GraphicsPath消除文本边框

Question

我使用GraphicsPath对象在矩形中绘制文本。矩形比文本大，我想在矩形的任何角落，也在它的边缘中心绘制文本。

我遇到的问题是，当我绘制路径时，源矩形周围会留下一个边框。我希望能够消除该边框，并使文本触摸它的边界矩形。

下面是我的代码：

private void Form1_Paint(object sender, PaintEventArgs e)
{
    var g = e.Graphics;
    g.SmoothingMode = SmoothingMode.HighQuality;

    Rectangle textRect = new Rectangle(100, 100, 150, 150);
    Font f = new Font("Arial", 16);
    float emSize = f.Height * f.FontFamily.GetCellAscent(f.Style) /
               f.FontFamily.GetEmHeight(f.Style);

    foreach (StringAlignment lineAlignment in Enum.GetValues(typeof(StringAlignment)))
    {
        foreach (StringAlignment alignment in Enum.GetValues(typeof(StringAlignment)))
        {
            StringFormat sf = new StringFormat() { LineAlignment = lineAlignment, Alignment = alignment };
            using (GraphicsPath gp = new GraphicsPath())
            {
                gp.AddString("txt", f.FontFamily, (int)f.Style, emSize, textRect, sf);
                RectangleF bounds = gp.GetBounds();
                g.FillPath(Brushes.Black, gp);
                g.DrawRectangle(Pens.Red, Rectangle.Round(bounds));
            }
        }
    }          

    g.DrawRectangle(Pens.Blue, textRect);
}

其结果是：

​

​

基本上，我希望红色矩形(和它们包含的文本)触摸蓝色矩形，并消除它们之间的边框。另外，我需要使用GraphicsPath而不是DrawString。

Answer 1

最后，我编写了一个帮助方法来计算矩形的偏移量，并在绘制它之前翻译文本。下面是我写的方法：

private PointF FixAlignment(RectangleF parentRect, RectangleF childRect,
    StringAlignment lineAlignment, StringAlignment alignment)
{
    float xOffset = 0;
    float yOffset = 0;

    switch (lineAlignment)
    {
        case StringAlignment.Near:
            yOffset = parentRect.Top - childRect.Top;
            break;
        case StringAlignment.Far:
            yOffset = parentRect.Bottom - childRect.Bottom;
            break;
    }

    switch (alignment)
    {
        case StringAlignment.Near:
            xOffset = parentRect.Left - childRect.Left;
            break;
        case StringAlignment.Far:
            xOffset = parentRect.Right - childRect.Right;
            break;
    }

    return new PointF(xOffset, yOffset);
}

我在Form1_Paint方法中使用它，如下所示：

private void Form1_Paint(object sender, PaintEventArgs e)
{
    var g = e.Graphics;
    g.SmoothingMode = SmoothingMode.HighQuality;

    Rectangle textRect = new Rectangle(100, 100, 150, 150);
    Font f = new Font("Arial", 16);
    float emSize = f.Height * f.FontFamily.GetCellAscent(f.Style) /
               f.FontFamily.GetEmHeight(f.Style);

    foreach (StringAlignment lineAlignment in Enum.GetValues(typeof(StringAlignment)))
    {
        foreach (StringAlignment alignment in Enum.GetValues(typeof(StringAlignment)))
        {
            StringFormat sf = new StringFormat() { LineAlignment = lineAlignment, Alignment = alignment };
            using (GraphicsPath gp = new GraphicsPath())
            {
                gp.AddString("txt", f.FontFamily, (int)f.Style, emSize, textRect, sf);
                RectangleF bounds = gp.GetBounds();

                // Calculate the rectangle offset
                PointF offset = FixAlignment(textRect, bounds, lineAlignment, alignment);
                // Translate using the offset
                g.TranslateTransform(offset.X, offset.Y);
                g.FillPath(Brushes.Black, gp);
                g.DrawRectangle(Pens.Red, Rectangle.Round(bounds));

                // Translate back to the original location
                g.TranslateTransform(-offset.X, -offset.Y);
            }
        }
    }

    g.DrawRectangle(Pens.Blue, textRect);
}

结果如下：

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​