.net - 自定义 Winforms 控件中的基线对齐线

Question

我有一个带有文本框的自定义用户控件，我想在自定义控件之外公开(文本框中文本的)对齐线的基线。我知道您创建了一个设计器(继承自 ControlDesigner)并重写 SnapLines 以访问对齐线，但我想知道如何获取我通过自定义用户控件公开的控件的文本基线。

Answer 1

作为 Miral 答案的更新.. 对于正在寻找如何执行此操作的新人，这里有一些“缺失的步骤”。 :) 除了更改一些值以引用将要修改的 UserControl 之外，上面的 C# 代码几乎已“插入”就绪。

可能需要的引用资料:
系统设计 (@robyaw)

所需用途:

using System.Windows.Forms.Design;
using System.Windows.Forms.Design.Behavior;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Collections;

在您的用户控件上，您需要以下属性:

[Designer(typeof(MyCustomDesigner))]

然后您需要一个“设计器”类来覆盖 SnapLines:

private class MyCustomerDesigner : ControlDesigner {
  public override IList SnapLines {
    get {
     /* Code from above */
    IList snapLines = base.SnapLines;

    // *** This will need to be modified to match your user control
    MyControl control = Control as MyControl;
    if (control == null) { return snapLines; }

    // *** This will need to be modified to match the item in your user control
    // This is the control in your UC that you want SnapLines for the entire UC
    IDesigner designer = TypeDescriptor.CreateDesigner(
        control.textBoxValue, typeof(IDesigner));
    if (designer == null) { return snapLines; }

    // *** This will need to be modified to match the item in your user control
    designer.Initialize(control.textBoxValue);

    using (designer)
    {
        ControlDesigner boxDesigner = designer as ControlDesigner;
        if (boxDesigner == null) { return snapLines; }

        foreach (SnapLine line in boxDesigner.SnapLines)
        {
            if (line.SnapLineType == SnapLineType.Baseline)
            {
                // *** This will need to be modified to match the item in your user control
                snapLines.Add(new SnapLine(SnapLineType.Baseline,
                    line.Offset + control.textBoxValue.Top,
                    line.Filter, line.Priority));
                break;
            }
        }
    }

    return snapLines;
}

    }
  }
}