使用Matrix平移图像

Dear 丶 2022-08-19 12:16 150阅读 0赞

1、布局文件

<?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/frameLayout1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >
       
    </FrameLayout>

2、MainActivity

public class MainActivity extends Activity {
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            FrameLayout ll = (FrameLayout)findViewById(R.id.frameLayout1);
            ll.addView(new MyView(this));
        }
        public class MyView extends View{
    		public MyView(Context context) {
    			super(context);
    		}
    		@Override
    		protected void onDraw(Canvas canvas) {
    			Paint paint = new Paint();//定义一个画笔
    			paint.setAntiAlias(true);//使用抗锯齿功能
    			Bitmap bitmap_bg = BitmapFactory.decodeResource(MainActivity.this.getResources(),
    					R.drawable.background);
    			canvas.drawBitmap(bitmap_bg, 0, 0, paint);//绘制背景
    			Bitmap bitmap_rabbit = BitmapFactory.decodeResource(MainActivity.this.getResources(),
    					R.drawable.rabbit);
    			canvas.drawBitmap(bitmap_rabbit, 0, 0, paint);//绘制原图
    			Matrix matrix = new Matrix();//创建一个Matrix的对象
    			matrix.setRotate(30);//将matrix旋转30°
    			matrix.postTranslate(100, 50);//将matrix平移到（100,50）的位置
    			canvas.drawBitmap(bitmap_rabbit, matrix, paint);//绘制图像并应用matrix的变换
    			super.onDraw(canvas);
    		}
        }
    }

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[Center]: /images/20220731/e791d98791b2446a93a5a96295a52c8b.png