アクションバーの削除と表示

2019ユニコーン企業重く募集エンジニアのPythonの標準>>>

activity_main.xml：

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".ActionBarHiddenActivity" >

    <Button android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="隐藏动作栏"
        android:textColor="@android:color/white"
        android:textSize="20dp"/>

</RelativeLayout>

ActionBarHiddenActivity.java：

package com.example.demoactionbar;

import android.app.ActionBar;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class ActionBarHiddenActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		final ActionBar bar = getActionBar();
		final Button button = (Button)findViewById(R.id.button);
		button.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View view) {
				if(bar.isShowing()){
					bar.hide();
					button.setText("显示动作栏");
				}else{
					bar.show();
					button.setText("隐藏动作栏");
				}

				
			}
		});
	}

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

}

AndroidManifest.xmlを：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.demoactionbar"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.demoactionbar.ActionBarHiddenActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

ます。https：//my.oschina.net/u/2552902/blog/543928で再現