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初步探讨WPF的ListView控件(涉及模板、查找子控件)

     本文结合模板的应用初步介绍ListView的应用

一、Xaml中如何建立数据资源

      大部分数据都会来自于后台代码,如何Xaml同样的建立数据源呢?比如建立一个学生List:

      首先引入命名空间: xmlns:c="clr-namespace:System.Collections;assembly=mscorlib"

      然后代码如下:     

  <c:ArrayList x:Key="stuList">
            <local:Student Id="1" Name="小明" Grade="研一" Professional="计算机技术" HasJob="true"></local:Student>
            <local:Student Id="2" Name="小李" Grade="大一" Professional="网络工程" HasJob="true"></local:Student>
            <local:Student Id="3" Name="小张" Grade="研一" Professional="软件工程" HasJob="False"></local:Student>
            <local:Student Id="4" Name="小王" Grade="研一" Professional="自动化控制" HasJob="true"></local:Student>
            <local:Student Id="5" Name="大王" Grade="研一" Professional="软件设计" HasJob="False"></local:Student>
        </c:ArrayList>

二、定义数据展示模板
      展示数据使用的是ListView的View属性,MSDN解释:Gets or sets an object that defines how the data is styled and organized in a ListView control. 说明是可以在里面放一些数据样式和一些控件模板的。其实这个Control暂时只能是GridView。每一个Student就是一列数据,我们要把学生显示到列上,所以就用到了GridView的GridViewColumn属性。关于GridView不在细说,请查阅MSDN。

      最终数据是展示在GridViewColumn上面的,那么我们就开始设计我们GridViewColumn的数据模板,代码如下:

     

        <DataTemplate x:Key="NameDt">            <TextBox x:Name="textboxName" Text="{Binding Name}" GotFocus="textboxName_GotFocus"></TextBox>        </DataTemplate>        <DataTemplate x:Key="GradeDt">            <TextBox x:Name="textboxGrade" Text="{Binding Grade}"></TextBox>                    </DataTemplate>        <DataTemplate x:Key="ProfessionalDt">            <TextBox x:Name="textboxProfessional" Text="{Binding Professional}"></TextBox>        </DataTemplate>        <DataTemplate x:Key="HasJobDt">            <CheckBox x:Name="CheckBocHasJob" IsChecked="{Binding HasJob}"></CheckBox>                    </DataTemplate>

      我们为每列数据定义了数据展示模板,当然你也可以自己定义别的,我仅仅是示例下!
三、使用ListView展示数据

      有了以上的准备,下面就是通过ListView把数据和数据模板,通过绑定等联接起来了,需要注意的是,我们第二步定义的模板应用到的是CellTemplate上面,其实就是单元格的数据模板。

      代码如下:

     

  <ListView x:Name="ListViewStudent" ItemsSource="{StaticResource stuList}">            <ListView.View>                <GridView>                    <GridViewColumn Header="ID" DisplayMemberBinding="{Binding Id}"></GridViewColumn>                    <GridViewColumn Header="姓名" CellTemplate="{StaticResource NameDt}"></GridViewColumn>                    <GridViewColumn Header="年级" CellTemplate="{StaticResource GradeDt}"></GridViewColumn>                    <GridViewColumn Header="专业" CellTemplate="{StaticResource ProfessionalDt}"></GridViewColumn>                    <GridViewColumn Header="已工作" CellTemplate="{StaticResource HasJobDt}"></GridViewColumn>                </GridView>            </ListView.View>        </ListView>

     这样与运行程序,成功实现了绑定,并通过自己自定义的模板显示了数据,而且数据显示格式是自定义的,当然你可以不用模板,使用默认的模板,这样是不能改动数据的。默认的我就不介绍了。

四、ListView之数据操作

      数据展示完了,那么数据操作呢?

      比如我们有这么一个需求:当点击CheckBox时候,需要获取学生的信息,然后进行相关操作等。

      我们在CheckBox的Checked事件下面写如下代码:

      

private void CheckBocHasJob_Checked(object sender, RoutedEventArgs e)        {            CheckBox tb = e.OriginalSource as CheckBox;            ContentPresenter cp = tb.TemplatedParent as ContentPresenter;            Student stu = cp.Content as Student;            MessageBox.Show(stu.Name + stu.Grade + stu.Professional);                                      }

      这段代码不难理解,首先通过 e.OriginalSource获取是那个控件触发的事件,通过控件的TemplatedParent属性,查找到上层的数据展示模板(其实是ListView视觉树里面的数据呈现模板)。这样通过Content属性即可获得Student的相关信息了。

五、Listview之控件查找

      比如有这么一个需求:我想知道我点击选中checkbox的时候,这个CheckBox的控件名字是什么?

      首先分析一下,CheckBox是模板里面的,不在逻辑树上,肯定要是用VaisualTreeHelper这个类,实现这个功能之前需要借助一个函数,此函数功能是获取控件逻辑树或视觉树上的指定类型控件。如下:

    

private ChildType FindVisualChild<ChildType>(DependencyObject obj) where ChildType : DependencyObject        {            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)            {                DependencyObject child = VisualTreeHelper.GetChild(obj,i);                if (child!=null&& child is ChildType)                {                    return child as ChildType;                }                else                {                    ChildType childOfChildren = FindVisualChild<ChildType>(child);                    if (childOfChildren!=null)                    {                        return childOfChildren;                    }                }            }            return null;                    }

       有了以上这个函数,功能就很好实现了,ListviewItem作为参数传入,查找CheckBox类型的控件即可:修改Checked事件代码如下:

       private void CheckBocHasJob_Checked(object sender, RoutedEventArgs e)        {            //访问业务逻辑数据            CheckBox tb = e.OriginalSource as CheckBox;            ContentPresenter cp = tb.TemplatedParent as ContentPresenter;            Student stu = cp.Content as Student;            MessageBox.Show(stu.Name + stu.Grade + stu.Professional);            // this.ListViewStudent.SelectedItem = stu;            //访问界面元素            ListViewItem lvi = this.ListViewStudent.ItemContainerGenerator.ContainerFromItem(stu) as ListViewItem;            CheckBox cb = FindVisualChild<CheckBox>(lvi);            MessageBox.Show(cb.Height + cb.Name + cb.Width);                   }

OK,这样你就可以成功获取到你想要的任何东西了~~~

全部代码:

Xaml:

<Window x:Class="ContentDataTemplate.MainWindow"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        xmlns:c="clr-namespace:System.Collections;assembly=mscorlib"        xmlns:local="clr-namespace:ContentDataTemplate"        Title="MainWindow" Height="350" Width="525">    <Window.Resources>        <c:ArrayList x:Key="stuList">            <local:Student Id="1" Name="小明" Grade="研一" Professional="计算机技术" HasJob="true"></local:Student>            <local:Student Id="2" Name="小李" Grade="大一" Professional="网络工程" HasJob="true"></local:Student>            <local:Student Id="3" Name="小张" Grade="研一" Professional="软件工程" HasJob="False"></local:Student>            <local:Student Id="4" Name="小王" Grade="研一" Professional="自动化控制" HasJob="true"></local:Student>            <local:Student Id="5" Name="大王" Grade="研一" Professional="软件设计" HasJob="False"></local:Student>        </c:ArrayList>        <DataTemplate x:Key="NameDt">            <TextBox x:Name="textboxName" Text="{Binding Name}" GotFocus="textboxName_GotFocus"></TextBox>        </DataTemplate>        <DataTemplate x:Key="GradeDt">            <TextBox x:Name="textboxGrade" Text="{Binding Grade}"></TextBox>                    </DataTemplate>        <DataTemplate x:Key="ProfessionalDt">            <TextBox x:Name="textboxProfessional" Text="{Binding Professional}"></TextBox>        </DataTemplate>        <DataTemplate x:Key="HasJobDt">            <CheckBox x:Name="CheckBocHasJob" IsChecked="{Binding HasJob}" Checked="CheckBocHasJob_Checked"></CheckBox>                    </DataTemplate>    </Window.Resources>    <Grid Margin="5">        <ListView x:Name="ListViewStudent" ItemsSource="{StaticResource stuList}">            <ListView.View>                <GridView>                    <GridViewColumn Header="ID" DisplayMemberBinding="{Binding Id}"></GridViewColumn>                    <GridViewColumn Header="姓名" CellTemplate="{StaticResource NameDt}"></GridViewColumn>                    <GridViewColumn Header="年级" CellTemplate="{StaticResource GradeDt}"></GridViewColumn>                    <GridViewColumn Header="专业" CellTemplate="{StaticResource ProfessionalDt}"></GridViewColumn>                    <GridViewColumn Header="已工作" CellTemplate="{StaticResource HasJobDt}"></GridViewColumn>                </GridView>            </ListView.View>        </ListView>    </Grid></Window>
View Code

C# CODE:

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;namespace ContentDataTemplate{    class Student    {        public int Id { get; set; }        public string Name { get; set; }        public string Grade { get; set; }        public string  Professional { get; set; }        public bool HasJob { get; set; }    }    /// <summary>    /// MainWindow.xaml 的交互逻辑    /// </summary>    public partial class MainWindow : Window    {        public MainWindow()        {            InitializeComponent();        }        private void textboxName_GotFocus(object sender, RoutedEventArgs e)        {            //访问业务逻辑数据            TextBox tb = e.OriginalSource as TextBox;            ContentPresenter cp = tb.TemplatedParent as ContentPresenter;            Student stu = cp.Content as Student;            MessageBox.Show(stu.Name + stu.Grade + stu.Professional);           // this.ListViewStudent.SelectedItem = stu;            //访问界面元素            ListViewItem lvi = this.ListViewStudent.ItemContainerGenerator.ContainerFromItem(stu) as ListViewItem;//获取ListViewItem            CheckBox cb = FindVisualChild<CheckBox>(lvi);            MessageBox.Show(cb.Name);                   }        /// <summary>        /// 寻找某个控件下的子控件        /// </summary>        /// <typeparam name="ChildType"></typeparam>        /// <param name="obj"></param>        /// <returns></returns>        private ChildType FindVisualChild<ChildType>(DependencyObject obj) where ChildType : DependencyObject        {            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)            {                DependencyObject child = VisualTreeHelper.GetChild(obj,i);                if (child!=null&& child is ChildType)                {                    return child as ChildType;                }                else                {                    ChildType childOfChildren = FindVisualChild<ChildType>(child);                    if (childOfChildren!=null)                    {                        return childOfChildren;                    }                }            }            return null;                    }        private void CheckBocHasJob_Checked(object sender, RoutedEventArgs e)        {            //访问业务逻辑数据            CheckBox tb = e.OriginalSource as CheckBox;            ContentPresenter cp = tb.TemplatedParent as ContentPresenter;            Student stu = cp.Content as Student;            MessageBox.Show(stu.Name + stu.Grade + stu.Professional);            // this.ListViewStudent.SelectedItem = stu;            //访问界面元素            ListViewItem lvi = this.ListViewStudent.ItemContainerGenerator.ContainerFromItem(stu) as ListViewItem;            CheckBox cb = FindVisualChild<CheckBox>(lvi);            MessageBox.Show(cb.Height + cb.Name + cb.Width);                   }    }}
View Code

 后面我会继续深入介绍ListView的使用,包括样式、分组、排序等,敬请期待。

 

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作者:GavinDream(GavinJune主页 博客园) 出处:http://www.cnblogs.com/fuchongjundream/ 任何转载必须保留完整文章,在显要地方显示署名以及原文链接。如您有任何疑问或者授权方面的协商,请发邮件给我 或者 留言。