Question

我正在使用WPF，MVVM和DevExpress GridControl。我的MainWindow.xaml中有两个面板。 Panle1有Grid，Panel2有Textbox。我希望如果我从Panel1中的Grid中选择一个项目，它的名称应显示在Panle2文本框中。我写了代码，但它没有用。你能帮帮我解决这个问题吗？

*在NameModel中从模型文件夹我写道： *

private NameModelClass _selectedCustomer;
public NameModelClass SelectedCustomer
{
    get { return _selectedCustomer; }
    set
    {
        if (_selectedCustomer != value)
        {
            _selectedCustomer = value;
            LastName = value.LastName;
            OnPropertyChanged("SelectedCustomer");
        }
     }

    public List<Namess> ListPerson { get; set; }

    void CreateList()
    {
        ListPerson = new List<Namess>();
        for (int i = 0; i < 10; i++)
        {
            ListPerson.Add(new Namess(i));
        }
    }

    public class Namess
    {
        public Namess(int i)
        {
            FirstName = "FirstName" + i;
            LastName = "LastName" + i;
            Age = i * 10;
        }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public int Age { get; set; }
    }
}

在MianWindow.xaml中，我写道：

<dxdo:LayoutPanel Caption="Grid" Caption="Panel1" x:Name="abc1">
    <Grid>
        <dxg:GridControl x:Name="grid" Height="233" ItemsSource="{Binding ListPerson}" AutoGenerateColumns="AddNew" HorizontalAlignment="Left" VerticalAlignment="Top"   SelectedItem="{Binding SelectedNames}">
            <dxg:GridControl.View>
                <dxg:TableView ShowTotalSummary="True"/>
            </dxg:GridControl.View>
        </dxg:GridControl>
    </Grid>
</dxdo:LayoutPanel>

<dxdo:LayoutPanel Caption="Panel2" x:Name="abc1">
    <TextBox Width="166" Background="White" Height="33"  HorizontalAlignment="Right"  VerticalAlignment="Bottom"  Text="{Binding Path=LastName}"/>
</dxdo:LayoutPanel>

我是MVVM和c＃的新手。我的询问不清楚，请问我。谢谢。

Answer 1

我是这样做的：

private Namess _selectedCustomer;
public Namess SelectedCustomer
{
    get { return _selectedCustomer; }
    set
    {
        if (_selectedCustomer != value)
        {
            _selectedCustomer = value;
            OnPropertyChanged("SelectedCustomer");
        }
     }

    public List<Namess> ListPerson { get; set; }

    void CreateList()
    {
        ListPerson = new List<Namess>();
        for (int i = 0; i < 10; i++)
        {
            ListPerson.Add(new Namess(i));
        }
    }

    public class Namess : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
                handler(this, new PropertyChangedEventArgs(propertyName));
        }

        public Namess(int i)
        {
            FirstName = "FirstName" + i;
            LastName = "LastName" + i;
            Age = i * 10;
        }
        public string FirstName { get; set; }
        private string _lastName;
        public string LastName 
        { 
            get
            {
                return _lastName;
            }
            set
            {
                if(value==_lastName)
                    return;
                _lastName=value;
                OnPropertyChanged("LastName");
            }
        }
        public int Age { get; set; }
    }
}

并在您看来：

<dxdo:LayoutPanel Caption="Grid" Caption="Panel1" x:Name="abc1">
    <Grid>
        <dxg:GridControl x:Name="grid" Height="233" ItemsSource="{Binding ListPerson}" AutoGenerateColumns="AddNew" HorizontalAlignment="Left" VerticalAlignment="Top" SelectedItem="{Binding SelectedNames,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}">
            <dxg:GridControl.View>
                <dxg:TableView ShowTotalSummary="True"/>
            </dxg:GridControl.View>
        </dxg:GridControl>
    </Grid>
</dxdo:LayoutPanel>

<dxdo:LayoutPanel Caption="Panel2" x:Name="abc1">
    <TextBox Width="166" Background="White" Height="33"  HorizontalAlignment="Right" VerticalAlignment="Bottom"  Text="{Binding Path=SelectedCustomer.LastName,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}"/>
</dxdo:LayoutPanel>

Bsically我将SelectedCustomer的类型更改为其中一个项目集合。在视图中，您可以将TextBox的绑定直接设置为SelectedCustomer的属性。

Answer 2

你试过了吗？

SelectedItem =“{Binding SelectedNames，Mode = TwoWay}”

在查看更多内容后，您的主要Namess类可以实现INotifyPropertyChanged

当 ahem 更改时，每个属性都会引发属性更改事件。

同样使用可观察的集合，因此当您添加和删除项目时，它也会引发更改。

这样，通知更改系统会收到属性更改通知，以通过绑定相应地更改视图。

Answer 3

看起来您忘了为“LastName”字符串引发INPC（INotifyPropertyChanged）事件。

所以试试这个（在下面的setter中更改）：

public NameModelClass SelectedCustomer
    {
    get { return _selectedCustomer; }
    set
        {
        if (_selectedCustomer != value)
            {
            _selectedCustomer = value;
            LastName = value.LastName;
            OnPropertyChanged("SelectedCustomer");
            OnPropertyChanged("LastName");   //<-- new 
            }
        }
    }

您必须发送INPC，以便绑定知道更新为新值。显示的绑定不会“抓取”您举起该事件的LastName unles的新值。

如何绑定MVVM中的选定项目

3 个答案: