不同 API 上的 Android 绘画问题

Question

我在为 Android 的不同 API 使用画图时遇到问题。

用户应该能够在一个区域上绘制字母，这在 API 8 和 10 上运行良好，但对于 API 16 和 17，线条看起来非常不同。我将使用图片展示。

这就是它应该看起来的样子，API 8 .

这是它在 API 16 上的样子.

这是我的绘制 View 代码:

public class TouchDrawView extends View
{
    private Paint mPaint;
    private ArrayList<Point> mPoints;
    private ArrayList<ArrayList<Point>> mStrokes;

    public TouchDrawView(Context context)
    {
        super(context);

        mPoints = new ArrayList<Point>();
        mStrokes = new ArrayList<ArrayList<Point>>();
        mPaint = createPaint(Color.BLACK, 14);
    }

    @Override
    public void onDraw(Canvas c)
    {
        super.onDraw(c);

        for(ArrayList<Point> points: mStrokes)
        {
            drawStroke(points, c);
        }

        drawStroke(mPoints, c);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event)
    {
        if(event.getActionMasked() == MotionEvent.ACTION_MOVE)
        {
            mPoints.add(new Point((int) event.getX(), (int) event.getY()));

            this.invalidate();
        }

        if(event.getActionMasked() == MotionEvent.ACTION_UP)
        {
            mStrokes.add(mPoints);
            mPoints = new ArrayList();
        }

        return true;
    }

    private void drawStroke(ArrayList stroke, Canvas c)
    {
        if (stroke.size() > 0)
        {
            Point p0 = (Point)stroke.get(0);

            for (int i = 1; i < stroke.size(); i++)
            {
                Point p1 = (Point)stroke.get(i);
                c.drawLine(p0.x, p0.y, p1.x, p1.y, mPaint);
                p0 = p1;
            }
        }
    }

    public void clear()
    {
        mPoints.clear();
        mStrokes.clear();

        this.invalidate();
    }

    private Paint createPaint(int color, float width)
    {
        Paint temp = new Paint();
        temp.setStyle(Paint.Style.FILL_AND_STROKE);
        temp.setAntiAlias(true);
        temp.setColor(color);
        temp.setStrokeWidth(width);
        temp.setStrokeCap(Paint.Cap.ROUND);

        return temp;
    }
}

Answer 1

看来您的应用程序是硬件加速的，在此模式下不支持 setStrokeCap()(对于线条)等功能，请查看:http://developer.android.com/guide/topics/graphics/hardware-accel.html#unsupported

只需禁用硬件加速并重试。这是您禁用它的方式:

<application android:hardwareAccelerated="false" ...>