在执行操作时访问当前选定的对象

　　无论操作类型如何，传递给事件的参数都包括SimpleActionExecuteEventArgs.CurrentObject和SimpleActionExecuteEventArgs.SelectedObjects属性。CurrentObject属性，指定当前的活动对象；SelectedObjects是在活动视图中选择的对象的集合。

　　以下代码针对联系人进行操作（点击事件）。该操作执行时，它将向选中的对象（列表视图（ListView）中选中的对象或者详细视图（DetailView）所对应的对象）Note添加一行显示信息。

 1 using System;
 2 using System.Collections;
 3 using DevExpress.ExpressApp;
 4 using DevExpress.ExpressApp.Actions;
 5 using DevExpress.ExpressApp.EF;
 6 //... 
 7 public partial class MyNotesController : ViewController {
 8     public MyNotesController() {
 9         SimpleAction myAction = new SimpleAction(this, "Salary Info", "Edit");
10         myAction.SelectionDependencyType = SelectionDependencyType.RequireMultipleObjects;
11         myAction.TargetObjectType = typeof(Contact);
12         myAction.Execute += myAction_Execute;
13         Actions.Add(myAction);
14     }
15     void myAction_Execute(object sender, SimpleActionExecuteEventArgs e) {
16         ArrayList SelectedContacts = new ArrayList();
17         if ((e.SelectedObjects.Count > 0) && 
18             ((e.SelectedObjects[0] is XafDataViewRecord) || (e.SelectedObjects[0] is XafInstantFeedbackRecord))) {
19             foreach (var selectedObject in e.SelectedObjects) {
20                 SelectedContacts.Add((Contact)ObjectSpace.GetObject(selectedObject));
21             }
22         }
23         else {
24             SelectedContacts = (ArrayList)e.SelectedObjects;
25         }
26         foreach (Contact selectedContact in SelectedContacts) {
27             DateTime now = DateTime.Now;
28             selectedContact.Notes += "
[INFO] Your salary is transfered " + 
29                 now.ToString("M/d/yy") + " at " + now.ToString("hh:mm");
30         }
31         ObjectSpace.CommitChanges();
32         ObjectSpace.Refresh();
33     }
34 }

使用视图控制器访问当前选定的对象

　　一种不太常见的任务是，从控制器访问视图的焦点和选定对象。在本例中，使用ViewController.View属性指定的视图对象的View.CurrentObject和View.SelectedObjects属性。CurrentObject属性，指定当前的活动对象；SelectedObjects是在活动视图中选择的对象的集合。

　　下面的代码片段演示了一个用于联系人详细信息视图的控制器。如果您要删除一个联系人，那么将被删除的联系人的全名将添加到confirm消息中。如果您想删除多个联系人，则将添加所选联系人计数。

 1 public class MyConfirmationController : ViewController {
 2     private string defaultMessage;
 3     DeleteObjectsViewController deleteObjectsViewController;
 4     public MyConfirmationController() {
 5         this.TargetObjectType = typeof(Contact);
 6     }
 7     protected override void OnActivated() {
 8         base.OnActivated();
 9         deleteObjectsViewController = Frame.GetController<DeleteObjectsViewController>();
10         if (deleteObjectsViewController != null) {
11             defaultMessage = deleteObjectsViewController.DeleteAction.GetFormattedConfirmationMessage();
12             View.SelectionChanged += View_SelectionChanged;
13             UpdateConfirmationMessage();                
14         }
15     }
16     void View_SelectionChanged(object sender, System.EventArgs e) {
17         UpdateConfirmationMessage();
18     }
19     private void UpdateConfirmationMessage() {
20         if (View.SelectedObjects.Count == 1) {
21             deleteObjectsViewController.DeleteAction.ConfirmationMessage =
22                 String.Format("You are about to delete the '{0}' Contact. Do you want to proceed?",
23                 ((Contact)View.CurrentObject).FullName);
24         }
25         else {
26             deleteObjectsViewController.DeleteAction.ConfirmationMessage =
27                 String.Format("You are about to delete {0} Contacts. Do you want to proceed?",
28                 (View.SelectedObjects.Count));
29         }
30     }
31     protected override void OnDeactivated() {
32         base.OnDeactivated();
33         if (deleteObjectsViewController != null) {
34             View.SelectionChanged -= View_SelectionChanged;
35             deleteObjectsViewController.DeleteAction.ConfirmationMessage = defaultMessage;
36             deleteObjectsViewController = null;
37         }
38     }
39 }

View Code

　　注：当视图在详细视图（DataView）模式运行时，View.CurrentObject 和 View.SelectedObjects 返回的是XafDataViewRecord对象，而不是原始业务对象。要获得原始的对象，使用View.ObjectSpace.GetObject(obj)方法

参考网址

[1] https://documentation.devexpress.com/eXpressAppFramework/113324/Task-Based-Help/Views/How-to-Access-Objects-Selected-in-the-Current-View

[2]官方项目源码：http://www.devexpress.com/example=E3016