我已经搜索过显示datagridview的tooltiptext但是我只获得了datagridviewcell的tooltiptext。我想要的是从datagridviewcomboboxcolumn的下拉列表中突出显示项目（鼠标悬停）时显示的工具提示。 我在comboboxcolumn的数据绑定中设置了tooltiptext，但它在运行时没有显示任何内容。
'assuming dtExpense is the datatable used as datasource
With CType(DataGridView3.Columns(2), DataGridViewComboBoxColumn)
.AutoComplete = True
.DataSource = dtExpense
.DisplayMember = "acct_title"
.ValueMember = "acct_id"
.DataPropertyName = "acct_id"
.ToolTipText = "description"
End With
任何人都可以告诉我如何做到这一点。在datagriviewcell.tooltiptext中，它必须在某个时刻绘制。我正在考虑如何使用datagridviewcomboboxcolumn执行此操作，并且必须显示组合框中的每个项目。
答案 0 :(得分：0)
假设您有一个名为string的{{1}}属性的对象类（显示为下拉项）和acct_title（要显示为这些下拉项目的工具提示），您就是＆＃39 ;我想：
处理DataGridView的description事件，以将事件处理程序添加到基础ComboBox。
EditingControlShowing处理ComboBox Me.DataGridView3.EditingControlShowing += DataGridView3_EditingControlShowing
Private Sub DataGridView3_EditingControlShowing(sender As Object, e As DataGridViewEditingControlShowingEventArgs)
If TypeOf e.Control Is ComboBox Then
Dim cb As ComboBox = TryCast(e.Control, ComboBox)
cb.DrawMode = DrawMode.OwnerDrawFixed
cb.DrawItem -= Cb_DrawItem
cb.DrawItem += Cb_DrawItem
cb.DropDownClosed -= Cb_DropDownClosed
cb.DropDownClosed += Cb_DropDownClosed
End If
End Sub
事件以设置ToolTip值并显示它。我们将使用反射从下拉项中获取DrawItem属性，并将其字符串值设置为工具提示。
description处理ComboBox Private Sub Cb_DrawItem(sender As Object, e As DrawItemEventArgs)
Dim cb As ComboBox = TryCast(sender, ComboBox)
Dim item = cb.Items(e.Index)
Dim display As String = cb.GetItemText(item)
Dim toolText As String = item.[GetType]().GetProperty("description").GetValue(item, Nothing).ToString()
e.DrawBackground()
Using br As New SolidBrush(e.ForeColor)
e.Graphics.DrawString(display, e.Font, br, e.Bounds)
End Using
If (e.State And DrawItemState.Focus) = DrawItemState.Focus AndAlso cb.DroppedDown Then
Me.toolTip1.Show(toolText, cb, e.Bounds.Right, e.Bounds.Bottom, 2000)
End If
e.DrawFocusRectangle()
End Sub
事件以隐藏工具提示。
DropDownClosed