ListBox.HorizontalScrollbar 属性

获取或设置一个值，该值指示是否在控件中显示水平滚动条。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
<LocalizableAttribute(True)> _
Public Property HorizontalScrollbar As Boolean
用法
Dim instance As ListBox
Dim value As Boolean

value = instance.HorizontalScrollbar

instance.HorizontalScrollbar = value

[LocalizableAttribute(true)] 
public bool HorizontalScrollbar { get; set; }

[LocalizableAttribute(true)] 
public:
property bool HorizontalScrollbar {
    bool get ();
    void set (bool value);
}

/** @property */
public boolean get_HorizontalScrollbar ()

/** @property */
public void set_HorizontalScrollbar (boolean value)

public function get HorizontalScrollbar () : boolean

public function set HorizontalScrollbar (value : boolean)

属性值

如果为 true，则在控件中显示水平滚动条；否则为 false。默认为 false。

备注

HorizontalScrollbar 属性确定当 ListBox 内项的宽度超过控件的右边缘时，ListBox 是否应显示水平滚动条。当此属性设置为 true 时，滚动条根据 ListBox 中项的宽度自动显示。如果 ListBox 为所有者描述的 ListBox，为了正确显示水平滚动条，必须设置 HorizontalExtent 属性。

示例

下面的代码示例演示如何使用 HorizontalScrollbar 和 HorizontalExtent 属性来显示用于在 ListBox 控件中显示所有项文本的水平滚动条。该示例还使用 IntegralHeight 属性以确保不会因为 ListBox 控件的大小而不能完整地显示项。此示例要求已将名为 listBox1 的 ListBox 控件添加到窗体中。

Private Sub DisplayHScroll()
   ' Make no partial items are displayed vertically.
   listBox1.IntegralHeight = True
   Dim x As Integer

   ' Add items that are wide to the ListBox.
   For x = 0 To 10
      listBox1.Items.Add("Item  " + x.ToString() + " is a very large value that requires scroll bars")
   Next x

   ' Display a horizontal scroll bar.
   listBox1.HorizontalScrollbar = True

   ' Create a Graphics object to use when determining the size of the largest item in the ListBox.
   Dim g As System.Drawing.Graphics = listBox1.CreateGraphics()


   ' Determine the size for HorizontalExtent using the MeasureString method using the last item in the list.
   Dim hzSize As Integer = g.MeasureString(listBox1.Items(listBox1.Items.Count - 1).ToString(), listBox1.Font).Width
   ' Set the HorizontalExtent property.
   listBox1.HorizontalExtent = hzSize
End Sub

private void DisplayHScroll()
{
   // Make no partial items are displayed vertically.
   listBox1.IntegralHeight = true;

   // Add items that are wide to the ListBox.
   for (int x = 0; x < 10; x++)
   {
      listBox1.Items.Add("Item  " + x.ToString() + " is a very large value that requires scroll bars");
   }

   // Display a horizontal scroll bar.
   listBox1.HorizontalScrollbar = true;

   // Create a Graphics object to use when determining the size of the largest item in the ListBox.
   Graphics g = listBox1.CreateGraphics();

   // Determine the size for HorizontalExtent using the MeasureString method using the last item in the list.
   int hzSize = (int) g.MeasureString(listBox1.Items[listBox1.Items.Count -1].ToString(),listBox1.Font).Width;
   // Set the HorizontalExtent property.
   listBox1.HorizontalExtent = hzSize;
}

private:
   void DisplayHScroll()
   {
      // Make no partial items are displayed vertically.
      listBox1->IntegralHeight = true;

      // Add items that are wide to the ListBox.
      for ( int x = 0; x < 10; x++ )
      {
         listBox1->Items->Add( String::Format( "Item {0} is a very large value that requires scroll bars", x ) );

      }

      // Display a horizontal scroll bar.
      listBox1->HorizontalScrollbar = true;

      // Create a Graphics object to use when determining the size of the largest item in the ListBox.
      Graphics^ g = listBox1->CreateGraphics();

      // Determine the size for HorizontalExtent using the MeasureString method using the last item in the list.
      int hzSize = (int)g->MeasureString( dynamic_cast<String^>(listBox1->Items[ listBox1->Items->Count - 1 ]), listBox1->Font ).Width;

      // Set the HorizontalExtent property.
      listBox1->HorizontalExtent = hzSize;
   }

private void DisplayHScroll()
{
    // Make no partial items are displayed vertically.
    listBox1.set_IntegralHeight(true);

    // Add items that are wide to the ListBox.
    for (int x = 0; x < 10; x++) {
        listBox1.get_Items().Add("Item  " + Convert.ToString(x) 
            + " is a very large value that requires scroll bars");
    }

    // Display a horizontal scroll bar.
    listBox1.set_HorizontalScrollbar(true);

    // Create a Graphics object to use when determining the size 
    // of the largest item in the ListBox.
    Graphics g = listBox1.CreateGraphics();

    // Determine the size for HorizontalExtent using the MeasureString 
    // method using the last item in the list.
    int hzSize = (int)(g.MeasureString(listBox1.get_Items().
        get_Item(listBox1.get_Items().get_Count() - 1).ToString(), 
        listBox1.get_Font()).get_Width());

    // Set the HorizontalExtent property.
    listBox1.set_HorizontalExtent(hzSize);
} //DisplayHScroll

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

ListBox 类
ListBox 成员
System.Windows.Forms 命名空间
ListBox.HorizontalExtent 属性