如何：拉伸 ToolStripTextBox 以填充 ToolStrip 的其余宽度（Windows 窗体）

http://msdn.microsoft.com/zh-cn/library/ms404304.aspx

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

publicclass ToolStripSpringTextBox : ToolStripTextBox
{
publicoverride 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;
}
}

publicclass 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";
}
}

staticclass Program
{
[STAThread]
staticvoid Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}