WPF通知中的可观察集合 [英] Observable Collection in WPF Notification

问题描述

Hi Experts
我将组合框"与可观察的集合"绑定，但是添加项目后，它不是自动刷新".

我有C#代码.是

Hi Experts
I Bind Combobox with Observable Collection but After add Item It is not Refresh Auto.

I Have C# Code. is

class ClsEmp : INotifyPropertyChanged
   {
       int _EmpCode;
       public int EmpCode
       {
           get {return _EmpCode ;}

           set { _EmpCode = value; NotifyPropertyChanged("EmpCode"); }

       }
       string _EmpName;
       public string EmpName
       {
           get { return _EmpName; }

           set { _EmpName = value; NotifyPropertyChanged("EmpName"); }
       }
       System.Collections.ObjectModel.ObservableCollection<ClsEmp> dataItem = new System.Collections.ObjectModel.ObservableCollection<ClsEmp>();


       public ObservableCollection<ClsEmp> DropDownValues
       {
           get
           {
               return dataItem;

           }

           set
           {
               dataItem = value;
               NotifyPropertyChanged("DropDownValues");

           }

       }

       public ClsEmp(int EmpCode,string EmpName)
       {
           EmpCode = this.EmpCode;
           EmpName = this.EmpName;


       }
       public ClsEmp()
       {
       }
       public event PropertyChangedEventHandler PropertyChanged;

       private void NotifyPropertyChanged(string strPropertyName)
       {

           PropertyChangedEventHandler handler = PropertyChanged;

           if (handler != null)
           {
               handler(this, new PropertyChangedEventArgs(strPropertyName));
           }
       }

   }

和与Combobox绑定的代码；

and Code For Bind With Combobox;

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            LoadCombo();
        }
        ClsEmp cls =  new ClsEmp();
        private void btnAdd_Click(object sender, RoutedEventArgs e)
        {
            cls.EmpCode = 6;
            cls.EmpName = txt.Text;
            cls.DropDownValues.Add(cls);

        }
        private void LoadCombo()
        {
            cls.DropDownValues.Add(new ClsEmp { EmpCode = 1, EmpName = "A" });
            cls.DropDownValues.Add(new ClsEmp { EmpCode = 2, EmpName = "B" });
            cls.DropDownValues.Add(new ClsEmp { EmpCode = 3, EmpName = "C" });
            cls.DropDownValues.Add(new ClsEmp { EmpCode = 4, EmpName = "D" });
            cls.DropDownValues.Add(new ClsEmp { EmpCode = 5, EmpName = "E" });
            cmb.ItemsSource = cls.DropDownValues.ToList();
        }
    }

.Xmal代码为

.Xmal Code is

<ComboBox x:Name="cmb" Grid.Row="1" Grid.Column="1"

          DisplayMemberPath="EmpName" ItemsSource="{Binding Source={x:Static Application.Current}, Path=DropDownValues , Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></ComboBox>
<TextBox x:Name="txt" Grid.Row="1" Grid.Column="2" Text="{Binding EmpName}"></TextBox>
<Button x:Name="btnAdd" Grid.Row="1" Grid.Column="3" Content="Add" Click="btnAdd_Click"></Button>

谢谢你
Dinesh Sharma

Thank u
Dinesh Sharma

推荐答案

此行；

This line;

cmb.ItemsSource = cls.DropDownValues.ToList();

没有意义，您正在获取副本，而不是您的DropDownValues 列表引用.不要使用这样的ToList方法，将其更改为:

makes no sense, you''re grabbing a copy, not a reference of your DropDownValues list. Don'' use the ToList method like that, change it to:

cmb.ItemsSource = cls.DropDownValues;

它应该可以工作(我实际上没有尝试过).


希望这会有所帮助，
Fredrik Bornander

and it should work (I haven''t actually tried it).


Hope this helps,
Fredrik Bornander

我完全同意Fredrick.
cmb.ItemsSource = cls.DropDownValues.ToList();没有意义，应将其删除.

您正在xaml中设置ItemsSource ...因此就可以了.

I agree with Fredrick totally.
cmb.ItemsSource = cls.DropDownValues.ToList(); is nt making sense and should be removed.

You are setting the ItemsSource in the xaml...so just that should be fine.

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