Question

我遇到ListView问题。它没有显示。我知道这是一个常见的问题，但我是Android的新手。在大多数示例中，问题通过layout_bellow属性解决，但我没有任何其他控件。这是我的XML代码：

这是我的activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.gkmicro.trrrrrrrrrrrrrr.MainActivity"
    tools:showIn="@layout/activity_main">

    <ListView
        android:id="@+id/myListView"        
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />
</RelativeLayout>

这是我的MainActivity.java：

package com.gkmicro.trrrrrrrrrrrrrr;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

Answer 1

更改ListView以使用父RelativeLayout

的所有宽度和高度

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.gkmicro.trrrrrrrrrrrrrr.MainActivity"
    tools:showIn="@layout/activity_main">

    <ListView
        android:id="@+id/myListView"        
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

按照推荐的方式@Erik Jhordan Rey Caffrey使用RecyclerView

编辑：如果您有任何问题here is a good sample在RelativeLayout中实现简单的listView

希望这有帮助！

Answer 2

由于ListView为android:layout_alignParentBottom="true"，因此android:layout_height="wrap_content"

所以让ListView像这样

<ListView
    android:id="@+id/myListView"        
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
     />

Android ListView不显示任何内容（相对布局）

2 个答案: