Question

我正在尝试制作http://arapaho.nsuok.edu/~deckar01/Zvis.html

的原生Android版本

所以，我制作了一个自定义视图，可以绘制所需的所有方块。当然，一旦数字变得足够大以使Canvas开始绘制数千个正方形，这个绘图最终会花费10秒钟。

有更好的方法吗？似乎有一些显而易见的东西，我不打算做/使用。

View的onDraw方法如下，如果有帮助的话。有什么想法吗？

 protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    final int number = mNumber;
    final float tileWidth, tileHeight;

    /*mTileWidth = mWW / (number - 1);
    mTileHeight = mHH / (number - 1);*/

    // make them squares
    if (mWW <= mHH) {
        tileWidth = tileHeight = mWW / (number - 1);
    } else {
        tileWidth = tileHeight = mHH / (number - 1);
    }

    mWhiteTextPaint.setTextSize(48f / 72 * tileWidth);
    mBlackTextPaint.setTextSize(48f / 72 * tileWidth);

    float currX = getPaddingLeft();
    float currY = getPaddingTop();

    for (int i = 1; i <= number - 1; i++) {
        mBackgroundPaint.setColor(getBackgroundColor(i, number));
        canvas.drawRect(currX, currY, currX + tileWidth,
                currY + tileHeight,
                mBackgroundPaint);
        final String text = String.valueOf(i);
        canvas.drawText(text,
                currX + tileWidth / 2 - mWhiteTextPaint.measureText(text) / 2,
                currY + tileHeight * 0.9f, mWhiteTextPaint);
        currX += tileWidth;
    }
    currX = getPaddingLeft();
    currY += tileHeight;

    for (int i = 2; i <= number - 1; i++) {
        for (int j = 1; j <= number - 1; j++) {
            final int num = (j == 1) ? i : (i * j) % number;

            mBackgroundPaint.setColor(getBackgroundColor(num, number));
            canvas.drawRect(currX, currY, currX + tileWidth,
                    currY + tileHeight,
                    mBackgroundPaint);
            final String text = String.valueOf(num);
            if (num == 0) {
                canvas.drawText(text,
                        currX + tileWidth / 2 - mBlackTextPaint.measureText(text) / 2,
                        currY + tileHeight * 0.9f, mBlackTextPaint);
            } else {
                canvas.drawText(text,
                        currX + tileWidth / 2 - mWhiteTextPaint.measureText(text) / 2,
                        currY + tileHeight * 0.9f, mWhiteTextPaint);
            }
            currX += tileWidth;
        }
        currX = getPaddingLeft();
        currY += tileHeight;
    }

    if (mOnDrawFinishedListener != null) {
        mOnDrawFinishedListener.onDrawFinished(number);
    }
}

Answer 1

正如@CarCzar已经说过的那样，你可以将一个单独的线程中的所有内容绘制成一个位图，然后在UI线程中，你只能在屏幕上绘制该位图。或者，您可以使用OpenGL。这通常用于游戏等更具活力的东西。问题是OpenGL在一个单独的图形线程中运行，因此不会阻止你的UI。

使用Canvas绘制数千个Rect

1 个答案: