從webservices填充datagrid

我想編程一個Silverlight應用程序（使用Silverlight 5.1，.Net 4.5），我想要有3個數據網格。從webservices填充datagrid

第一個數據網格顯示症狀列表，第二個數據網格應列出datagrid1中所選症狀的子症狀，第三個數據網格應顯示一種「鹽」來治療子代症狀。數據網格應通過WCF Web服務接收他們的數據。第一個數據網格從表格症狀中獲取所有數據，第二個數據網格僅從webservice獲取datagrid1中所選症狀的子節奏，而「salt」數據網格只應接收來自web服務的選定症狀和子節奏的salt。

只要我選擇了一種症狀，就會出現subsymtpoms，只要我選擇了症狀，就會出現相應的鹽。一切都很好。

我遇到的問題：當我選擇一個subsymptom並且再次選擇Datagrid1中的一個症狀時，所有的datagrids消失。

下面是代碼：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
using System.ServiceModel; 
using Rebat.SymptomeService; 


namespace Rebat 
{ 
    public partial class MainPage : UserControl 
    { 
     ServiceClient client = new ServiceClient(); 

     public MainPage() 
     { 
      InitializeComponent(); 
      ServiceClient client = new ServiceClient(); 
      client.SymptomeListCompleted += new EventHandler<SymptomeListCompletedEventArgs>(client_SymptomeListCompleted); 
      client.SymptomeListAsync(); 
     } 

     void client_SymptomeListCompleted(object sender, SymptomeListCompletedEventArgs e) 
     { 
      SymptomeGrid.ItemsSource = e.Result; 
     } 
     void client_CustomerListCompleted(object sender, Symptome2ListCompletedEventArgs e) 
     { 
      Symptome2Grid.ItemsSource = e.Result; 
     } 
     void client_SalzListCompleted(object sender, SalzListCompletedEventArgs e) 
     { 
      SalzGrid.ItemsSource = e.Result; 
     } 

     private void SymptomeGrid_SelectionChanged(object sender, SelectionChangedEventArgs e) 
     { 
      Symptome sympt = SymptomeGrid.SelectedItem as Symptome; 
      client.Symptome2ListCompleted += new EventHandler<Symptome2ListCompletedEventArgs>(client_CustomerListCompleted); 
      client.Symptome2ListAsync(sympt.sId.ToString()); 
     } 

     private void Symptome2Grid_SelectionChanged(object sender, SelectionChangedEventArgs e) 
     { 
      Symptome2 sympt2 = Symptome2Grid.SelectedItem as Symptome2; 
      client.SalzListCompleted += new EventHandler<SalzListCompletedEventArgs>(client_SalzListCompleted); 
      //if i remove the next line, datagrids don't dissapear anymore... so this might be the problem 
      client.SalzListAsync(sympt2.sy1.ToString(), sympt2.sy2.ToString()); 
     } 

    } 
}

這裏的.xaml代碼

<UserControl 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk" x:Class="Rebat.MainPage" 
    mc:Ignorable="d" 
    d:DesignHeight="300" d:DesignWidth="400"> 

    <Grid x:Name="LayoutRoot" Background="White" Margin="-13,0,-543,-335" RenderTransformOrigin="0.499,0.573"> 
     <Grid.RowDefinitions> 
      <RowDefinition Height="0*"/> 
      <RowDefinition Height="516*"/> 
      <RowDefinition Height="119*"/> 
     </Grid.RowDefinitions> 

     <sdk:DataGrid x:Name="SymptomeGrid" Margin="20,10,0,0" HorizontalAlignment="Left" Width="249" Grid.RowSpan="2" SelectionChanged="SymptomeGrid_SelectionChanged" Height="227" VerticalAlignment="Top"/> 
     <sdk:DataGrid x:Name="Symptome2Grid" HorizontalAlignment="Left" Height="227" Margin="293,10,0,0" VerticalAlignment="Top" Width="244" Grid.RowSpan="2" SelectionChanged="Symptome2Grid_SelectionChanged"/> 
     <sdk:DataGrid x:Name="SalzGrid" HorizontalAlignment="Left" Height="227" Margin="20,275,0,0" Grid.Row="1" VerticalAlignment="Top" Width="401"/> 

    </Grid> 
</UserControl>

，這裏的web服務代碼：

using System.ServiceModel; 
using System.ServiceModel.Activation; 
using System.Collections.Generic; 
using System.Data; 
using System.Data.SqlClient; 
using System.Data.OleDb; 

namespace Rebat.Web 
{ 
    [ServiceContract(Namespace = "")] 
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] 
    public class Service 
    { 
     [OperationContract] 
     public List<Symptome> SymptomeList() 
     { 
      var custList = new List<Symptome>(); 
      using (OleDbConnection conn = new OleDbConnection(
       @"Provider=Microsoft.ACE.OLEDB.12.0; Data Source = C:\Users\simon\Documents\Visual Studio 2012\Projects\WpfApplication1\WpfApplication1\rebat.mdb")) 
      { 
       const string sql = @"SELECT Feld1, Feld2 FROM Symptome"; 
       conn.Open(); 
       using (OleDbCommand cmd = new OleDbCommand(sql, conn)) 
       { 
        OleDbDataReader dr = cmd.ExecuteReader(
         CommandBehavior.CloseConnection); 
        if (dr != null) 
         while (dr.Read()) 
         { 
          var cust = new Symptome 
          { 
           sId = dr.GetInt16(0), 
           symptom = dr.GetString(1) 
          }; 
          custList.Add(cust); 
         } 
        return custList; 
       } 
      } 
     } 

     // Add more operations here and mark them with [OperationContract] 
     [OperationContract] 
     public List<Symptome2> Symptome2List(string s1) 
     { 
      var custList = new List<Symptome2>(); 
      using (OleDbConnection conn = new OleDbConnection(
       @"Provider=Microsoft.ACE.OLEDB.12.0; Data Source = C:\Users\simon\Documents\Visual Studio 2012\Projects\WpfApplication1\WpfApplication1\rebat.mdb")) 
      { 

       string sql = @"SELECT ID, sy1, sy2, symptom2 FROM Symptome2 where sy1="+s1; 
       conn.Open(); 
       using (OleDbCommand cmd = new OleDbCommand(sql, conn)) 
       { 
        OleDbDataReader dr = cmd.ExecuteReader(
         CommandBehavior.CloseConnection); 
        if (dr != null) 
         while (dr.Read()) 
         { 
          var cust = new Symptome2 
          { 
           ID = dr.GetInt32(0), 
           sy1 = dr.GetInt16(1), 
           sy2 = dr.GetInt16(2), 
           symptom2 = dr.GetString(3) 
          }; 
          custList.Add(cust); 
         } 
        return custList; 
       } 
      } 
     } 
     // Add more operations here and mark them with [OperationContract] 
     [OperationContract] 
     public List<Salz> SalzList(string sym1, string sym2) 
     { 
      var salzList = new List<Salz>(); 
      using (OleDbConnection conn = new OleDbConnection(
       @"Provider=Microsoft.ACE.OLEDB.12.0; Data Source = C:\Users\simon\Documents\Visual Studio 2012\Projects\WpfApplication1\WpfApplication1\rebat.mdb")) 
      { 

       string sql = @"SELECT sId, salz FROM Salze where sId in (SELECT saId from Rezept where sy1Id= " + sym1 + " and sy2Id=" +sym2 + ")"; 

       conn.Open(); 
       using (OleDbCommand cmd = new OleDbCommand(sql, conn)) 
       { 
        OleDbDataReader dr = cmd.ExecuteReader(
         CommandBehavior.CloseConnection); 
        if (dr != null) 
         while (dr.Read()) 
         { 
          var cust = new Salz 
          { 
           SID = dr.GetInt32(0), 
           Name = dr.GetString(1) 
          }; 
          salzList.Add(cust); 
         } 
        return salzList; 
       } 
      } 
     } 
    } 
}

終於幫助類

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 

namespace Rebat.Web 
{ 
    public class Symptome 
    { 
     public int sId { get; set; } 
     public string symptom { get; set; } 
    } 
} 

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 

namespace Rebat.Web 
{ 
    public class Symptome2 
    { 
     public int ID { get; set; } 
     public int sy1 { get; set; } 
     public int sy2 { get; set; } 
     public string symptom2 { get; set; } 
    } 
} 

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 

namespace Rebat.Web 
{ 
    public class Salz 
    { 
     public int SID { get; set; } 
     public string Name { get; set; } 
    } 
}

來源

2012-11-03 Simon

下面是完整的源代碼，試試這個

代碼behind.cs：

private void SymptomeGrid_SelectionChanged(object sender, SelectionChangedEventArgs e) 
    { 
     Symptome2Grid.ItemsSource = null; 
     SalzGrid.ItemsSource = null; 
     svcSymptom.Symptome sympt = SymptomeGrid.SelectedItem as svcSymptom.Symptome; 
     if (sympt != null) 
     { 
      svcSymptom.Service1Client SymptomsClient = new svcSymptom.Service1Client(); 

       SymptomsClient.Symptome2ListCompleted += (a, ae) => 
       { 
        if (ae.Result.Count != 0) 
        { 
         Symptome2Grid.ItemsSource = ae.Result.ToList(); 
        } 
       }; 
       SymptomsClient.Symptome2ListAsync(sympt.symptom.ToString()); 

     } 

    } 

    private void Symptome2Grid_SelectionChanged(object sender, SelectionChangedEventArgs e) 
    { 
     SalzGrid.ItemsSource = null; 
     svcSymptom.Symptome2 sympt2 = Symptome2Grid.SelectedItem as svcSymptom.Symptome2; 
     if (sympt2 != null) 
     { 
      svcSymptom.Service1Client SymptomsClient = new svcSymptom.Service1Client(); 
      SymptomsClient.SalzListCompleted += (a, ae) => 
       { 
        if (ae.Result.Count != 0) 
        { 
         SalzGrid.ItemsSource = ae.Result.ToList(); 
        } 
       }; 
      SymptomsClient.SalzListAsync(sympt2.sy1.ToString(), sympt2.sy2.ToString()); 

     } 
    }

來源

2012-11-08 18:38:15 Sajeetharan

但什麼是修復？原始代碼有什麼問題？ –

在第一個網格的選擇已更改的事件上，您需要清除其他兩個數據網格，對於第二個數據網格您需要清除第三個數據網格。您還必須檢查所選項目是否爲空。否則會有例外。這就是爲什麼網格沒有顯示任何東西！ – Sajeetharan

我建議你編輯你的答案只包括相關的變化。不需要包含與原始代碼相同的代碼。 –

從webservices填充datagrid

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