根据内容调整 RichTextBox 的大小

Question

此代码根据内容自动调整 RichTextBox 的大小。我遇到了问题，尤其是桌子。 \t 可能会被忽略。我尝试了托管解决方案，现在我正在尝试平台调用。当前输出：

    [DllImport("gdi32.dll")]
    static extern bool GetTextExtentPoint32(IntPtr hdc, string lpString, int cbString, out SIZE lpSize);

    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr GetDC(IntPtr hWnd);

    [StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
    public struct SIZE
    {
        public int cx;
        public int cy;

        public SIZE(int cx, int cy)
        {
            this.cx = cx;
            this.cy = cy;
        }
    }

    public static void Main()
    {
        Form form = new Form();
        RichTextBox rtfBox = new RichTextBox();

        rtfBox.Rtf = @"{\rtf1\ansi\deff0{\fonttbl{\f0\fnil Arial;}}\viewkind4\uc1\trowd\trgaph100\cellx1000\cellx2000\pard\intbl\lang1033\f0\fs20  hi\cell  bye\cell\row\intbl  one\cell  two\cell\row\pard\par}";
        rtfBox.ScrollBars = RichTextBoxScrollBars.None;

        string sInput = "hi\t bye\t\n";// one\t two\t\n";
        SIZE CharSize;

        form.Controls.Add(rtfBox);

        IntPtr hdc = GetDC(IntPtr.Zero);//Context for entire screen
        GetTextExtentPoint32(hdc, sInput, sInput.Length, out CharSize);

        rtfBox.Width = CharSize.cx;
        rtfBox.Height = CharSize.cy;

        form.Visible = false;

        form.ShowDialog();
    }

（注意，为简单起见，这是一个引用 System.Windows.Forms.dll 的控制台应用程序）

Answer 1

您看过ContentsResized 事件吗？添加以下事件触发时调用的方法：

private void richTextBox_ContentsResized(object sender, ContentsResizedEventArgs e)
{
    var richTextBox = (RichTextBox) sender;
    richTextBox.Width = e.NewRectangle.Width;
    richTextBox.Height = e.NewRectangle.Height;
}

当 RTF 内容发生变化时（使用Rtf），RichTextBox 应该调整大小以匹配其内容。确保您还将WordWrap 属性设置为false。

---

我已经用你的表格示例进行了尝试，它似乎确实可以工作（尽管有一点偏移，你可以通过在调整后的大小上添加几个像素的宽度来解决这个问题 - 不知道为什么会发生这种情况）：

P.Brian.Mackey 编辑
这个答案对我有用。澄清一下，这是包含边框修复的最终代码：

    public static void Main()
    {
        string sInput = "hi\t bye\t\n";// one\t two\t\n";
        SIZE CharSize;
        Form form = new Form();
        RichTextBox rtfBox = new RichTextBox();
        rtfBox.ContentsResized += (object sender, ContentsResizedEventArgs e) =>
        {
            var richTextBox = (RichTextBox)sender;
            richTextBox.Width = e.NewRectangle.Width;
            richTextBox.Height = e.NewRectangle.Height;
            rtfBox.Width += rtfBox.Margin.Horizontal + SystemInformation.HorizontalResizeBorderThickness;
        };

        rtfBox.WordWrap = false;
        rtfBox.ScrollBars = RichTextBoxScrollBars.None;

        rtfBox.Rtf = @"{\rtf1\ansi\deff0{\fonttbl{\f0\fnil Arial;}}\viewkind4\uc1\trowd\trgaph100\cellx1000\cellx2000\pard\intbl\lang1033\f0\fs20  hi\cell  bye\cell\row\intbl  one\cell  two\cell\row\pard\par}";

        form.Controls.Add(rtfBox);
        form.ShowDialog();
    }

Answer 2

如this answer中所述，使用GetPreferredSize 要容易得多。那么你就不需要等待 ContentsResized 事件了，

Answer 3

身高呢？
我加了

richTextBox.Height += richTextBox.Margin.Vertical +  
SystemInformation.VerticalResizeBorderThickness;  

最后。

它看起来也很适合扩展方法：

static public class RichTextBoxResizer {  
    static public void ResizeToContents(this RichTextBox richTextBox, ContentsResizedEventArgs e) {  
        richTextBox.Width = e.NewRectangle.Width;  
        richTextBox.Height = e.NewRectangle.Height;  

        richTextBox.Width += richTextBox.Margin.Horizontal +  
            SystemInformation.HorizontalResizeBorderThickness +  
            SystemInformation.HorizontalScrollBarThumbWidth;  

        richTextBox.Height += richTextBox.Margin.Vertical +  
            SystemInformation.VerticalResizeBorderThickness;  
    }   

    static public void ResizeToContentsHorizontally(this RichTextBox richTextBox, ContentsResizedEventArgs e) {
        richTextBox.Width = e.NewRectangle.Width;

        richTextBox.Width += richTextBox.Margin.Horizontal +
            SystemInformation.HorizontalResizeBorderThickness +
            SystemInformation.HorizontalScrollBarThumbWidth;
    }

    static public void ResizeToContentsVertically(this RichTextBox richTextBox, ContentsResizedEventArgs e) {
        richTextBox.Height = e.NewRectangle.Height;

        richTextBox.Height += richTextBox.Margin.Vertical +
            SystemInformation.VerticalResizeBorderThickness;
    }
}

所以事件接收器看起来像：

private void rtfBox_ContentsResized(object sender, ContentsResizedEventArgs e) {  
    RichTextBox rtb = (RichTextBox)sender;  
    rtb.ResizeToContents(e);  
}