Question

我想创建可以导入位图并在位图上绘制的活动。现在我可以导入但我不能在位图上绘画。

    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        mCanvas = new Canvas(mBitmap);
        //mCanvas.drawColor(0xffffffff);
    }

    protected void onDraw(Canvas canvas) {
        //canvas.drawColor(0xffffffff);

        canvas.drawBitmap(bitmap, 0, 0, mBitmapPaint);

        canvas.drawPath(mPath, mPaint);
    }

谢谢。

Answer 1

从您的评论“绘制路径显示一段时间”，我猜测用户的绘画显示但很快就会消失。这是因为您不断在用户绘图上重绘位图。添加一个布尔检查以确保只绘制一次位图：

Boolean first = true;

protected void onDraw(Canvas canvas){
    if(first) canvas.drawBitmap(bitmap, 0, 0, mBitmapPaint);
    first = false;
    canvas.drawPath(mPath, mPaint);
}

可以将bitmap导入fingerPaint Activity吗？

1 个答案: