问题描述

我想创建一个从 TextBox 继承的控件，它有一个标签，其中粘贴"到文本框的右侧，并且该文本不是用户可编辑的，而是由属性设置的.如何才能做到这一点?我意识到这个 UX 是一个坏主意的原因可能有很多，但我必须这样做.

I want to make a control which inherits from TextBox and which has a label inside which "sticks" to the right side of the text box and which text is not user-editable but rather is set by a property. How can this be done? I realize there may be many reasons why this UX is a bad idea, but I have to do it this way.

推荐答案

改编自 Hans Passant 的 Winforms 文本框内的按钮答案:

Adapting from Hans Passant's Button inside a winforms textbox answer:

public class TextBoxWithLabel : TextBox {

  [DllImport("user32.dll")]
  private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp);

  Label label = new Label();

  public TextBoxWithLabel() {
    label.BackColor = Color.LightGray;
    label.Cursor = Cursors.Default;
    label.TextAlign = ContentAlignment.MiddleRight;
    this.Controls.Add(label);
  }

  private int LabelWidth() {
    return TextRenderer.MeasureText(label.Text, label.Font).Width;
  }

  public string LabelText {
    get { return label.Text; }
    set {
      label.Text = value;
      SendMessage(this.Handle, 0xd3, (IntPtr)2, (IntPtr)(LabelWidth() << 16));
      OnResize(EventArgs.Empty);
    }
  }

  protected override void OnResize(EventArgs e) {
    base.OnResize(e);
    int labelWidth = LabelWidth();
    label.Left = this.ClientSize.Width - labelWidth;
    label.Top = (this.ClientSize.Height / 2) - (label.Height / 2);
    label.Width = labelWidth;
    label.Height = this.ClientSize.Height;
  }
}

结果:

这篇关于在文本框控件内添加标签的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！