两点触控--画多边形

来源：互联网发布：理财入门知乎编辑：程序博客网时间：2024/06/11 20:57
public class MainActivity extends AppCompatActivity implements View.OnTouchListener{    ImageView image;    private static final String TAG = "TAG";    Canvas canvas;    Paint p;    Paint p1;    Path path;    Bitmap baseBitmap;    Bitmap bitmap;    Button refresh,ablum;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        init();        //刷新        refresh.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                refreshImage();            }        });        //从相册里获取图片        ablum.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {            }        });    }        private void init(){        image = (ImageView) findViewById(R.id.image01_main);        image.setOnTouchListener(this);        refresh = (Button) findViewById(R.id.btn01_main);        ablum = (Button) findViewById(R.id.btn02_main);        p = new Paint();        p.setColor(Color.RED);        p.setStrokeWidth(5);        p1 = new Paint();        p1.setColor(Color.GREEN);        p1.setStrokeWidth(5);        p1.setStyle(Paint.Style.STROKE);        path = new Path();    }    private void initCanvas(){//        if (baseBitmap==null){        //新建一个空的Bitmap            baseBitmap = Bitmap.createBitmap(image.getWidth(), image.getHeight(), Bitmap.Config.ARGB_8888);            bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.a2);            canvas = new Canvas(baseBitmap);            canvas.drawColor(Color.WHITE);            canvas.drawBitmap(bitmap,new Matrix(),p);//        }        image.setImageBitmap(baseBitmap);    }    float startX;    float startY;    float mstartX1;    float mstartY1;    @Override    public boolean onTouch(View v, MotionEvent event) {        Log.d(TAG, "onTouch: ");        initCanvas();        switch (event.getAction()&MotionEvent.ACTION_MASK){            case MotionEvent.ACTION_DOWN://按下第一个手指                startX = event.getX();                startY=event.getY();                mstartY1=0;                mstartX1=0;                Log.d(TAG, "按下第一个手指MotionEvent.ACTION_DOWN: ");                Log.d(TAG, "按下第一个手指d的坐标: x "+startX+"   y  : "+startY);                path.moveTo(startX,startY);                break;            case MotionEvent.ACTION_POINTER_DOWN:                float startX1 = event.getX(0);                float startY1=event.getY(0);                float startX2 = event.getX(1);                float startY2=event.getY(1);                Log.d(TAG, "按下第二个手指MotionEvent.ACTION_POINTER_DOWN: ");                Log.d(TAG, "按下第二个手指d的坐标: startX1:  "+startX1+"  startY1 y  : "+startY1+" startX2  :"+startX2+"  startY2 : "+startY2);                if (mstartX1>0&&mstartY1>0){                    path.lineTo(mstartX1,mstartY1);                    canvas.drawPath(path,p1);                    startX=mstartX1;                    startY=mstartY1;                    image.setImageBitmap(baseBitmap);                }                break;            case MotionEvent.ACTION_MOVE:                 mstartX1 = event.getX();                 mstartY1=event.getY();                Log.d(TAG, "按下第二个手指MotionEvent.ACTION_POINTER_DOWN: ");                Log.d(TAG, "按下第二个手指d的坐标: mstartX1:  "+mstartX1+"  mstartY1 y  : "+mstartY1);                canvas.drawPath(path,p1);                canvas.drawLine(startX,startY,mstartX1,mstartY1,p);                image.setImageBitmap(baseBitmap);                break;            case MotionEvent.ACTION_UP:                Log.d(TAG, "MotionEvent.ACTION_UP: ");                path.close();                canvas.drawPath(path,p1);                Log.d(TAG, "最后一个手指抬起来的时候的坐标 mstartX1: "+event.getX()+"-ss--"+mstartX1+"--mstartY1-"+event.getY()+"  ss:"+mstartY1);                image.setImageBitmap(baseBitmap);                break;            case MotionEvent.ACTION_POINTER_UP://                canvas.drawPath(path,p);                Log.d(TAG, "第一根手指抬起来的时候MotionEvent.ACTION_POINTER_UP: ");                break;        }        return true;    }        private void refreshImage(){        if (baseBitmap!=null){            baseBitmap = Bitmap.createBitmap(image.getWidth(), image.getHeight(), Bitmap.Config.ARGB_8888);            bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.a2);            canvas = new Canvas(baseBitmap);            canvas.drawColor(Color.WHITE);            canvas.drawBitmap(bitmap,new Matrix(),p);            path.reset();        }        image.setImageBitmap(baseBitmap);    }        }
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