1、前言

腾讯的手机管家，用过这个App的人都应该知道桌面的火箭一键加速这个功能，研究一下这个小火箭是怎么做出来的。先来了解一下小火箭有神马动作，首先在没有触碰它时，就是一个电源的显示或是一个图标依附在屏幕的两侧，点击变成小火箭，可以跟随拖动，当没有放到指定位置就在次回去屏幕两侧。当放到了指定位置就会出现一个火箭发射的动画。

2、完成的效果图

3、简单设计过程

自定义一个View完成火箭的拖动、显示，然后拖动到指定位置后就回调一个接口播放火箭发射动画。自定义View里面的关键就是动态的改变matrix，以达到火箭移动的效果

4、核心代码

自定义View的代码

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Point;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;public class Rocket extends View {private Bitmap bitmap;private Bitmap rocket;private Bitmap[] stand = {BitmapFactory.decodeResource(getResources(),R.drawable.desktop_bg_tips_1),BitmapFactory.decodeResource(getResources(),R.drawable.desktop_bg_tips_2),BitmapFactory.decodeResource(getResources(),R.drawable.desktop_bg_tips_3) };private Matrix matrix = new Matrix();private Paint paint = new Paint();private boolean isTouch = false;private Point point = new Point();private LocationChangeListener changeListener = null;private int screenW;private int screenH;private boolean isFly = false;public Rocket(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);System.out.println("init_2");}public Rocket(Context context, AttributeSet attrs) {super(context, attrs);System.out.println("init_3");bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.floating_desktop_bg_danger);rocket = BitmapFactory.decodeResource(getResources(),R.drawable.desktop_rocket_launch_1);screenW = ((Activity) context).getWindowManager().getDefaultDisplay().getWidth();screenH = ((Activity) context).getWindowManager().getDefaultDisplay().getHeight();System.out.println("blueberry_screenw=" + screenW);System.out.println("blueberry_screenH=" + screenH);}public Rocket(Context context) {super(context);System.out.println("init_1");}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);System.out.println("onDraw_1");System.out.println("isTouch=" + isTouch);if (!isTouch) {matrix.reset(); //重置matrixSystem.out.println("isFly=" + isFly);if (isFly) {if (changeListener != null)changeListener.onchange();} else {if (point.x < screenW / 2) {matrix.postTranslate(0, point.y);} else {matrix.postTranslate(screenW - bitmap.getWidth(), point.y);}canvas.drawBitmap(bitmap, matrix, paint);}} else {matrix.reset();int c = point.x % 2; //获取当前坐标的奇偶System.out.println("c="+c);matrix.postTranslate(screenW / 2 - stand[c].getWidth() / 2, screenH- stand[c].getHeight() - 100); //绘制云雾位置if (Math.abs(screenW / 2 - (point.x - rocket.getWidth() / 2)) < stand[c].getWidth() / 2&& Math.abs(screenH - stand[c].getHeight() - 100- (point.y - rocket.getHeight())) < stand[c].getHeight()) {canvas.drawBitmap(stand[2], matrix, paint);isFly = true;} else {//isFly = false;canvas.drawBitmap(stand[c], matrix, paint);}matrix.reset();matrix.postTranslate(point.x - rocket.getWidth() / 2, point.y- rocket.getHeight());  //火箭的位置canvas.drawBitmap(rocket, matrix, paint); //绘制火箭}}@Overridepublic boolean onTouchEvent(MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:System.out.println("ACTION_DOWN");System.out.println("event.getX() < screenW - bitmap.getWidth()="+(event.getX() < screenW - bitmap.getWidth()));System.out.println("event.getX() > bitmap.getWidth()="+(event.getX() > bitmap.getWidth()));if ((event.getX() < screenW - bitmap.getWidth() && event.getX() > bitmap.getWidth())|| Math.abs(point.y - event.getY()) > bitmap.getHeight()) {return false;}isTouch = true;break;case MotionEvent.ACTION_MOVE:System.out.println("ACTION_MOVE");point.x = (int) event.getX();point.y = (int) event.getY();break;case MotionEvent.ACTION_CANCEL:System.out.println("ACTION_CANCEL");isTouch = false;break;case MotionEvent.ACTION_UP:System.out.println("ACTION_UP");isTouch = false;break;}invalidate();return true;}public void reset() {isFly = false;point.y = screenH / 2;invalidate();}public void setOnChangeListener(LocationChangeListener changeListener) {this.changeListener = changeListener;}}

5、总结

这个UI制作的时候老是纠结于，在View里面播放动画，找了老半天没有找到解决方法，最后就把动画放到了外面回调一下，虽然大体的效果出来了，但个人觉得还是有

不完善的地方，比如发射动画不是很平滑，没有加入电量显示，没有控制边界，小火箭拉到屏幕外后就看不到控制的小圆点了。最后欢迎大家的讨论，和指点。

6. 下载源码地址

高仿QQ的手机管家的小火箭加速

7. 更多源码地址

游戏源码

http://blog.csdn.net/xiabing082/article/details/41863003

应用源码

http://blog.csdn.net/xiabing082/article/details/10189827