WPF绑定并填充组合框 [英] WPF Bind and populate a combobox

问题描述

我是C＃和WPF的新手，我的问题可能对你们这些人来说太容易了：

我编写了一个类成员并设置其参数读取任何本地xml。其中一个参数是Int参数。我想要一个组合框来处理这个参数但是要显示一个字符串。我的方法是创建一个字典，填充组合并从类成员绑定其选定的值：

 使用系统; 
 使用 System.Collections.Generic; 
 使用 System.Linq; 
 使用 System.Text; 
 使用 System.Threading.Tasks; 
 使用 System.Windows; 
 使用 System.Windows.Controls; 
 使用 System.Windows.Data; 
 使用 System.Windows.Documents; 
 使用 System.Windows.Input; 
 使用 System.Windows.Media; 
 使用 System.Windows.Media.Imaging; 
 使用 System.Windows.Navigation; 
 使用 System.Windows.Shapes; 
 使用 System.ComponentModel; 
 使用 System.Xml; 
 使用 System.Xml.Linq; 
 
 命名空间 TempProject 
 {
  class 字典
 {
  public   static 字典< int，string> GetChoise（）
 {
 Dictionary< int，string> MyDict =  new  Dictionary< int，string>（）; 
 MyDict.Add（ 1 ，  choise 1\" ）; 
 MyDict.Add（ 2 ，  choise 2\" ）; 
 MyDict.Add（ 3 ，  choise 3\" ）; 
  return  MyDict; 
} 
} 
 
  public   class  MyModel： INotifyPropertyChanged 
 {
  private   int  m_choise; 
 
  public   event  PropertyChangedEventHandler PropertyChanged; 
  private   void  OnPropertyChanged（ string  propertyName）
 {
  if （PropertyChanged！=  null ）
 {
 PropertyChanged（ this ， new  PropertyChangedEventArgs（propertyName））; 
} 
} 
 
  public   int 选择
 {
  get  { return  m_choise; } 
  set  
 {
  if （ value  <   1  || 值 >   3 ）{ throw   new  OverflowException（）; } 
 m_choise =  value ; OnPropertyChanged（  Choise）; 
} 
} 
} 
 
  public   partial   class  MainWindow：Window 
 {
 MyModel Model1 =  new  MyModel（ ）; 
  public  MainWindow（）
 {
  this  .InitializeComponent（） ; 
 DataContext = Model1; 
} 
 
  private   void  CmdOpenXML（ object  sender，System.Windows.RoutedEventArgs e）
 {
 Microsoft.Win32.OpenFileDialog dlg =  new  Microsoft.Win32.OpenFileDialog（）; 
 dlg.InitialDirectory =  @  C：\; 
 dlg.DefaultExt =  。xml; 
 dlg.Filter =   XML | * .xml; 
 Nullable< bool> result = dlg.ShowDialog（）; 
  if （result ==  true ）
 {
 XDocument xd = XDocument.Load（dlg.FileName）; 
  var  query = 来自 d   xd.Root.Descendants（  PROJECT）
 选择 d; 
  foreach （ var  q  in 查询）
 {Model1.Choise =  Int32  .Parse（q.Element（ < span class =code-string> choise）。Value）; } 
} 
} 
} 
} 

和XAML：

 <  窗口    x：Class   =  TempProject.MainWindow  
   
                   xmlns   =  http ：//schemas.microsoft.com/winfx/2006/xaml/presentation  
   
                   xmlns：x   =   http://schemas.microsoft.com/winfx/2006/xaml  
   
      < span class =code-attribute>             xmlns：local   =  clr-namespace：TempProject  
   
                  标题  =  MainWindow   高度  =  350    宽度  = < span class =code-keyword> 525 >  
 <   Window.Resources  >  
 <   ObjectDataProvider     x：键  =  MyDict  
   
