DevExpress XAF 查找列表視圖及聯(lián)級過濾

　　主要通過列表視圖，實現(xiàn)聯(lián)級過濾。只是對官方文件做了簡單的代碼復制，以后有機會再整理和修改。

初始化實現(xiàn)

　　使用the DataSourcePropertyAttribute 和 DataSourceCriteriaAttribute實現(xiàn)聯(lián)級過濾。

 1 using System.ComponentModel;
 2 using DevExpress.Data.Filtering;
 3 //... 
 4 [DefaultClassOptions]
 5 public class Order : BaseObject {
 6    public Order(Session session) : base(session) { }
 7    private Product product;
 8    public Product Product {
 9       get {
10          return product;
11       }
12       set {
13          SetPropertyValue("Product", ref product, value);
14       }
15    }
16    private Accessory accessory;
17    public Accessory Accessory {
18       get {
19          return accessory;
20       }
21       set {
22          SetPropertyValue("Accessory", ref accessory, value);
23       }
24    }
25 }
26 public class Product : BaseObject {
27    public Product(Session session) : base(session) { }
28    private String productName;
29    public String ProductName {
30       get { 
31          return productName;
32       }
33       set {
34          SetPropertyValue("ProductName", ref productName, value);
35       }
36    }
37    [Association("P-To-C")]
38    public XPCollection<Accessory> Accessories {
39       get { return GetCollection<Accessory>("Accessories"); }
40    }
41 }
42 public class Accessory : BaseObject {
43    public Accessory(Session session) : base(session) { }
44    private String accessoryName;
45    public String AccessoryName {
46       get { 
47          return accessoryName; 
48       }
49       set {
50          SetPropertyValue("AccessoryName", ref accessoryName, value);
51       }
52    }
53    private bool isGlobal;
54    public bool IsGlobal {
55       get {
56          return isGlobal;
57       }
58       set {
59          SetPropertyValue("IsGlobal", ref isGlobal, value);
60       }
61    }
62    private Product product;
63    [Association("P-To-C")]
64    public Product Product { 
65       get {
66          return product;
67       } 
68       set {
69          SetPropertyValue("Product", ref product, value);
70       } 
71    }
72 }

　　效果下圖。

場景1 -使用指定集合屬性中的對象填充查找

　　關鍵代碼：[DataSourceProperty("Product.Accessories")]

 1 [DefaultClassOptions]
 2 public class Order : BaseObject {
 3    // ... 
 4    [DataSourceProperty("Product.Accessories")]
 5    public Accessory Accessory {
 6       get {
 7          return accessory;
 8       }
 9       set {
10          SetPropertyValue("Accessory", ref accessory, value);
11       }
12    }
13 }

　　效果如下圖：

場景2 -為Lookup屬性集合應用標準

 1 [DefaultClassOptions]
 2 public class Order : BaseObject {
 3    // ... 
 4    [DataSourceCriteria("IsGlobal = true")]
 5    public Accessory Accessory {
 6       get {
 7          return accessory;
 8       }
 9       set {
10          SetPropertyValue("Accessory", ref accessory, value);
11       }
12    }
13 }
14 public class Accessory : BaseObject {
15       // ... 
16    private bool isGlobal;
17    public bool IsGlobal {
18       get { return isGlobal; }
19       set { 
20          SetPropertyValue("IsGlobal", ref isGlobal, value);      
21       }
22    }
23 }

場景3 -如果指定的數(shù)據(jù)源屬性為空，則使用備用標準

 1 [DefaultClassOptions]
 2 public class Order : BaseObject {
 3    // ... 
 4    [DataSourceProperty("Product.Accessories", 
 5       DataSourcePropertyIsNullMode.CustomCriteria, "IsGlobal = true")]
 6    public Accessory Accessory {
 7       get {
 8          return accessory;
 9       }
10       set {
11          SetPropertyValue("Accessory", ref accessory, value);
12       }
13    }
14 }

場景4 -手動填充查找

[DefaultClassOptions]
public class Order : BaseObject {
   // ... 
   // Set the AvailableAccessories collection as a data source for the Accessory property 
   [DataSourceProperty("AvailableAccessories")] 
   public Accessory Accessory {
      get {return accessory;}
      set {
         SetPropertyValue("Accessory", ref accessory, value);
      }
   }
   private XPCollection<Accessory> availableAccessories;
   [Browsable(false)] // Prohibits showing the AvailableAccessories collection separately 
   public XPCollection<Accessory> AvailableAccessories {
      get {
         if(availableAccessories == null) {
            // Retrieve all Accessory objects 
            availableAccessories = new XPCollection<Accessory>(Session);
            // Filter the retrieved collection according to current conditions 
            RefreshAvailableAccessories();
         }
         // Return the filtered collection of Accessory objects 
         return availableAccessories;
      }
   }
   private void RefreshAvailableAccessories() {
      if(availableAccessories == null)
         return;
      // Process the situation when the Product is not specified (see the Scenario 3 above) 
      if(Product == null) {
         // Show only Global Accessories when the Product is not specified 
         availableAccessories.Criteria = CriteriaOperator.Parse("[IsGlobal] = true");
      }
      else {
         // Leave only the current Product's Accessories in the availableAccessories collection 
         availableAccessories.Criteria = new BinaryOperator("Product", Product);
         if(IncludeGlobalAccessories == true) {
            // Add Global Accessories 
            XPCollection<Accessory> availableGlobalAccessories = 
               new XPCollection<Accessory>(Session);
            availableGlobalAccessories.Criteria = CriteriaOperator.Parse("[IsGlobal] = true");
            availableAccessories.AddRange(availableGlobalAccessories);
         }
      }
      // Set null for the Accessory property to allow an end-user  
      //to set a new value from the refreshed data source 
      Accessory = null;
   }
   public Product Product {
      get {return product;}
      set {
         SetPropertyValue("Product", ref product, value);
         // Refresh the Accessory Property data source 
         RefreshAvailableAccessories();
      }
   }
   private bool includeGlobalAccessories;
   [ImmediatePostData] //Use this attribute to refresh the Accessory  
   public bool IncludeGlobalAccessories {
      get {return includeGlobalAccessories;}
      set {
         if(includeGlobalAccessories != value) {
            includeGlobalAccessories = value;
            if(!IsLoading) {
               // Refresh the Accessory Property data source                     
               RefreshAvailableAccessories();
               SetPropertyValue("IncludeGlobalAccessories", ref includeGlobalAccessories, value);
            }
         }
      }
   }
}

場景5 -根據(jù)當前對象的屬性篩選Lookup屬性集合

 1 using DevExpress.Persistent.Base;
 2 using DevExpress.Persistent.BaseImpl;
 3 // ... 
 4 public class Contact : Person {
 5     // ... 
 6     [DataSourceProperty("Department.Contacts", DataSourcePropertyIsNullMode.SelectAll)]
 7     [DataSourceCriteria("Position.Title = 'Manager' AND Oid != '@This.Oid'")]
 8     public Contact Manager {
 9         get {
10             return manager;
11         }
12         set {
13             SetPropertyValue("Manager", ref manager, value);
14         }
15     }
16     // ... 
17 }

參考網(wǎng)址

　　[1] https://documentation.devexpress.com/eXpressAppFramework/112681/Task-Based-Help/Filtering/How-to-Implement-Cascading-Filtering-for-Lookup-List-Views

posted @ 2019-09-05 14:05 陸陸無為而治者閱讀(657) 評論(0) 收藏舉報

刷新頁面返回頂部

lyj00436