实训周五

用Android studio制作全民飞机大战的游戏菜单界面；先创建一个java类，然后继承类似于测试类的SurfaceView，在用接口SurfaceHolder.Callback，这样就继承了三个方法，能通过三个方法写；
总的来说就是用画笔在画布上画出这个界面

package com.example.fly.myapplication;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**
* Created by fly on 2017/5/24.
*/
public class GameSurfaceview extends SurfaceView implements SurfaceHolder.Callback {
private Canvas canvas;
private Paint paint;
private SurfaceHolder surfaceHolder;
public static int screenWidth;//手机屏幕的宽
public static int screenHeight;//手机屏幕的高

//Menu相关
private GameMenu gameMenu;
private Bitmap bmpMenuBG;//菜单页面背景图片
private Bitmap bmpMenuLogo;//菜单页面Logo
private Bitmap bmpMenuButton;//菜单页面按钮
private Bitmap bmpbtBG;//菜单页面按钮背景

public GameSurfaceview(Context context) {
    super(context);
    surfaceHolder = this.getHolder();//初始化holder对象
    surfaceHolder.addCallback(this);
    paint=new Paint();
    paint.setAntiAlias(true);

}

@Override
public void surfaceCreated(SurfaceHolder holder) {

    screenWidth=this.getWidth();
    screenHeight=this.getHeight();

    initBitmap();


    new Thread(new Runnable() {
        @Override
        public void run() {
            myDraw();
        }


    }).start();
}


@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {

}

//绘图方法
private void myDraw() {
    canvas = surfaceHolder.lockCanvas();
    //调用GameMenu对象画游戏菜单页面
    gameMenu.draw(canvas,paint);

    if(canvas!=null){
        surfaceHolder.unlockCanvasAndPost(canvas);
    }
}

/**
 * 初始化图片方法
 */
private void initBitmap() {
    //把图片转化成Bitmap
    bmpMenuBG = BitmapFactory.decodeResource(this.getResources(), R.drawable.mainmenu);
    bmpMenuLogo = BitmapFactory.decodeResource(this.getResources(), R.drawable.logo);
    bmpMenuButton = BitmapFactory.decodeResource(this.getResources(), R.drawable.starttext);
    bmpbtBG = BitmapFactory.decodeResource(this.getResources(), R.drawable.menustart);
    //初始化对象
    gameMenu = new GameMenu(bmpMenuBG, bmpMenuLogo, bmpbtBG, bmpMenuButton);
}

}

这个类写的是一些背景用的方法以及图片所放的坐标位置，让整个界面变得整齐

package com.example.fly.myapplication;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;

/**
* Created by fly on 2017/5/24.
*/

public class GameMenu {
private Bitmap bmpMenuBG;//菜单页面背景图片
private Bitmap bmpMenuLogo;//菜单页面Logo
private Bitmap bmpMenuButton;//菜单页面按钮
private Bitmap bmpbtBG;//菜单页面按钮背景
private Rect rect;

public GameMenu(Bitmap bmpMenuBG, Bitmap bmpMenuLogo, Bitmap bmpMenuButton, Bitmap bmpbtBG) {
    this.bmpMenuBG = bmpMenuBG;
    this.bmpMenuLogo = bmpMenuLogo;
    this.bmpMenuButton = bmpMenuButton;
    this.bmpbtBG = bmpbtBG;

    rect=new Rect
(0,GameSurfaceview.screenHeight/3,GameSurfaceview.screenWidth,GameSurfaceview.screenHeight/3+GameSurfaceview.screenHeight/5);
}//GameSurfaceview.screenHeight是调用这个高度；GameSurfaceview.screenWidth是调用这个宽度，四个变量，分别是左上角x，y坐标和右下角x，y坐标

public void draw(Canvas canvas, Paint paint) {
    canvas.drawBitmap(bmpMenuBG, 0, 0, paint);

    canvas.drawBitmap(bmpMenuLogo, null, rect, paint);

    int x=GameSurfaceview.screenWidth/2-bmpMenuButton.getWidth()/2;
    int y=GameSurfaceview.screenHeight/3*2;
    canvas.drawBitmap(bmpMenuButton, x, y, paint);

    int m=GameSurfaceview.screenWidth/2-bmpbtBG.getWidth()/2;
    int n=GameSurfaceview.screenHeight/3*2;
    canvas.drawBitmap(bmpbtBG, m, n, paint);
}

}