MVVM模式下ComboBox绑定List，如何获取选中的是哪一项.

[sanlonezh]

MVVM模式下ComboBox绑定List<T>，如何获取选中的是哪一项.
例如 model

   public class SysType:NotificationObject
        {
            private int selectValue;

            public int SelectValue
            {
                get
                { return selectValue; }
                set
                {
                    selectValue = value;
                    this.RaisePropertyChanged("selectValue");
                }
            }
            private string displayName;

            public string DisplayName
            {
                get
                { return displayName; }
                set
                {
                    displayName = value;
                    this.RaisePropertyChanged("displayName");
                }
            }
        }

XML:

<ComboBox Grid.Column="1" Height="23" HorizontalAlignment="Left" Margin="10,143,0,0"
                  ItemsSource="{Binding ListSysType,UpdateSourceTrigger=PropertyChanged}"
DisplayMemberPath="DisplayName" SelectedValue="{Binding SelectValue}"
                  x:Name="CobSysType" VerticalAlignment="Top" Width="120"    >
        </ComboBox>

[幸福小6]

CobSysType.SelectedItem

既是当前选中的元素。

[幸福小6]

不过因为你选择了SelectedValue，所以这里得到的值是你数据结构里SelectValue指定的值，自己去判断，

[sanlonezh]

就是在mvvmModel这个类上我想知道我选取的是哪一行?

[昊子先生]

从change事件里去判断选择的哪一个

[sanlonezh]

如果要用ComboBox的changed事件，哪还用mvvm设计模式干什么！

[sanlonezh]

呵呵找到了。

public class LocationRoad
{
    public int ID { set; get; }
    public string Code { set; get; }
    public string Info { set; get; }
}
//
/// 当ComboBox选中项更改时发生
///
private LocationRoad _selectLocation;
public LocationRoad SelectLocation
{
    get
    {
        return this._selectLocation;
    }
    set
    {
        this._selectLocation = value;
        if (this.PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs("SelectLocation"));
    }
}
 
private ObservableCollection _locationRoad = null;
 
public ObservableCollection LocationSource
{
    get
    {
        if (this._locationRoad == null)
        {
            this._locationRoad = new ObservableCollection() {
                 new LocationRoad() { ID = 1, Code = "NGQ", Info = "南岗区" },
                 new LocationRoad() { ID = 2, Code = "DLQ", Info = "道里区" },
                 new LocationRoad() { ID = 3, Code = "DWQ", Info = "道外区" },
                 new LocationRoad() { ID = 4, Code = "PFQ", Info = "平房区" },
                 new LocationRoad() { ID = 5, Code = "XFQ", Info = "香坊区" },
                 };
 
        }
        return this._locationRoad;
    }
    set
    {
        this._locationRoad = value;
        if (this.PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs("LocationSource"));
    }
}

前台XAML文件绑定方式：

<ComboBox Margin="-16,3,0,5" Grid.Row="1" Grid.Column="2" Grid.ColumnSpan="2" Name="cboxLocationKeyword"
 ItemsSource="{Binding LocationSource,Mode=OneWay}"
 SelectedValuePath="ID"
 DisplayMemberPath="Info"
 SelectedItem="{Binding SelectLocation}" />

如果要进行双向绑定或其他的绑定方式，只要更改上面binging块中的Mode方式就可以了。

[韩依衣佳]

在viewmodel能获取到选中的ID和info吗？

[zhaoufo]

6楼代码 PropertyChanged 只能适用于绑定事件。。 这样写 都不让编译