本文由机器翻译。若要查看英语原文,请勾选“英语”复选框。 也可将鼠标指针移到文本上,在弹出窗口中显示英语原文。
翻译
英语

CancelEventArgs 类

 

为可取消的事件提供数据。

命名空间:   System.ComponentModel
程序集:  System(位于 System.dll)

System.Object
  System.EventArgs
    System.ComponentModel.CancelEventArgs
      Microsoft.VisualBasic.ApplicationServices.StartupEventArgs
      System.ComponentModel.DoWorkEventArgs
      System.Configuration.SettingChangingEventArgs
      System.Drawing.Printing.PrintEventArgs
      System.IdentityModel.Services.ErrorEventArgs
      System.IdentityModel.Services.RedirectingToIdentityProviderEventArgs
      System.IdentityModel.Services.SecurityTokenReceivedEventArgs
      System.IdentityModel.Services.SecurityTokenValidatedEventArgs
      System.IdentityModel.Services.SessionSecurityTokenReceivedEventArgs
      System.Web.ModelBinding.ModelValidatingEventArgs
      System.Web.UI.WebControls.DetailsViewDeleteEventArgs
      System.Web.UI.WebControls.DetailsViewInsertEventArgs
      System.Web.UI.WebControls.DetailsViewModeEventArgs
      System.Web.UI.WebControls.DetailsViewPageEventArgs
      System.Web.UI.WebControls.DetailsViewUpdateEventArgs
      System.Web.UI.WebControls.EntityDataSourceChangingEventArgs
      System.Web.UI.WebControls.EntityDataSourceContextDisposingEventArgs
      System.Web.UI.WebControls.EntityDataSourceSelectingEventArgs
      System.Web.UI.WebControls.FormViewDeleteEventArgs
      System.Web.UI.WebControls.FormViewInsertEventArgs
      System.Web.UI.WebControls.FormViewModeEventArgs
      System.Web.UI.WebControls.FormViewPageEventArgs
      System.Web.UI.WebControls.FormViewUpdateEventArgs
      System.Web.UI.WebControls.GridViewCancelEditEventArgs
      System.Web.UI.WebControls.GridViewDeleteEventArgs
      System.Web.UI.WebControls.GridViewEditEventArgs
      System.Web.UI.WebControls.GridViewPageEventArgs
      System.Web.UI.WebControls.GridViewSelectEventArgs
      System.Web.UI.WebControls.GridViewSortEventArgs
      System.Web.UI.WebControls.GridViewUpdateEventArgs
      System.Web.UI.WebControls.LinqDataSourceDeleteEventArgs
      System.Web.UI.WebControls.LinqDataSourceDisposeEventArgs
      System.Web.UI.WebControls.LinqDataSourceInsertEventArgs
      System.Web.UI.WebControls.LinqDataSourceSelectEventArgs
      System.Web.UI.WebControls.LinqDataSourceUpdateEventArgs
      System.Web.UI.WebControls.ListViewCancelEventArgs
      System.Web.UI.WebControls.ListViewDeleteEventArgs
      System.Web.UI.WebControls.ListViewEditEventArgs
      System.Web.UI.WebControls.ListViewInsertEventArgs
      System.Web.UI.WebControls.ListViewSelectEventArgs
      System.Web.UI.WebControls.ListViewSortEventArgs
      System.Web.UI.WebControls.ListViewUpdateEventArgs
      System.Web.UI.WebControls.ObjectDataSourceDisposingEventArgs
      System.Web.UI.WebControls.ObjectDataSourceFilteringEventArgs
      System.Web.UI.WebControls.ObjectDataSourceMethodEventArgs
      System.Web.UI.WebControls.SqlDataSourceCommandEventArgs
      System.Web.UI.WebControls.SqlDataSourceFilteringEventArgs
      System.Web.UI.WebControls.WebParts.WebPartCancelEventArgs
      System.Web.UI.WebControls.WebParts.WebPartConnectionsCancelEventArgs
      System.Web.UI.WebControls.WebParts.WebPartDisplayModeCancelEventArgs
      System.Windows.Controls.InkCanvasSelectionChangingEventArgs
      System.Windows.Controls.InkCanvasSelectionEditingEventArgs
      System.Windows.Controls.InkCanvasStrokeErasingEventArgs
      System.Windows.Forms.BindingCompleteEventArgs
      System.Windows.Forms.ColumnReorderedEventArgs
      System.Windows.Forms.ColumnWidthChangingEventArgs
      System.Windows.Forms.DataGridViewCellCancelEventArgs
      System.Windows.Forms.DataGridViewCellValidatingEventArgs
      System.Windows.Forms.DataGridViewRowCancelEventArgs
      System.Windows.Forms.DpiChangedEventArgs
      System.Windows.Forms.FormClosingEventArgs
      System.Windows.Forms.InputLanguageChangingEventArgs
      System.Windows.Forms.PopupEventArgs
      System.Windows.Forms.SplitterCancelEventArgs
      System.Windows.Forms.TabControlCancelEventArgs
      System.Windows.Forms.ToolStripDropDownClosingEventArgs
      System.Windows.Forms.TreeViewCancelEventArgs
      System.Windows.Forms.WebBrowserNavigatingEventArgs
      System.Windows.Navigation.NavigatingCancelEventArgs
      System.Windows.SessionEndingCancelEventArgs

[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)]
public class CancelEventArgs : EventArgs

名称说明
System_CAPS_pubmethodCancelEventArgs()

新实例初始化 CancelEventArgsCancel 属性设置为 false

System_CAPS_pubmethodCancelEventArgs(Boolean)

新实例初始化 CancelEventArgsCancel 属性设置为给定的值。

名称说明
System_CAPS_pubpropertyCancel

获取或设置一个值,该值指示是否应取消事件。

名称说明
System_CAPS_pubmethodEquals(Object)

确定指定的对象是否等于当前对象。(继承自 Object。)

System_CAPS_protmethodFinalize()

在垃圾回收将某一对象回收前允许该对象尝试释放资源并执行其他清理操作。(继承自 Object。)

System_CAPS_pubmethodGetHashCode()

作为默认哈希函数。(继承自 Object。)

System_CAPS_pubmethodGetType()

获取当前实例的 Type(继承自 Object。)

System_CAPS_protmethodMemberwiseClone()

创建当前 Object 的浅表副本。(继承自 Object。)

System_CAPS_pubmethodToString()

返回表示当前对象的字符串。(继承自 Object。)

A cancelable event is raised by a component when it is about to perform an action that can be canceled, such as the E:System.Windows.Forms.Form.Closing event of a T:System.Windows.Forms.Form.

System_CAPS_note说明

The E:System.Windows.Forms.Form.Closing event is deprecated and has been replaced by E:System.Windows.Forms.Form.FormClosing. It is offered as an example here only to illustrate the usage of T:System.ComponentModel.CancelEventArgs.

CancelEventArgs provides the Cancel property to indicate whether the event should be canceled.

The following example uses T:System.ComponentModel.CancelEventArgs and a T:System.ComponentModel.CancelEventHandler to handle the E:System.Windows.Forms.Form.Closing event of a T:System.Windows.Forms.Form. This code assumes that you have created a T:System.Windows.Forms.Form with a class-level T:System.Boolean variable named isDataSaved. It also assumes that you have added a statement to invoke the OtherInitialize method from the form's E:System.Windows.Forms.Form.Load method or the constructor (after the call to InitializeComponent).

// Call this method from the constructor of your form
    private void OtherInitialize() {
       this.Closing += new CancelEventHandler(this.Form1_Closing);
       // Exchange commented line and note the difference.
       this.isDataSaved = true;
       //this.isDataSaved = false;
    }

    private void Form1_Closing(Object sender, CancelEventArgs e) {
       if (!isDataSaved) {
          e.Cancel = true;
          MessageBox.Show("You must save first.");
       }
       else {
          e.Cancel = false;
          MessageBox.Show("Goodbye.");
       }
    }

通用 Windows 平台
自 8 起可用
.NET Framework
自 1.1 起可用
可移植类库
可移植 .NET 平台 中受支持
Silverlight
自 3.0 起可用
Windows Phone Silverlight
自 7.0 起可用
Windows Phone
自 8.1 起可用

此类型的所有公共静态(Visual Basic 中的 已共享 在 Visual Basic 中)成员都是线程安全的。不保证所有实例成员都是线程安全的。

返回页首
显示: