强大的DataGrid组件[13]_字段过滤(Filter)——Silverlight学习笔记[21]

在DataGrid中使用字段过滤可以用来进行数据的筛选，查找出符合条件的信息。本文将为大家介绍如何对DataGrid执行字段过滤。

需要了解的知识

1）PagedCollectionView

它代表了一个有关分组、排序、筛选和导航的分页数据集合。

2）PagedCollectionView的Filter属性

用来设置PagedCollectionView的过滤器，进行字段信息等过滤。

3）过滤器函数

用作过滤器的主体

实例

详细的说明在代码注释中给出。

MainPage.xaml文件代码：

<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"

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">

<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>

</Grid>

</UserControl>

MainPage.xaml.cs文件代码：

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.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<Employees> GetEmployees()

{

List<Employees> returnedValue = new List<Employees>();

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)

{