Question

我开始在这里爬墙。我已经填充了一个包含项目列表的组合框，而我正在尝试找出已选择的项目。我还试图将combox框设置为自动选择列表中的第0项。但是这也行不通，我在GroupIndex和SelectedGroup上都遇到了绑定表达式路径错误。但是我无法弄清楚问题是什么。

Combo Box Xaml：

<ComboBox     
Name="GroupComboBox"
SelectedIndex="{Binding Path=GroupIndex}"
SelectedItem="{Binding Path=SelectedGroup}"
DisplayMemberPath="Name"
SelectedValuePath ="Name"
ItemsSource="{Binding Path=Groups}"
Height="38"
HorizontalAlignment="Left"
Margin="159,115,0,0"
VerticalAlignment="Top"
Width="185"
FontSize="24" Text="Select a Group" IsEditable="False" IsReadOnly="False" />

以下是填充组合框的代码。

    void webService_GroupListChanged(string response)
    {
        JavaScriptSerializer serializer = new JavaScriptSerializer();

        IList<JSONGroup> listOfGroups = new List<JSONGroup>();

        listOfGroups = serializer.Deserialize<List<JSONGroup>>(response);

        Application.Current.Dispatcher.BeginInvoke((Action)(() =>
        {
            Groups = new ObservableCollection<Group>();

            foreach(JSONGroup group in listOfGroups)
            {
                Groups.Add(new Group(group.name, group.id));
            }

        }));
    }

    private int groupIndex;
    private int GroupIndex
    {
        get { return this.groupIndex; }
        set
        {
            if (this.groupIndex != value)
            {
                this.groupIndex = value;
                this.OnPropertyChanged("GroupIndex");
            }
        }
    }


    private Group selectedGroup;
    private Group SelectedGroup
    {
        get { return this.selectedGroup; }
        set
        {
            if (this.selectedGroup != value)
            {
                this.selectedGroup = value;
                this.OnPropertyChanged("SelectedGroup");
            }
        }
    }


    private ObservableCollection<Group> groups;
    public ObservableCollection<Group> Groups
    {
        get { return this.groups; }
        set
        {
            if (this.groups != value)
            {
                this.groups = value;
                this.OnPropertyChanged("Groups");
            }
        }
    }

Answer 1

要用于绑定，您的GroupIndex和SelectedGroup属性必须为public。
请勿同时设置SelectedItem和SelectedIndex。
如果您希望设置SelectedItem，则必须在SelectedGroup中包含该确切项目Groups。

无法获取组合框的SelectedItem或SelectedIndex

1 个答案: