问题描述
我想要一个基于 datagridviewcolumn 类的自定义类的自定义属性。我想要一个属性,它是一个 datagridvewcolumns 列表,我希望能够在设计时选择列。实现这一目标的好方法是什么?我觉得我让这件事变得比需要的更复杂。
这是我到目前为止所做的。 我可以成功地创建一个属性,它是一个单一的 datagridviewcolumn,它提供了一个下拉菜单,可以在设计时使用自定义 objectselectoreditor 从可用列中进行选择,并覆盖 filltreewithdata 函数以使用表单中的所有 datagridviewcolumns 填充列表。但是,我无法扩展此属性以使用列列表的属性。默认编辑器会打开一个集合编辑器,然后创建一个新的 datagridviewcolumn 条目,其中包含所有 datagridviewcolumn 属性,而不仅仅是从列表中选择的下拉列表。
我得到的最接近的是创建一个从集合对象编辑器继承的自定义编辑器。然后,编辑器使用具有 datagridviewcolumn 属性的“自定义类”,该属性使用 objectselectoreditor,然后为集合中的每个新条目提供可供选择的列表。 此时,我收到错误消息,指出它无法将“自定义类”转换为 datagridviewcolumn。所以我试图覆盖 getitems 和 setitems 函数,这样编辑器将返回自定义类项的 datagridviewcolumn 属性的列表。此时我在构建解决方案时遇到一个错误,即 datagridviewcolumn 对象未标记为可序列化。
''' <summary>
''' A List of specific DGVColumns from the associated Datagridview Control.
''' </summary>
''' <returns></returns>
<Editor(GetType(MyDataGridViewColumnListEditor),GetType(Drawing.Design.UITypeEditor))>
Public Property TestDGVColList As List(Of DataGridViewColumn)
Get
Return lstTestDGVColList
End Get
Set(value As List(Of DataGridViewColumn))
lstTestDGVColList = value
End Set
End Property
编辑器代码
Inherits CollectionEditor
<browsable(False),Editorbrowsable(EditorbrowsableState.Never),DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)>
Public Property CurrentDataGridViewColumn As DataGridViewColumn
Public Sub New()
MyBase.New(type:=GetType(List(Of SelectedDataGridViewColumnItem)))
End Sub
Public Overrides Function EditValue(context As ITypeDescriptorContext,provider As IServiceProvider,value As Object) As Object
CurrentDataGridViewColumn = context.Instance.datagridviewcolumn
Return MyBase.EditValue(context,provider,value)
End Function
Protected Overrides Function GetItems(editValue As Object) As Object()
Dim lst As New List(Of Object)
If editValue IsNot nothing Then
For Each sdgvci As DataGridViewColumn In editValue
lst.Add(New SelectedDataGridViewColumnItem With {.CurrentDataGridViewColumn = CurrentDataGridViewColumn,.DataGridViewColumn = sdgvci})
Next
Return lst.ToArray
Else
Return MyBase.GetItems(editValue)
End If
End Function
Protected Overrides Function SetItems(editValue As Object,value() As Object) As Object
Dim lst As New List(Of DataGridViewColumn)
For Each sdgvci As SelectedDataGridViewColumnItem In value
lst.Add(sdgvci.DataGridViewColumn)
Next
Return lst
End Function
Protected Overrides Function CreateInstance(itemType As Type) As Object
Dim obj As Object = MyBase.CreateInstance(itemType)
CType(obj,SelectedDataGridViewColumnItem).CurrentDataGridViewColumn = CurrentDataGridViewColumn
Return obj
End Function
Class SelectedDataGridViewColumnItem
<Editor(GetType(MyDataGridViewColumnSelectionEditor),GetType(Drawing.Design.UITypeEditor))>
Public Property DataGridViewColumn As DataGridViewColumn
<browsable(False),DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)>
Public Property CurrentDataGridViewColumn As DataGridViewColumn
Sub New()
End Sub
End Class
End Class
Public Class MyDataGridViewColumnSelectionEditor
Inherits ObjectSelectorEditor
Protected Overrides Sub FillTreeWithData(ByVal theSel As Selector,ByVal theCtx As ITypeDescriptorContext,ByVal theProvider As IServiceProvider)
MyBase.FillTreeWithData(theSel,theCtx,theProvider)
Dim dgvcType As Type = GetType(DataGridViewColumn)
Try
For Each dgvcol As DataGridViewColumn In CType(theCtx.Instance.CurrentDataGridViewColumn.datagridview,DataGridView).Columns
If dgvcType.IsAssignableFrom(dgvcol.GetType) Then
Try
Dim [aNd] As SelectorNode = New SelectorNode(dgvcol.HeaderText & " - " & dgvcol.Name,dgvcol)
theSel.Nodes.Add([aNd])
theSel.sort()
Catch ex As Exception
End Try
End If
Next
Catch ex As Exception
End Try
End Sub
End Class
解决方法
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