自定义控件(实现小飞机)

1.效果图:按A就往左移动，按W就往上移动，按S就往下移动，按D往右移动

2.planeView.java

package com.example.app4;

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

/**
 * Created by Administrator on 2018/5/16.
 */
public class palneView extends View {
    private Bitmap plane;
    public float currentX;
    public float currentY;

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

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint = new Paint();
        canvas.drawBitmap(plane,currentX,currentY,paint);
    }
}

3.MainActivity.java

package com.example.app4;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.KeyEvent;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends AppCompatActivity {
    public palneView pv;
    private int speed=10;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //去窗口标题
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        //全屏
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        pv= new palneView(MainActivity.this);
        setContentView(pv);
        DisplayMetrics metrics = new DisplayMetrics();

        //初始位置
        pv.currentX=metrics.widthPixels/2;
        pv.currentY=metrics.heightPixels/2;

        pv.setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                switch (event.getKeyCode()){
                    case KeyEvent.KEYCODE_W:
                        pv.currentY-=speed;
                        break;
                    case KeyEvent.KEYCODE_S:
                        pv.currentY+=speed;
                        break;
                    case KeyEvent.KEYCODE_A:
                        pv.currentX-=speed;
                        break;
                    case KeyEvent.KEYCODE_D:
                        pv.currentX+=speed;
                        break;

                }
                pv.invalidate();
                return true;
            }
        });
    }
}