25.Android之图像的平移、旋转及缩放学习

 1     //线程处理
 2     public void run() {
 3         while (!Thread.currentThread().isInterrupted()) {
 4             try {
 5                 Thread.sleep(100);
 6             }
 7             catch (InterruptedException e) {
 8                 Thread.currentThread().interrupt();
 9             }            
10             postInvalidate();                //使用postInvalidate可以直接在线程中更新界面
11         }
12     }

  1 package com.example.matrixdemo;
  2 
  3 import android.content.Context;
  4 import android.graphics.Bitmap;
  5 import android.graphics.Canvas;
  6 import android.graphics.Color;
  7 import android.graphics.Matrix;
  8 import android.graphics.drawable.BitmapDrawable;
  9 import android.view.KeyEvent;
 10 import android.view.View;
 11 
 12 
 13 public class MyView extends View implements Runnable {
 14 
 15     Bitmap mBitmap = null;                    //图像对象
 16     Matrix mMatrix = new Matrix();  //Matrix对象
 17     
 18     int mBitmapToLeft = 0;                      //图像距离屏幕左边界的距离
 19     int mBitmapToTop = 0;                      //图像距离屏幕顶端的距离
 20     
 21     float mAngle = 0.0f;                             //旋转角度
 22     float mScale = 1.0f;                              //缩放倍数
 23     
 24     public MyView(Context context) {
 25         super(context);
 26             
 27         mBitmap = ((BitmapDrawable) getResources().getDrawable
 28                 (R.drawable.kobe)).getBitmap();          // 从资源文件中装载图片
 29         
 30         new Thread(this).start();             //开启线程
 31     }
 32 
 33     public void onDraw(Canvas canvas) {
 34         super.onDraw(canvas);
 35         
 36         canvas.drawColor(Color.GRAY);                         //设置画布底色为灰色
 37         
 38         mMatrix.reset();                                                       //重置Matrix
 39         mMatrix.setRotate(mAngle);                             //设置旋转的角度
 40         mMatrix.postScale(mScale, mScale);            //设置缩放的倍数
 41         
 42         //构建经过处理的新的Bitmap
 43         Bitmap mBitmapRotate = Bitmap.createBitmap(mBitmap, 0, 0, 
 44                 mBitmap.getWidth(), mBitmap.getHeight(), mMatrix, true);
 45         
 46         MyView.drawImage(canvas, mBitmapRotate, mBitmapToLeft, mBitmapToTop);        
 47     }
 48     
 49     // 按键按下事件
 50     public boolean onKeyDown(int keyCode, KeyEvent event) {
 51         switch (keyCode) {                                              //处理平移
 52         case KeyEvent.KEYCODE_DPAD_UP:             //上方向键:上移
 53             if (mBitmapToTop > 0){
 54                 mBitmapToTop--;
 55             }
 56             break;
 57         case KeyEvent.KEYCODE_DPAD_DOWN:     //下方向键:下移
 58             if ((mBitmapToTop + mBitmap.getHeight()) < 800) {
 59                 mBitmapToTop++;
 60             }
 61             break;
 62         case KeyEvent.KEYCODE_DPAD_LEFT:        //左方向键:左移
 63             if (mBitmapToLeft > 0) {
 64                 mBitmapToLeft--;
 65             }
 66             break;
 67         case KeyEvent.KEYCODE_DPAD_RIGHT:      //右方向键:右移
 68             if ((mBitmapToLeft + mBitmap.getWidth()) < 480) {
 69                 mBitmapToLeft++;
 70             }
 71             break;
 72         }
 73         
 74         switch (keyCode) {                                        //处理旋转事件                    
 75         case KeyEvent.KEYCODE_MENU:              //MENU键:顺时针旋转
 76             mAngle--;
 77             break;
 78         case KeyEvent.KEYCODE_BACK:                //BACK键:逆时针旋转
 79             mAngle++;
 80             break;
 81         }
 82         
 83         switch (keyCode) {                                                      //处理缩放事件
 84         case KeyEvent.KEYCODE_VOLUME_DOWN:        //音量减键:缩小
 85             if (mScale > 0.5) {
 86                 mScale -= 0.2;
 87             }
 88             break;
 89         case KeyEvent.KEYCODE_VOLUME_UP:                //音量加键:放大
 90             if (mScale < 1.8) { 
 91                 mScale += 0.2;
 92             }
 93             break;
 94         }
 95         return true;
 96     }    
 97 
 98     // 按键弹起事件
 99     public boolean onKeyUp(int keyCode, KeyEvent event) {
100         return false;
101     }
102         
103      // 线程处理
104     public void run() {
105         while (!Thread.currentThread().isInterrupted()) {
106             try {
107                 Thread.sleep(200);
108             }
109             catch (InterruptedException e) {
110                 Thread.currentThread().interrupt();
111             }            
112             postInvalidate();                //使用postInvalidate可以直接在线程中更新界面
113         }
114     }
115     
116     // 绘制Bitmap
117     public static void drawImage(Canvas canvas, Bitmap bitmap, int x, int y) {
118         canvas.drawBitmap(bitmap, x, y, null);
119     }
120 }