Android学习之控制飞机移动

效果图：

PlaneView.java

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

public class PlaneView extends View{
    public float currentX,currentY;
    Bitmap plane;
    //创建画笔
    Paint p = new Paint();

    public PlaneView(Context context) {
        super(context);
        plane = BitmapFactory.decodeResource(context.getResources(), R.drawable.plane);
        setFocusable(true);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawBitmap(plane, currentX, currentY, p);
    }
}

PlaneGame.java

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.view.WindowManager;

public class MainActivity extends Activity{
    //定义飞机的移动速度
    private int speed = 10;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //全屏显示，不显示系统的状态栏
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        /*
        *创建PlaneView组件
        *这里可以传入this因为context是activity的父类
        */
        final PlaneView planeView = new PlaneView(this);
        setContentView(planeView);
        //获取窗口管理器
        WindowManager windowManager = getWindowManager();
        Display display = windowManager.getDefaultDisplay();
        DisplayMetrics displayMetrics = new DisplayMetrics();
        //获取屏幕宽和高
        display.getMetrics(displayMetrics);
        //设置飞机的初始位置
        planeView.currentX = displayMetrics.widthPixels / 2;
        planeView.currentY = displayMetrics.heightPixels - 40;
        //为draw组件键盘事件绑定监听器  
        planeView.setOnKeyListener(new OnKeyListener() {

            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                //获取由哪个键触发的事件
                switch (event.getKeyCode()) {
                //控制飞机下上左右移
                case KeyEvent.KEYCODE_S:
                    planeView.currentY += speed;
                    break;
                case KeyEvent.KEYCODE_W:
                    planeView.currentY -= speed;
                    break;
                case KeyEvent.KEYCODE_A:
                    planeView.currentX -= speed;
                    break;
                case KeyEvent.KEYCODE_D:
                    planeView.currentX += speed;
                    break;
                default:
                    break;
                }
                //通知planeView组件重绘
                planeView.invalidate();
                return true;
            }
        });     
    }
}

这里飞机的上下左右移动方向的加减参照：

飞机图标：