                                                           ObjectType   =  {x：输入local：Dictionaries}  
   
                        < span class =code-attribute>                                   MethodName   =  GetChoise  /  < span class =code-keyword>>  
 <   / Window.Resources  >  
 <   StackPanel    >  
 <  菜单 > ;  
 <   MenuItem    标题  = 文件 >  
 <   MenuItem    标题  = 打开   点击  =  CmdOpenXML    /  >  
 <   / MenuItem  >  
 <   /菜单 >  
 <   TextBox    文字  =  {Binding Choise}    /  >  
 <   ComboBox     ItemsSource   =  {Binding Source = {StaticResource MyDict}}    
   
                                               SelectedValuePath   =  Key     
   
                                               DisplayMemberPath   = 值    
   
                                               SelectedItem   =  {Binding Path = Choise ，Mode = TwoWay}  /  >  
 <   / StackPanel  >  
 <   / Window  >  

但是组合不能正常工作。

你能告诉我我做错了什么吗？一般来说我的方法是否正确？

你能建议我一些关于这个主题的教程吗？

谢谢

解决方案

< blockquote>毕竟很简单。应该在ComboBox中使用SelectedValue而不是SelectedItem

I''m new to C# and WPF and my question may be too easy to some of you:
My prog crates a class member and sets its parameters reading any local xml. One of the parameters is an Int parameter. I want a combobox to handle this parameter but to show a string. My approach is to create a dictionary witch populates the combo and bind its selected value from the class member:

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;
using System.ComponentModel;
using System.Xml;
using System.Xml.Linq;

namespace TempProject
{
    class Dictionaries
    {
        public static Dictionary<int, string> GetChoise()
        {
            Dictionary<int, string> MyDict = new Dictionary<int, string>();
            MyDict.Add(1, "choise 1");
            MyDict.Add(2, "choise 2");
            MyDict.Add(3, "choise 3");
            return MyDict;
        }
    }

    public class MyModel : INotifyPropertyChanged
    {
        private int m_choise;

        public event PropertyChangedEventHandler PropertyChanged;
        private void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public int Choise
        {
            get { return m_choise; }
            set
            {
                if (value < 1 || value > 3) { throw new OverflowException(); }
                m_choise = value; OnPropertyChanged("Choise");
            }
        }
    }

    public partial class MainWindow : Window
    {
        MyModel Model1 = new MyModel();
        public MainWindow()
        {
            this.InitializeComponent();
            DataContext = Model1;
        }

        private void CmdOpenXML(object sender, System.Windows.RoutedEventArgs e)
        {
            Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
            dlg.InitialDirectory = @"C:\";
            dlg.DefaultExt = ".xml";
            dlg.Filter = "XML|*.xml";
            Nullable<bool> result = dlg.ShowDialog();
            if (result == true)
            {
                XDocument xd = XDocument.Load(dlg.FileName);
                var query = from d in xd.Root.Descendants("PROJECT")
                            select d;
                foreach (var q in query)
                { Model1.Choise = Int32.Parse(q.Element("choise").Value); }
            }
        }
    }
}

and the XAML:

<Window x:Class="TempProject.MainWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        xmlns:local="clr-namespace:TempProject"

        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <ObjectDataProvider x:Key="MyDict"

                            ObjectType="{x:Type local:Dictionaries}"

                            MethodName="GetChoise"/>
    </Window.Resources>
    <StackPanel >
            <Menu>
                <MenuItem Header="File">
                    <MenuItem Header="Open" Click="CmdOpenXML" />
                </MenuItem>
            </Menu>
            <TextBox Text="{Binding Choise}" />
            <ComboBox ItemsSource="{Binding Source={StaticResource MyDict}}" 

                      SelectedValuePath="Key" 

                      DisplayMemberPath="Value" 

                      SelectedItem="{Binding Path=Choise,Mode=TwoWay}"/>
    </StackPanel>
</Window>

But the combo does not work correctly.
Can you tell me what am I doing wrong? Is my approach correct in general?
Can you suggest me some tutorials on the subject?
Thank you

解决方案

It was simple after all. Should have used SelectedValue instead of SelectedItem in ComboBox

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