Android中View跟随手指移动效果

package com.example.plane;import Android.app.Activity;import android.os.Bundle;import android.util.DisplayMetrics;import android.view.Display;import android.view.KeyEvent;import android.view.Menu;import android.view.MenuItem;import android.view.MotionEvent;import android.view.View;import android.view.View.OnKeyListener;import android.view.View.OnTouchListener;import android.view.Window;import android.view.WindowManager;public class MainActivity extends Activity {private int speed = 10;private MyPlane plane;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);plane = new MyPlane(this);setContentView(plane);// plane.setBackgroundResource(R.drawable.ic_launcher);WindowManager manager = getWindowManager();Display display = manager.getDefaultDisplay();DisplayMetrics metrics = new DisplayMetrics();display.getMetrics(metrics);plane.currentX = metrics.widthPixels / 2;plane.currentY = metrics.heightPixels / 2;}@Overridepublic boolean onTouchEvent(MotionEvent event) {/*float x = 0;float y = 0;switch (event.getAction()) {case MotionEvent.ACTION_DOWN:x = event.getX();y = event.getY();break;case MotionEvent.ACTION_MOVE:x = event.getX();y = event.getY();break;case MotionEvent.ACTION_UP:x = event.getX();y = event.getY();break;}*/plane.currentX=event.getX();plane.currentY=event.getY();plane.invalidate();return super.onTouchEvent(event);}}package com.example.plane;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 MyPlane extends View {Bitmap plane;public float currentX;public float currentY;public MyPlane(Context context) {super(context);plane = BitmapFactory.decodeResource(context.getResources(),R.drawable.ic_launcher);setFocusable(true);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);Paint p = new Paint();canvas.drawBitmap(plane, currentX, currentY, p);}}