在画布上绘制时，路径弧比线弧更粗

Question

我正在创建一个自定义视图，使用画布绘制一个带圆角的简单线条，我无法让角落中的线条与直线部分具有相同的厚度。路径在onSizeChanged方法中定义。

这就是我的观点：

这是观点

public class CanvasView extends View {

private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
Context context;

public CanvasView(Context c) {
    super(c);
    context = c;
    mPath = new Path();
    mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}

public CanvasView(Context c, AttributeSet attrs) {
    super(c, attrs);
    context = 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);
    if(mBitmap == null) {

        RectF rectf = new RectF(w - w / 2, h - w / 2, w, h);
        mPath.moveTo(w, 0);
        mPath.lineTo(w, h - w / 2);
        mPath.arcTo(rectf, 0, 90);
        mPath.lineTo(0, h);

        mBitmapPaint.setAntiAlias(true);
        mBitmapPaint.setDither(true);
        mBitmapPaint.setColor(context.getResources().getColor(R.color.siminn_warm_gray));
        mBitmapPaint.setStyle(Paint.Style.STROKE);

        mBitmapPaint.setStrokeWidth(5);
    }
}


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

    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
    canvas.drawPath(mPath, mBitmapPaint);

}
}

Answer 1

当您使用画布绘图时，您必须使用帐户视图填充。 onSizeChanged方法为您提供了没有填充的witdh和视图的高度。要获得填充，您可以在View类中使用getPaddingTop()，getPaddingBottom()，getPaddingStart()和getPaddingEnd()函数。这将是考虑填充的代码：

@Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        int realWidth = w - (getPaddingStart() + getPaddingEnd());
        int realHeight = h - (getPaddingTop() + getPaddingBottom());

        if (mBitmap == null) {
            RectF rectf = new RectF(realWidth - realWidth / 2, realHeight - realWidth / 2, realWidth, realHeight);
            mPath.moveTo(realWidth, getPaddingTop());
            mPath.lineTo(realWidth, realHeight - realWidth / 2);
            mPath.arcTo(rectf, 0, 90);
            mPath.lineTo(getPaddingStart(), realHeight);

            mBitmapPaint.setAntiAlias(true);
            mBitmapPaint.setDither(true);
            mBitmapPaint.setColor(context.getResources().getColor(R.color.siminn_warm_gray));
            mBitmapPaint.setStyle(Paint.Style.STROKE);
            mBitmapPaint.setStrokeWidth(5);
        }
    }

Answer 2

我想通了，我沿着画布的边缘画画，其效果只显示了一半的线条。我从边缘移动了一点线，它正在工作