Android撕美女衣服小案例

package com.itheima74.syf;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Matrix;import android.graphics.Paint;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.MotionEvent;import android.view.View;import android.widget.ImageView;/** * 撕美女衣服 */public class MainActivity extends AppCompatActivity {    @Override    PRotected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        final ImageView iv = (ImageView) findViewById(R.id.iv);        // 创建原图        Bitmap bitmap_src = BitmapFactory.decodeResource(getResources(), R.drawable.pre19);        // 创建副本        final Bitmap bitmap_copy = Bitmap.createBitmap(bitmap_src.getWidth(), bitmap_src.getHeight(),                bitmap_src.getConfig());        Canvas canvas = new Canvas(bitmap_copy);        Paint paint = new Paint();        canvas.drawBitmap(bitmap_src, new Matrix(), paint);        // 将副本展示到iv上        iv.setImageBitmap(bitmap_copy);        // 设置iv的触摸事件,让所到之处变透明        iv.setOnTouchListener(new View.OnTouchListener() {            @Override            public boolean onTouch(View v, MotionEvent event) {                if (event.getAction() == MotionEvent.ACTION_MOVE) {                    for (int i = -30; i <= 30; i++) {                        for (int j = -30; j <= 30; j++) {                            if (Math.sqrt(i * i + j * j) < 30) {                                try {                                    bitmap_copy.setPixel((int) event.getX() + i, (int) event.getY() + j,                                            Color.TRANSPARENT);                                } catch (Exception e) {                                    // java.lang.IllegalArgumentException: x must be >= 0 不打印异常                                }                            }                        }                    }                    // 更新UI                    iv.setImageBitmap(bitmap_copy);                }                return true;            }        });    }}