import android.graphics.Color;import android.graphics.Matrix;import android.graphics.Paint;import android.view.Menu;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.widget.ImageView;public class MainActivity extends Activity {    private Bitmap srcBitmap;    private ImageView iv;    private Bitmap copyBitmap;    private Canvas canvas;    private Paint paint;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //[1]找到imageview  显示我们画的内容         iv = (ImageView) findViewById(R.id.iv);                //[2]把bg转换成bitmap         srcBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);        //[2.1]创建模板         copyBitmap = Bitmap.createBitmap(srcBitmap.getWidth(), srcBitmap.getHeight(), srcBitmap.getConfig());        //[2.2]以copybitmap为模板  创建一个画布         canvas = new Canvas(copyBitmap);        //[2.3]创建一个画笔         paint = new Paint();        //[2.4]开始作画         canvas.drawBitmap(srcBitmap, new Matrix(), paint);        //        canvas.drawLine(20, 20, 30, 50, paint);                //[3]把copybitmap显示到iv上         iv.setImageBitmap(copyBitmap);                //[4]给iv设置一个触摸事件         iv.setOnTouchListener(new OnTouchListener() {                        int startX = 0;            int startY = 0;            @Override            public boolean onTouch(View v, MotionEvent event) {                //[5]获取手指触摸的事件类型                 int action = event.getAction();                //[6]具体判断一下是什么事件类型                 switch (action) {                case MotionEvent.ACTION_DOWN: //按下                     //[7]获取手指按下坐标                     startX = (int) event.getX();                    startY= (int) event.getY();                    System.out.println("按下:"+startX+"---"+startY);                    break;                                    case MotionEvent.ACTION_MOVE://移动                     //[8]获取停止的坐标                      int stopX = (int) event.getX();                    int stopY = (int) event.getY();                                        System.out.println("移动:"+stopX+"---"+stopY);                                        //[9]画线                     canvas.drawLine(startX, startY, stopX, stopY, paint);                                        //[9.1]更新一下起点坐标                     startX = stopX;                    startY = stopY;                                        //[10]记得更新ui                     iv.setImageBitmap(copyBitmap);                                                            break;                                    case MotionEvent.ACTION_UP: //抬起;                    break;                }                return true;            }        });                            }    //点击按钮让画笔的颜色 变成红色     public void click1(View v) {        //设置画笔颜色        paint.setColor(Color.RED);    }            //让画笔颜色变粗    public void click2(View v) {        //设置画笔的宽度        paint.setStrokeWidth(15);            }        //保存大作     public void click3(View v) {        /**         * format 保存图片的格式          *          * quality 保存照片的质量         */        try {            File file = new File(Environment.getExternalStorageDirectory().getPath(),"dazuo.png");            FileOutputStream fos = new FileOutputStream(file);            copyBitmap.compress(CompressFormat.PNG, 100, fos);                        //发送一条sd卡挂载上来的广播 欺骗一下系统图库应用 说sd卡被挂载了 你去加载图片吧                        Intent intent = new Intent();            //设置action            intent.setAction(Intent.ACTION_MEDIA_MOUNTED);            //设置data             intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));                        //发送无序广播            sendBroadcast(intent);                        fos.close(); //关闭流                                } catch (Exception e) {            e.printStackTrace();        }                    }    }