如何在WinForms选项卡控件中指出要从哪个选项卡移动到哪个选项卡？
我需要确定用户来自哪个选项卡，以及切换选项卡时可能取消切换的选项卡。 我尝试了取消选择，取消选择，选择，选择的事件，并且所有这些事件都显示e.TabPageIndex与sender.SelectedIndex相同。
是否存在我可以使用的事件或属性，以便我可以确定其中的两个方面，或者我是否必须通过从一个事件缓存它并在新事件中使用该值来破解某些内容。
我试图避免处理取消选择/取消选择的事件并缓存要在选择事件中使用的值。 我已经知道我可以做到这一点，所以我问是否有一种更清洁的方式，而不是这样做。
我已经在C＃和VB中尝试过，结果相同（毫不奇怪）。
谢谢。
它看起来不像任何一个事件参数将包含前一个和当前选项卡的详细信息，因此您需要处理几个事件以跟踪。
至少，您需要使用Deselected事件来存储对先前选择的选项卡的引用。 您始终可以在TabControl中查询其当前选项卡。 要进一步拉伸，您还可以处理Selected事件以跟踪当前选项卡。
Option Strict On Option Explicit On Public Class Form1 Private PreviousTab As TabPage Private CurrentTab As TabPage Private Sub TabControl1_Deselected(ByVal sender As Object, ByVal e As System.Windows.Forms.TabControlEventArgs) Handles TabControl1.Deselected PreviousTab = e.TabPage Debug.WriteLine("Deselected: " + e.TabPage.Name) End Sub Private Sub TabControl1_Selected(ByVal sender As Object, ByVal e As System.Windows.Forms.TabControlEventArgs) Handles TabControl1.Selected CurrentTab = e.TabPage Debug.WriteLine("Selected: " + e.TabPage.Name) End Sub Private Sub TabControl1_Selecting(ByVal sender As Object, ByVal e As System.Windows.Forms.TabControlCancelEventArgs) Handles TabControl1.Selecting If CurrentTab Is Nothing Then Return Debug.WriteLine(String.Format("Proposed change from {0} to {1}", CurrentTab.Name, e.TabPage.Name)) End Sub End Class
我相信选择事件中的e.Cancel标志应该这样做。 这会在取消时将所选标签发送回原始标签：
private void tabControl1_Selecting( object sender, TabControlCancelEventArgs e ) { int badIndex = 0; if ( tabControl1.SelectedIndex == badIndex ) e.Cancel = true; }
如果您确实需要更复杂的行为，则可以使用制表符控件的子类，然后覆盖onSelecting方法。 这不应该轻易做到。 如果将来更改控件，您将破坏代码。 并且您必须确认是否满足选项卡控件的所有行为（即构造函数…）
编辑：根据反馈。 这将在选择之前在内部跟踪原始选项卡。
public class MyTab : System.Windows.Forms.TabControl { int _previousTab; protected override void OnSelecting( TabControlCancelEventArgs e ) { // Some logic here to do cool UI things, perhaps use _previousTab // Call the base method base.OnSelecting( e ); } protected override void OnDeselecting( TabControlCancelEventArgs e ) { // Store the value for use later in the chain of events _previousTab = this.SelectedIndex; // Call the base method base.OnDeselecting( e ); } }
您可以订阅TabControl.Deselecting 。 当它触发时，事件args中的选项卡索引将是旧索引。
然后，您可以订阅TabControl.Selected 。 触发此事件时，选项卡索引将是新选择的选项卡的索引。
你可以这样做：
private int _oldIndex = -1; private void tabControl1_Deselected(object sender, TabControlEventArgs e) { _oldIndex = e.TabPageIndex; } private void tabControl1_Selecting(object sender, TabControlCancelEventArgs e) { if (_oldIndex != -1) { if (CanChangeTab(_oldIndex, e.TabPageIndex)) { e.Cancel = true; } } } private bool CanChangeTab(int fromIndex, int toIndex) { // Put your logic here }
您可以使用Deselecting事件获取用户正在远离的选项卡的索引，并将其存储在变量中以供以后使用：
Private Sub TabControl1_Deselecting(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TabControlCancelEventArgs) Handles TabControl1.Deselecting someClassLevelVariable = e.TabPageIndex End Sub
您希望使用代码来阻止选择事件中的切换。 这是VB.NET中的一个示例，它将阻止您在选项卡控件上选择选项卡2：
Private Sub TabControl1_Selecting(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TabControlCancelEventArgs) Handles TabControl1.Selecting If (e.TabPageIndex = 1) Then e.Cancel = True End If End Sub
