<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"
    mc:Ignorable="d" xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data" x:Class="SilverlightClient.MainPage"
    d:DesignWidth="320" d:DesignHeight="240">
    <Grid x:Name="LayoutRoot" Background="White" Width="320" Height="240">
        <TextBlock Height="24" HorizontalAlignment="Left" Margin="8,8,0,0" VerticalAlignment="Top" Width="67" Text="过滤字段：" TextWrapping="Wrap" FontSize="13.333"/>
        <ComboBox x:Name="cbColumns" FontSize="14" Height="24" Margin="75,8,135,0" VerticalAlignment="Top"/>
        <TextBlock Height="24" HorizontalAlignment="Right" Margin="0,8,104,0" VerticalAlignment="Top" Width="27" FontSize="13.333" Text="值：" TextWrapping="Wrap"/>
        <TextBox x:Name="tbValue" Height="24" FontSize="14" HorizontalAlignment="Right" Margin="0,8,8,0" VerticalAlignment="Top" Width="92" TextWrapping="Wrap"/>
        <data:DataGrid x:Name="dgEmployee" AutoGenerateColumns="False" Margin="7,36,7,45" FontSize="14">
            <data:DataGrid.Columns>
                <data:DataGridTextColumn Header="工号" Binding="{Binding EmployeeID}"/>
                <data:DataGridTextColumn Header="姓名" Binding="{Binding EmployeeName}"/>
                <data:DataGridTextColumn Header="年龄" Binding="{Binding EmployeeAge}"/>
                <data:DataGridTextColumn Header="部门" Binding="{Binding DepartmentName}"/>
                <data:DataGridTextColumn Header="级别" Binding="{Binding Level}"/>
            </data:DataGrid.Columns>
        </data:DataGrid>
            <Button x:Name="btnFilter" Height="30" HorizontalAlignment="Left" Margin="7,0,0,8" VerticalAlignment="Bottom" Width="68" Content="过滤" FontSize="13.333"/>
        <Button x:Name="btnRestore" Height="30" HorizontalAlignment="Left" Margin="88,0,0,8" VerticalAlignment="Bottom" Width="68" Content="重置" FontSize="13.333"/>
    </Grid>
</UserControl>

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.Windows.Data;

namespace SilverlightClient
...{
    public class Employees
    ...{
        public int EmployeeID ...{ get; set; }
        public string EmployeeName ...{ get; set; }
        public int EmployeeAge ...{ get; set; }
        public string DepartmentName ...{ get; set; }
        public string Level ...{ get; set; }
    }

    public partial class MainPage : UserControl
    ...{
        PagedCollectionView pcv;

        public MainPage()
        ...{
            InitializeComponent();
            this.Loaded += new RoutedEventHandler(MainPage_Loaded);
            this.btnFilter.Click += new RoutedEventHandler(btnFilter_Click);
            this.btnRestore.Click += new RoutedEventHandler(btnRestore_Click);
        }

        public List<string> GetColumns()
        ...{
            List<string> c = new List<string>();
            c.Add("员工号");
            c.Add("姓名");
            c.Add("年龄");
            c.Add("部门");
            c.Add("级别");
            return c;
        }

        public List GetEmployees()
        ...{
            List returnedValue = new List();
            returnedValue.Add(new Employees() ...{ EmployeeID = 1, EmployeeName = "张三", EmployeeAge = 23, DepartmentName = "财务部", Level = "初级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 2, EmployeeName = "李四", EmployeeAge = 24, DepartmentName = "财务部", Level = "中级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 3, EmployeeName = "王五", EmployeeAge = 25, DepartmentName = "管理部", Level = "中级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 4, EmployeeName = "赵六", EmployeeAge = 26, DepartmentName = "管理部", Level = "初级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 5, EmployeeName = "钱七", EmployeeAge = 27, DepartmentName = "工程部", Level = "中级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 6, EmployeeName = "孙八", EmployeeAge = 28, DepartmentName = "工程部", Level = "初级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 7, EmployeeName = "小赵", EmployeeAge = 26, DepartmentName = "财务部", Level = "中级" });
            returnedValue.Add(new Employees() ...{ EmployeeID = 8, EmployeeName = "小钱", EmployeeAge = 28, DepartmentName = "财务部", Level = "高级" });
            return returnedValue;
        }

        void MainPage_Loaded(object sender, RoutedEventArgs e)
        ...{
            GetRestore();
        }

        void btnRestore_Click(object sender, RoutedEventArgs e)
        ...{
            GetRestore();
        }

        void btnFilter_Click(object sender, RoutedEventArgs e)
        ...{
            if (cbColumns.SelectedIndex != -1 && tbValue.Text != "")
            ...{
                switch (cbColumns.SelectedIndex)
                ...{
                    case 0:
                    pcv.Filter = new Predicate<object>(FilterEmployeeID);
                    break;
                    case 1:
                    pcv.Filter = new Predicate<object>(FilterEmployeeName);
                    break;
                    case 2:
                    pcv.Filter = new Predicate<object>(FilterEmployeeAge);
                    break;
                    case 3:
                    pcv.Filter = new Predicate<object>(FilterDepartmentName);
                    break;
                    case 4:
                    pcv.Filter = new Predicate<object>(FilterLevel);
                    break;
                }
            }
        }
      
        //过滤器函数
        public bool FilterEmployeeID(object t)
        ...{
            Employees em = t as Employees;
            return (em.EmployeeID == Convert.ToInt32(tbValue.Text));
        }

        public bool FilterEmployeeName(object t)
        ...{
            Employees em = t as Employees;
            return (em.EmployeeName == Convert.ToString(tbValue.Text));
        }

        public bool FilterEmployeeAge(object t)
        ...{
            Employees em = t as Employees;
            return (em.EmployeeAge >= Convert.ToInt32(tbValue.Text));//这里用的是大于等于条件
        }

        public bool FilterDepartmentName(object t)
        ...{
            Employees em = t as Employees;
            return (em.DepartmentName == Convert.ToString(tbValue.Text));
        }

        public bool FilterLevel(object t)
        ...{
            Employees em = t as Employees;
            return (em.Level == Convert.ToString(tbValue.Text));
        }

        //重置信息
        public void GetRestore()
        ...{
            pcv = new PagedCollectionView(GetEmployees());
            dgEmployee.ItemsSource = pcv;
            cbColumns.ItemsSource = GetColumns();
            cbColumns.SelectedIndex = 0;
            tbValue.Text = String.Empty;
        }
    }
}