簡單的問題。 ListView顯示在Android Studio的預覽中,但是當我運行該應用程序時,它只是空白。ArrayAdapter沒有顯示在ListView中 - Android Studio
我有一個arrayadapter從數組中拉出一些數據,然後將它推入活動中的ListView。它應該顯示一個用戶可以在活動中滾動的菜單項列表。沒有這樣的運氣。
我試着玩XML文件的一些功能,但沒有得到解決,所以我在這裏。
這裏是我的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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.ericleeconklin.sleepnoise2.ListSounds"
tools:showIn="@layout/activity_list_sounds">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".ListActivity">
<ListView
android:id="@+id/mobile_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
</ListView>
</LinearLayout>
這裏是我的Java
package com.ericleeconklin.sleepnoise2;
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.app.Activity;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class ListSounds extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list_sounds);
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();
}
});
}
public class ListDisplay extends Activity {
// Array of strings...
String[] mobileArray = {"Waterfall","Fire","Fan","River","Heavy `Rain","Light Rain","Lawnmower","Restaurant"};`
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content_list_sounds);
ArrayAdapter adapter = new ArrayAdapter<String>(this, R.layout.activity_listview, mobileArray);
ListView listView = (ListView) findViewById(R.id.mobile_list);
listView.setAdapter(adapter);
}
}
}
只是儘量在第一的onCreate複製你的代碼,並刪除第二類..它沒用..否則做接口或調用你的主類List類,你的代碼是好的,但你打電話給內部類的列表活動,這就是爲什麼其空白 –
啊我明白了。我沒有注意到第二個創建。接得好。 –