Question

我使用矩阵类来缩放我的图像。但我不知道如何裁剪缩放的图像。

我想我应该在ZOOM模式下修复偏移。

请帮帮我

public class PP2cropActivity extends Activity implements OnTouchListener {

        private static final String TAG = "Touch";


        Button cropbtn;
        float offx, offy; 
        float addX2, addY2; 
        float sx, sy, ex, ey;
        float scale;

        Matrix matrix = new Matrix();
        Matrix savedMatrix = new Matrix();
        static final int NONE = 0;
        static final int DRAG = 1;
        static final int ZOOM = 2;
        int mode = NONE;

        PointF start = new PointF();
        PointF mid = new PointF();
        PointF end = new PointF();

        float oldDist = 1f;
        Bitmap bPhoto;
        String mImgpath;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            Intent intent = getIntent(); 
            mImgpath = intent.getStringExtra("mImgpath");

             bPhoto = BitmapFactory.decodeFile(mImgpath);
             bPhoto = Bitmap.createScaledBitmap(bPhoto, 400, 600, true);

             cropbtn = (Button)findViewById(R.id.confirmbtn);

             cropbtn.setOnClickListener(new OnClickListener(){
                public void onClick(View arg0) {

                    PP2mainActivity.mCropedImage = Bitmap.createBitmap(bPhoto, (int)addX2, (int)addY2, 100, 100);
                    Intent intent = new Intent(PP2cropActivity.this, PP2mainActivity.class);
                    startActivity(intent); 

                }
            });

            ImageView view = (ImageView) findViewById(R.id.matrixview);
            view.setImageBitmap(bPhoto);
            view.setOnTouchListener(this);
        }


        public boolean onTouch(View v, MotionEvent event) {
            ImageView view = (ImageView) v;

            // Dump touch event to log


            // Handle touch events here...
                switch (event.getAction() & MotionEvent.ACTION_MASK) {
                case MotionEvent.ACTION_DOWN:
                    savedMatrix.set(matrix);
                    start.set(event.getX(), event.getY());
                    Log.d(TAG, "mode=DRAG");
                    sx = event.getX();
                    sy = event.getY();

                    mode = DRAG;
                    break;

                case MotionEvent.ACTION_POINTER_DOWN:
                    oldDist = spacing(event);
                    Log.d(TAG, "oldDist=" + oldDist);
                    if (oldDist > 10f) {
                        savedMatrix.set(matrix);
                        midPoint(mid, event);
                        mode = ZOOM;
                            Log.d(TAG, "mode=ZOOM");
                    }
                    break;
                case MotionEvent.ACTION_UP:
                    if(mode ==DRAG) { 
                    addX2 = -offx +10;
                    addY2 = -offy +10; 
                    mode = NONE;
                    Log.d("point", "addX2 : " + addX2 + "addY2 : " + addY2);
                    } else if(mode ==ZOOM)
                    {
                        addX2 = (-offx+10)*scale;
                        addY2 = (-offy+10)*scale;
                    }
                    break; 
                case MotionEvent.ACTION_POINTER_UP:
                        mode = NONE;
                        Log.d(TAG, "mode=NONE");
                        break;
                case MotionEvent.ACTION_MOVE:
                    if (mode == DRAG) {
                        // ...
                        matrix.set(savedMatrix);
                        ex = event.getX();
                        ey = event.getY();

                         offx +=(int)(ex-sx);
                         offy +=(int)(ey-sy);
                         sx = ex;
                         sy = ey;

                        Log.d("off", "offx : " + offx+ " , offy : " + offy);
                        matrix.postTranslate(event.getX()- start.x, event.getY()- start.y);


                    }
                    else if (mode == ZOOM) {

                            float newDist = spacing(event);
                            Log.d(TAG, "newDist=" + newDist);
                            if (newDist > 10f) {
                                    matrix.set(savedMatrix);
                                 scale = newDist / oldDist;
                                    matrix.postScale(scale, scale, mid.x, mid.y);   
                            }
                            offx +=  (int)(ex-sx) /scale;
                            offy +=  (int)(ey-sy) /scale;
                            sx = ex;
                            sy = ey;
                    }
                    break;
                }

                view.setImageMatrix(matrix);
                return true; // indicate event was handled
        }


        /** Determine the space between the first two fingers */
        private float spacing(MotionEvent event) {
            float x = event.getX(0) - event.getX(1);
            float y = event.getY(0) - event.getY(1);
            return FloatMath.sqrt(x * x + y * y);
        }

        /** Calculate the mid point of the first two fingers */
        private void midPoint(PointF point, MotionEvent event) {
            float x = event.getX(0) + event.getX(1);
            float y = event.getY(0) + event.getY(1);
            point.set(x / 2, y / 2);
        }
}

Answer 1

裁剪图片：

Bitmap originalBitmap = BitmapFactory.decodeResource(getResources(), 
                R.drawable.test_image);
Bitmap croppedBitmap = Bitmap.createBitmap(originalBitmap, x, y, width, height);

我该如何裁剪图像？

1 个答案: