Question

我正在尝试编写一个Silverlight应用程序（使用Silverlight 5.1，.Net 4.5），我希望有3个数据网格。

第一个数据网格显示症状列表，第二个数据网格应列出datagrid1中所选症状的子症状，第三个数据网格应显示一种能够治愈子症状的“盐”。 datagrids应通过WCF Webservices接收数据。第一个datagrid从表症状中获取所有数据，第二个datagrids仅从webservice获取datagrid1中所选症状的子样本，而“salt”数据网格只接收与Web服务中所选症状和子症状一起使用的盐。

一旦我选择了症状，就会出现这些次级症状，一旦我选择了子症状，就会出现相应的盐。一切都很好。

我遇到的问题：当我选择一个子症状而不是再次选择Datagrid1中的一个症状时，所有数据网格都会消失。

以下是代码：

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());
        }

    }
}

这里是.xaml代码

<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>

这里是网络服务代码：

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;
                }
            }
        }
    }
}

最后是帮助班

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; }
    }
}

Answer 1

这是完整的源代码，试试这个

Code 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());

        }
    }

从Web服务填充数据网格

1 个答案: