我正在使用Bitmap创建数字签名图像.在设备上存储签名时,只有签名存储在黑色背景中.我希望绿色背景与签名.

这是我的Bitmap代码

@H_301_4@// Bitmap View public class MyView extends View implements OnClickListener { public int height; public int width; private Bitmap mBitmap; private Path mPath; private Paint mBitmapPaint; public MyView(Context c) { super(c); mPath = new Path(); mBitmapPaint = new Paint(Paint.DITHER_FLAG); } @Override protected void onSizeChanged(int w,int h,int oldw,int oldh) { super.onSizeChanged(w,h,oldw,oldh); Wid = w; Ht = h; mBitmap = Bitmap.createBitmap(w,Bitmap.Config.ARGB_8888); mCanvas = new Canvas(mBitmap); } @Override protected void onDraw(final Canvas canvas) { canvas.drawColor(0xFFFFFFFF); canvas.drawBitmap(mBitmap,mBitmapPaint); canvas.drawPath(mPath,mPaint); // onclick listner for SAVE button saveButton.setOnClickListener(new OnClickListener() { public void onClick(View v) { //capture the image try { saveAsJpg(mBitmap); startActivity(new Intent(Paint.this,SignatureActivity.class)); finish(); } catch (IOException e) { e.printStackTrace(); } } }); } private float mX,mY; private static final float TOUCH_TOLERANCE = 4; private void touch_start(float x,float y) { mPath.reset(); mPath.moveTo(x,y); mX = x; mY = y; System.out.println("---- " +mX); } private void touch_move(float x,float y) { float dx = Math.abs(x - mX); float dy = Math.abs(y - mY); if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) { mPath.quadTo(mX,mY,(x + mX)/2,(y + mY)/2); mX = x; mY = y; } } private void touch_up() { mPath.lineTo(mX,mY); // commit the path to our offscreen mCanvas.drawPath(mPath,mPaint); // kill this so we don't double draw mPath.reset(); } @Override public boolean onTouchEvent(MotionEvent event) { float x = event.getX(); float y = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: touch_start(x,y); invalidate(); break; case MotionEvent.ACTION_MOVE: touch_move(x,y); invalidate(); break; case MotionEvent.ACTION_UP: touch_up(); invalidate(); break; } return true; }

我可以在创建签名时看到绿色背景,但它保存在黑色背景上.请帮帮我,谢谢你