libgdx退出对话框

package com.fxb.newtest;

import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.InputAdapter;
import com.badlogic.gdx.InputMultiplexer;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL10;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.Dialog;
import com.badlogic.gdx.scenes.scene2d.ui.Skin;
import com.badlogic.gdx.scenes.scene2d.ui.Button.ButtonStyle;
import com.badlogic.gdx.scenes.scene2d.ui.Label.LabelStyle;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton.TextButtonStyle;
import com.badlogic.gdx.scenes.scene2d.ui.Window.WindowStyle;
import com.badlogic.gdx.scenes.scene2d.utils.Align;
import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;

public class Lib005_CancelKey extends InputAdapter implements ApplicationListener{

    Stage stage;
    Skin skin;
    Dialog dialog1, dialog2;

    @Override
    public void create() {
        // TODO Auto-generated method stub

        CreateSkin();

        stage = new Stage();
        InputMultiplexer multiplexer = new InputMultiplexer();
        multiplexer.addProcessor( stage );
        multiplexer.addProcessor( this );
        Gdx.input.setInputProcessor( multiplexer );
        Gdx.input.setCatchBackKey( true );
        Gdx.input.setCatchMenuKey( true );

        TextButton textbutton1 = new TextButton( "Menu", skin );
        TextButton textbutton2 = new TextButton( "Exit", skin );

        textbutton1.addListener( new ChangeListener(){
            @Override
            public void changed(ChangeEvent event, Actor actor) {
                // TODO Auto-generated method stub
                dialog1.show(stage);
            }
        });
        textbutton2.addListener( new ChangeListener(){
            @Override
            public void changed(ChangeEvent event, Actor actor) {
                // TODO Auto-generated method stub
                dialog2.show(stage);
            }
        });
        textbutton1.setPosition( 100, 100 );
        textbutton2.setPosition( 200, 100 );

        stage.addActor( textbutton1 );
        stage.addActor( textbutton2 );

    }

    private void CreateSkin(){
        skin = new Skin();
        Pixmap pixmap = new Pixmap( 1, 1, Format.RGBA8888 );
        pixmap.setColor( Color.GRAY );
        pixmap.fill();
        //draw1 = new TextureRegionDrawable(  );
        //texture = new Texture( pixmap );
        skin.add( "gray", new Texture(pixmap) );

        pixmap.setColor( Color.LIGHT_GRAY );
        pixmap.fill();
        skin.add( "light_gray", new Texture(pixmap) );

        BitmapFont font = new BitmapFont();
        WindowStyle windowStyle = new WindowStyle( font, Color.GREEN, skin.getDrawable( "light_gray" ) );

        LabelStyle labelStyle = new LabelStyle( font, Color.RED );
        ButtonStyle buttonStyle = new ButtonStyle( skin.getDrawable("gray"), skin.getDrawable("light_gray"), null );
        TextButtonStyle textbuttonStyle = new TextButtonStyle( skin.getDrawable("gray"), skin.getDrawable("light_gray"), null, font );
        skin.add( "default", buttonStyle );
        skin.add( "default", textbuttonStyle );
        skin.add( "default", windowStyle );
        skin.add( "default", labelStyle );

        dialog1 = new Dialog( "Menu", skin, "default" ){
            @Override
            protected void result(Object object) {
                // TODO Auto-generated method stub
                //System.out.println( "Chosen" + object );
                if( object.toString().equals( "true" ) ){
                    System.out.println( "Yes" );
                    Gdx.app.exit();
                }else{
                    System.out.println( "No" );
                }
            }};
        dialog1.text("\nMenu").button("Yes", true).button("No",false).key(Keys.ENTER, true).key(Keys.ESCAPE,false);
        dialog1.setTitleAlignment( Align.top );

        dialog2 = new Dialog( "Exit", skin, "default" ){
            @Override
            protected void result(Object object) {
                // TODO Auto-generated method stub
                //System.out.println( "Chosen" + object );
                if( object.toString().equals( "true" ) ){
                    System.out.println( "Yes" );
                    Gdx.app.exit();
                }else{
                    System.out.println( "No" );
                }
            }};
        dialog2.text("\nDo you want to exit?").button("Yes", true).button("No",false).key(Keys.ENTER, true).key(Keys.ESCAPE,false);
        dialog2.setTitleAlignment( Align.top );

    }

    @Override
    public void resize(int width, int height) {
        // TODO Auto-generated method stub

    }

    @Override
    public void render() {
        // TODO Auto-generated method stub
        Gdx.gl.glClearColor( 1, 1, 1, 1 );
        Gdx.gl.glClear( GL10.GL_COLOR_BUFFER_BIT );

        stage.act();
        stage.draw();
    }

    @Override
    public void pause() {
        // TODO Auto-generated method stub

    }

    @Override
    public void resume() {
        // TODO Auto-generated method stub

    }

    @Override
    public void dispose() {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean keyDown(int keycode) {
        // TODO Auto-generated method stub

        if( keycode == Input.Keys.BACK ){
            Gdx.app.log( "back", "" );
            dialog2.show(stage);
        }
        if( keycode == Input.Keys.MENU ){
            Gdx.app.log( "menu", "" );
            dialog1.show(stage);
        }

        return false;
    }

}

libgdx开发中返回键（cancel）和菜单键（menu）的使用。

开始时需要设置Gdx.input.enableCancelKey或者Gdx.input.enableMenuKey，然后捕获到相应事件时添加事件响应即可。