为我的初始答案提供替代….这是一个扩展TabControl的示例，它修改事件参数以包含更多细节。
免责声明这是打耳光的，它肯定需要一些调整！
Option Strict On Option Explicit On Imports System Imports System.Windows.Forms Public Class ExtendedTabControl Inherits TabControl Public Shadows Event Selecting As EventHandler(Of SelectedTabChangingEventArgs) Public Shadows Event Selected As EventHandler(Of SelectedTabChangedEventArgs) Private _PreviousTab As TabPage Public Property PreviousTab() As TabPage Get Return _PreviousTab End Get Private Set(ByVal value As TabPage) _PreviousTab = value End Set End Property Private _CurrentTab As TabPage Public Property CurrentTab() As TabPage Get Return _CurrentTab End Get Private Set(ByVal value As TabPage) _CurrentTab = value End Set End Property Protected Overrides Sub OnDeselected(ByVal e As System.Windows.Forms.TabControlEventArgs) PreviousTab = e.TabPage MyBase.OnDeselected(e) End Sub Protected Overrides Sub OnSelected(ByVal e As System.Windows.Forms.TabControlEventArgs) CurrentTab = e.TabPage Dim selectedArgs As New SelectedTabChangedEventArgs(e, PreviousTab) RaiseEvent Selected(Me, selectedArgs) End Sub Protected Overrides Sub OnSelecting(ByVal e As System.Windows.Forms.TabControlCancelEventArgs) Dim selectedArgs As New SelectedTabChangingEventArgs(e, CurrentTab) RaiseEvent Selecting(Me, selectedArgs) End Sub End Class Public Class SelectedTabChangingEventArgs Inherits TabControlCancelEventArgs Public Sub New(ByVal selectingEventArgs As TabControlCancelEventArgs, ByVal previousTabPage As TabPage) MyBase.New(selectingEventArgs.TabPage, selectingEventArgs.TabPageIndex, selectingEventArgs.Cancel, selectingEventArgs.Action) Me.CurrentTab = previousTabPage End Sub Private _CurrentTab As TabPage Public Property CurrentTab() As TabPage Get Return _CurrentTab End Get Set(ByVal value As TabPage) _CurrentTab = value End Set End Property End Class Public Class SelectedTabChangedEventArgs Inherits TabControlEventArgs Public Sub New(ByVal selectedEventArgs As TabControlEventArgs, ByVal previousTabPage As TabPage) MyBase.New(selectedEventArgs.TabPage, selectedEventArgs.TabPageIndex, selectedEventArgs.Action) Me.PreviousTab = previousTabPage End Sub Private _PreviousTab As TabPage Public Property PreviousTab() As TabPage Get Return _PreviousTab End Get Set(ByVal value As TabPage) _PreviousTab = value End Set End Property End Class
…以及使用此控件的示例表单…
Option Strict On Option Explicit On Public Class Form1 Private Sub TabControl1_Selecting(ByVal sender As Object, ByVal e As SelectedTabChangingEventArgs) Handles TabControl1.Selecting If e.CurrentTab Is Nothing Then Return Console.WriteLine(String.Format("Proposed change from {0} to {1}", e.CurrentTab.Name, e.TabPage.Name)) End Sub Private Sub TabControl1_Selected(ByVal sender As Object, ByVal e As SelectedTabChangedEventArgs) Handles TabControl1.Selected Console.WriteLine(String.Format("Changed from {0} to {1}", e.PreviousTab.Name, e.TabPage.Name)) End Sub End Class
tabControl有一个非公共成员“lastSelection”，它包含您想要的信息。 不幸的是，我没有办法达到目的。 当他们拥有你想要的但却不让你使用它时，这是非常令人沮丧的。
在Deselect_Event中尝试这个：
private void tabControl1_Deselected(object sender, TabControlEventArgs e) { var test = e.TabPage.Text; }