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VB.NET ComboBox.DropDownWidth属性代码示例

本文整理汇总了VB.NET中System.Windows.Forms.ComboBox.DropDownWidth属性的典型用法代码示例。如果您正苦于以下问题:VB.NET ComboBox.DropDownWidth属性的具体用法?VB.NET ComboBox.DropDownWidth怎么用?VB.NET ComboBox.DropDownWidth使用的例子?那么恭喜您, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在System.Windows.Forms.ComboBox的用法示例。


在下文中一共展示了ComboBox.DropDownWidth属性的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的VB.NET代码示例。

示例1: InitializeComboBox

Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox
  Private animals() As String

  ' This method initializes the owner-drawn combo box.
  ' The drop-down width is set much wider than the size of the combo box
  ' to accomodate the large items in the list.  The drop-down style is set to 
  ' ComboBox.DropDown, which requires the user to click on the arrow to 
  ' see the list.
  Private Sub InitializeComboBox()
      Me.ComboBox1 = New ComboBox
      Me.ComboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawVariable
      Me.ComboBox1.Location = New System.Drawing.Point(10, 20)
      Me.ComboBox1.Name = "ComboBox1"
      Me.ComboBox1.Size = New System.Drawing.Size(100, 120)
      Me.ComboBox1.DropDownWidth = 250
      Me.ComboBox1.TabIndex = 0
      Me.ComboBox1.DropDownStyle = ComboBoxStyle.DropDown
      animals = New String() {"Elephant", "c r o c o d i l e", "lion"}
      ComboBox1.DataSource = animals
      Me.Controls.Add(Me.ComboBox1)
  End Sub

  ' If you set the Draw property to DrawMode.OwnerDrawVariable, 
  ' you must handle the MeasureItem event. This event handler 
  ' will set the height and width of each item before it is drawn. 
   Private Sub ComboBox1_MeasureItem(ByVal sender As Object, _
      ByVal e As System.Windows.Forms.MeasureItemEventArgs) _
          Handles ComboBox1.MeasureItem

      Select Case e.Index
          Case 0
              e.ItemHeight = 45
          Case 1
              e.ItemHeight = 20
          Case 2
              e.ItemHeight = 35
      End Select
      e.ItemWidth = 260

  End Sub

  ' You must handle the DrawItem event for owner-drawn combo boxes.  
  ' This event handler changes the color, size and font of an 
  ' item based on its position in the array.
  Private Sub ComboBox1_DrawItem(ByVal sender As Object,  _ 
      ByVal e As System.Windows.Forms.DrawItemEventArgs) _
      Handles ComboBox1.DrawItem

      Dim size As Single
      Dim myFont As System.Drawing.Font
      Dim family As FontFamily

      Dim animalColor As New System.Drawing.Color
      Select Case e.Index
          Case 0
              size = 30
              animalColor = System.Drawing.Color.Gray
              family = FontFamily.GenericSansSerif
          Case 1
              size = 10
              animalColor = System.Drawing.Color.LawnGreen
              family = FontFamily.GenericMonospace
          Case 2
              size = 15
              animalColor = System.Drawing.Color.Tan
              family = FontFamily.GenericSansSerif
      End Select

      ' Draw the background of the item.
      e.DrawBackground()

      ' Create a square filled with the animals color. Vary the size
      ' of the rectangle based on the length of the animals name.
      Dim rectangle As Rectangle = New Rectangle(2, e.Bounds.Top + 2, _
          e.Bounds.Height, e.Bounds.Height - 4)
      e.Graphics.FillRectangle(New SolidBrush(animalColor), rectangle)

      ' Draw each string in the array, using a different size, color,
      ' and font for each item.
      myFont = New Font(family, size, FontStyle.Bold)
      e.Graphics.DrawString(animals(e.Index), myFont, System.Drawing.Brushes.Black, _
          New RectangleF(e.Bounds.X + rectangle.Width, e.Bounds.Y, _ 
          e.Bounds.Width, e.Bounds.Height))

      ' Draw the focus rectangle if the mouse hovers over an item.
      e.DrawFocusRectangle()
  End Sub
开发者ID:VB.NET开发者,项目名称:System.Windows.Forms,代码行数:87,代码来源:ComboBox.DropDownWidth


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