log.d("Files", "Path: " + path);
        File f = new File(path);        
        File file[] = f.listFiles();
        Log.d("Files", "" + file.length);
        Toast.makeText(this, "" + file.length ,Toast.LENGTH_SHORT).show();
        ListView mainListView = (ListView) findViewById( R.id.mainListView );
        ArrayList<String> planetList = new ArrayList<String>(); 


        for (int i=0; i < file.length; i++)
        {   
            planetList.add(file[i].getName());
        }
        // Create ArrayAdapter using the planet list.
        listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);
        // Set the ArrayAdapter as the ListView's adapter.
        mainListView.setAdapter( listAdapter ); 

        Log.d("Files", "FileNames:" + planetList);
        Toast.makeText(getApplicationContext(), planetList.toString(),Toast.LENGTH_LONG).show();

Answer 2

正如Der Golem所说，只需使用file [i]但是你还需要在for循环之前声明listAdapter，否则每次遍历循环时它都会重新赋值！

这是一本可以帮助您的快速指南：

    mainListView = (ListView) findViewById( R.id.mainListView );

    ArrayList<String> planetList = new ArrayList<String>();     
    // Create ArrayAdapter using the planet list.
    listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);

    for (int i=0; i < file.length; i++)
    {
       listAdapter.add(file[i].getName());
    }

 // Set the ArrayAdapter as the ListView's adapter.
    mainListView.setAdapter( listAdapter ); 

    Log.d("Files", "FileName:" + file[i].getName());
    Toast.makeText(getApplicationContext(), file[i].getName(),Toast.LENGTH_LONG).show();

希望这会有所帮助。

Answer 3

Button button;
TextView textview;

// trial copy code from other from net
private ListView mainListView ;
private ArrayAdapter<String> listAdapter ;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.all_notes);

    String path = Environment.getExternalStorageDirectory().toString()+ "/" + FirstOneAct.foldername;

    File f = new File(path);        
    File file[] = f.listFiles();

    ArrayList<String> planetList = new ArrayList<String>();     

    for (int i=0; i < file.length; i++) {
        planetList.add(file[i].getName());
    }

    // Create ArrayAdapter using the planet list.
    listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);

    // Find the ListView resource. 
    mainListView = (ListView) findViewById( R.id.mainListView );

    // Set the ArrayAdapter as the ListView's adapter.
    mainListView.setAdapter( listAdapter ); 

    }
}

需要纠正FOR循环。 Android系统。需要循环才能为动态项目工作

3 个答案: