如何:扩展 ToolStripTextBox,以填充 ToolStrip 的剩余宽度(Windows 窗体)

Stretch控件的ToolStrip属性设置为true时,控件会从头到尾填充其容器,并在其容器调整大小时调整自身大小。 在这种配置中,你可能会发现将控件中的项(例如 ToolStripTextBox)拉伸以填充可用空间,并在控件调整大小时随之调整大小是很有用的。 例如,如果要实现类似于 Microsoft internet® Explorer 中地址栏的外观和行为,此拉伸非常有用。

示例:

下面的代码示例展示一个从 ToolStripTextBox 派生并被命名为 ToolStripSpringTextBox 的类。 此类重写GetPreferredSize方法,用于计算在减去所有其他项的组合宽度后父ToolStrip控件的可用宽度。 此代码示例还提供一个 Form 类和一个 Program 类来演示新行为。

using System;
using System.Drawing;
using System.Windows.Forms;

public class ToolStripSpringTextBox : ToolStripTextBox
{
    public override Size GetPreferredSize(Size constrainingSize)
    {
        // Use the default size if the text box is on the overflow menu
        // or is on a vertical ToolStrip.
        if (IsOnOverflow || Owner.Orientation == Orientation.Vertical)
        {
            return DefaultSize;
        }

        // Declare a variable to store the total available width as
        // it is calculated, starting with the display width of the
        // owning ToolStrip.
        Int32 width = Owner.DisplayRectangle.Width;

        // Subtract the width of the overflow button if it is displayed.
        if (Owner.OverflowButton.Visible)
        {
            width = width - Owner.OverflowButton.Width -
                Owner.OverflowButton.Margin.Horizontal;
        }

        // Declare a variable to maintain a count of ToolStripSpringTextBox
        // items currently displayed in the owning ToolStrip.
        Int32 springBoxCount = 0;

        foreach (ToolStripItem item in Owner.Items)
        {
            // Ignore items on the overflow menu.
            if (item.IsOnOverflow) continue;

            if (item is ToolStripSpringTextBox)
            {
                // For ToolStripSpringTextBox items, increment the count and
                // subtract the margin width from the total available width.
                springBoxCount++;
                width -= item.Margin.Horizontal;
            }
            else
            {
                // For all other items, subtract the full width from the total
                // available width.
                width = width - item.Width - item.Margin.Horizontal;
            }
        }

        // If there are multiple ToolStripSpringTextBox items in the owning
        // ToolStrip, divide the total available width between them.
        if (springBoxCount > 1) width /= springBoxCount;

        // If the available width is less than the default width, use the
        // default width, forcing one or more items onto the overflow menu.
        if (width < DefaultSize.Width) width = DefaultSize.Width;

        // Retrieve the preferred size from the base class, but change the
        // width to the calculated width.
        Size size = base.GetPreferredSize(constrainingSize);
        size.Width = width;
        return size;
    }
}

public class Form1 : Form
{
    public Form1()
    {
        ToolStrip toolStrip1 = new ToolStrip();
        toolStrip1.Dock = DockStyle.Top;
        toolStrip1.Items.Add(new ToolStripLabel("Address"));
        toolStrip1.Items.Add(new ToolStripSpringTextBox());
        toolStrip1.Items.Add(new ToolStripButton("Go"));
        Controls.Add(toolStrip1);
        Text = "ToolStripSpringTextBox demo";
    }
}

static class Program
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}
Imports System.Drawing
Imports System.Windows.Forms

Public Class ToolStripSpringTextBox
    Inherits ToolStripTextBox

    Public Overrides Function GetPreferredSize( _
        ByVal constrainingSize As Size) As Size

        ' Use the default size if the text box is on the overflow menu
        ' or is on a vertical ToolStrip.
        If IsOnOverflow Or Owner.Orientation = Orientation.Vertical Then
            Return DefaultSize
        End If

        ' Declare a variable to store the total available width as 
        ' it is calculated, starting with the display width of the 
        ' owning ToolStrip.
        Dim width As Int32 = Owner.DisplayRectangle.Width

        ' Subtract the width of the overflow button if it is displayed. 
        If Owner.OverflowButton.Visible Then
            width = width - Owner.OverflowButton.Width - _
                Owner.OverflowButton.Margin.Horizontal()
        End If

        ' Declare a variable to maintain a count of ToolStripSpringTextBox 
        ' items currently displayed in the owning ToolStrip. 
        Dim springBoxCount As Int32 = 0

        For Each item As ToolStripItem In Owner.Items

            ' Ignore items on the overflow menu.
            If item.IsOnOverflow Then Continue For

            If TypeOf item Is ToolStripSpringTextBox Then
                ' For ToolStripSpringTextBox items, increment the count and 
                ' subtract the margin width from the total available width.
                springBoxCount += 1
                width -= item.Margin.Horizontal
            Else
                ' For all other items, subtract the full width from the total
                ' available width.
                width = width - item.Width - item.Margin.Horizontal
            End If
        Next

        ' If there are multiple ToolStripSpringTextBox items in the owning
        ' ToolStrip, divide the total available width between them. 
        If springBoxCount > 1 Then width = CInt(width / springBoxCount)

        ' If the available width is less than the default width, use the
        ' default width, forcing one or more items onto the overflow menu.
        If width < DefaultSize.Width Then width = DefaultSize.Width

        ' Retrieve the preferred size from the base class, but change the
        ' width to the calculated width. 
        Dim preferredSize As Size = MyBase.GetPreferredSize(constrainingSize)
        preferredSize.Width = width
        Return preferredSize

    End Function
End Class

Public Class Form1
    Inherits Form

    Public Sub New()
        Dim toolStrip1 As New ToolStrip()
        With toolStrip1
            .Dock = DockStyle.Top
            .Items.Add(New ToolStripLabel("Address"))
            .Items.Add(New ToolStripSpringTextBox())
            .Items.Add(New ToolStripButton("Go"))
        End With
        Controls.Add(toolStrip1)
        Text = "ToolStripSpringTextBox demo"
    End Sub

End Class

Public Class Program

    <STAThread()> Public Shared Sub Main()
        Application.EnableVisualStyles()
        Application.SetCompatibleTextRenderingDefault(False)
        Application.Run(New Form1())
    End Sub

End Class

编译代码

此示例需要:

  • 对 System、System.Drawing 和 System.Windows.Forms 程序集的引用。

另请参阅