Android经典设计例程源码-Matrix.rar

package tjuci.edu.dl; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.drawable.BitmapDrawable; import android.os.Bundle; import android.view.KeyEvent; import android.view.View; public class MatrixActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(new MyDraw(this)); } class MyDraw extends View { Matrix m; // 图片的位相 Bitmap b; // 位相的宽和高 int width; int height; // 定义倾斜和缩放 true:缩放 false:倾斜 boolean isScale; // 等比例缩放 float scale = 1.0f; // 倾斜 float kx = 0.0f; public MyDraw(Context context) { super(context); m = new Matrix(); b = ((BitmapDrawable) this.getResources().getDrawable( R.drawable.q11)).getBitmap(); width = b.getWidth(); height = b.getHeight(); // 使当前视图获得焦点 this.setFocusable(true); } @Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub super.onDraw(canvas); m.reset(); if (isScale) { // 缩放 m.setScale(scale, scale); } else { // 倾斜 m.setSkew(kx, 0); } Paint paint = new Paint(); Bitmap b2 = Bitmap.createBitmap(b, 0, 0, width, height, m, true); canvas.drawBitmap(b2, m, paint); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { // TODO Auto-generated method stub switch (keyCode) { case KeyEvent.KEYCODE_DPAD_LEFT: isScale = false; kx -= 1; postInvalidate(); break; case KeyEvent.KEYCODE_DPAD_RIGHT: isScale = false; kx += 1; postInvalidate(); break; case KeyEvent.KEYCODE_DPAD_UP: isScale = true; scale += 1; postInvalidate(); break; case KeyEvent.KEYCODE_DPAD_DOWN: isScale = true; scale -= 1; postInvalidate(); break; } return true; } } }