package com.android.matrix; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Matrix; import android.graphics.drawable.BitmapDrawable; import android.os.Bundle; import android.view.ViewGroup.LayoutParams; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.ImageView.ScaleType; /**  * Android实现图片缩放与旋转。  * @author Administrator  *  */ public class MatixActivity extends Activity {     public void onCreate(Bundle icicle) {         super.onCreate(icicle);         setTitle("Android实现图片缩放与旋转。");         LinearLayout linLayout = new LinearLayout(this);         //加载需要操作的图片，这里是一张图片         Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),R.drawable.r);         //获取这个图片的宽和高         int width = bitmapOrg.getWidth();         int height = bitmapOrg.getHeight();         //定义预转换成的图片的宽度和高度         int newWidth = 200;         int newHeight = 200;         //计算缩放率，新尺寸除原始尺寸         float scaleWidth = ((float) newWidth) / width;         float scaleHeight = ((float) newHeight) / height;         // 创建操作图片用的matrix对象         Matrix matrix = new Matrix();         // 缩放图片动作         matrix.postScale(scaleWidth, scaleHeight);         //旋转图片 动作         matrix.postRotate(45);         // 创建新的图片         Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,         width, height, matrix, true);         //将上面创建的Bitmap转换成Drawable对象，使得其可以使用在ImageView, ImageButton中         BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);         //创建一个ImageView         ImageView imageView = new ImageView(this);         // 设置ImageView的图片为上面转换的图片         imageView.setImageDrawable(bmd);         //将图片居中显示         imageView.setScaleType(ScaleType.CENTER);         //将ImageView添加到布局模板中         linLayout.addView(imageView,         new LinearLayout.LayoutParams(         LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT         )         );         // 设置为本activity的模板         setContentView(linLayout);      }  }

package com.android.zooming; import android.view.View; import android.content.Context;  import android.graphics.Canvas;  import android.graphics.drawable.Drawable;  import android.view.KeyEvent;  public class Zoom extends View {      private Drawable image;       private int zoomControler=20;       public Zoom(Context context){           super(context);           image=context.getResources().getDrawable(R.drawable.x);           setFocusable(true);       }       @Override       protected void onDraw(Canvas canvas) {           // TODO Auto-generated method stub           super.onDraw(canvas);           //控制图像的宽度和高度          image.setBounds((getWidth()/2)-zoomControler, (getHeight()/2)-zoomControler, (getWidth()/2)+zoomControler, (getHeight()/2)+zoomControler);           image.draw(canvas);       }       @Override       public boolean onKeyDown(int keyCode, KeyEvent event) {               if(keyCode==KeyEvent.KEYCODE_DPAD_UP)//放大                      zoomControler+=10;               if(keyCode==KeyEvent.KEYCODE_DPAD_DOWN) //缩小                      zoomControler-=10;               if(zoomControler<10)                       zoomControler=10;               invalidate();               return true;       }  }