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
// 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
解决方法
@rahul你也可以在onDraw中使用它
canvas.drawColor(Color.GREEN);
请检查我的代码的更新
@Override
protected void onSizeChanged(int w,int oldh) {
mBitmap = Bitmap.createBitmap(w,Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mCanvas.drawColor(Color.GREEN);
super.onSizeChanged(w,oldh);
}