在画布上绘图并在绘图后调整画布的大小

Question

我正在基于Soundbitrate绘制Canvas内部声音的WaveForm，但是画布覆盖了设备的全屏宽度，但是我想根据画布的内部内容绘制画布宽度。 有谁知道抽奖后如何缩放画布的大小？ 这是画布内部的draw（）方法。

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

        canvasWidth = canvas.getWidth();

        if (mSoundFile == null)
            return;

        if (mHeightsAtThisZoomLevel == null)
            computeIntsForThisZoomLevel();

        // Draw waveform
        int measuredWidth = getMeasuredWidth();
        int measuredHeight = getMeasuredHeight();
        int start = mOffset;
        int width = mHeightsAtThisZoomLevel.length - start;
        int ctr = measuredHeight / 2;

        if (width > measuredWidth)
            width = measuredWidth;

        // Draw grid
        double onePixelInSecs = pixelsToSeconds(1);
        boolean onlyEveryFiveSecs = (onePixelInSecs > 1.0 / 50.0);
        double fractionalSecs = mOffset * onePixelInSecs;
        int integerSecs = (int) fractionalSecs;
        int i = 0;
        while (i <width) {
            i++;
            fractionalSecs += onePixelInSecs;
            int integerSecsNew = (int) fractionalSecs;
            if (integerSecsNew != integerSecs) {
                integerSecs = integerSecsNew;
                if (!onlyEveryFiveSecs || 0 == (integerSecs % 5)) {
                    canvas.drawLine(i, 0, i, measuredHeight, mGridPaint);
                }
            }
        }

        i=0;
        while (i < width-1) {
            i++;
            Paint paint;
            if (i + start >= mSelectionStart &&
                    i + start < mSelectionEnd) {
                paint = mSelectedLinePaint;
            } else {
                drawWaveformLine(canvas, i, 0, measuredHeight,
                        mUnselectedBkgndLinePaint);
                paint = mUnselectedLinePaint;
            }
            drawWaveformLine(
                    canvas, i,
                    ctr - mHeightsAtThisZoomLevel[start + i],
                    ctr + 1 + mHeightsAtThisZoomLevel[start + i],
                    paint);

            if (i + start == mPlaybackPos) {
                canvas.drawLine(i /*+ (canvas.getWidth() / 2)*/, 0, i/* + (canvas.getWidth() / 2)*/, measuredHeight, mPlaybackLinePaint);
            }
        }

}```