c# – 如果itemsource中不存在值,则Combobox指定null

现在,当您加载编辑屏幕时,它会将列表绑定到组合框并显示您设置的变量.

您必须编写一些代码来检查所选项是否出现在列表中,如果不是,则可以将值设置为零.

例：

XAML代码：

<ComboBox ItemsSource="{Binding Path=DeviceNameList}" SelectedItem="{Binding Path=SelectedDeviceName}" />

用于设置selectedItem的代码：

/// <summary>
    /// Gets or sets SelectedDeviceName.
    /// </summary>
    public ObservableCollection<string> DeviceNameList
    {
         get
        {
           return mDeviceNameList;
        }

        set
        {
            mDeviceNameList = value;
        }
    }

    /// <summary>
    /// Gets or sets SelectedDeviceName.
    /// </summary>
    public string SelectedDeviceName
    {
        get
        {
            return mSelectedDeviceName;
        }

        set
        {
            mSelectedDeviceName = value;
            NotifyPropertyChanged("SelectedDeviceName");
        }
    }

    /// <summary>
    /// Event PropertyChanged
    /// </summary>
    public event PropertyChangedEventHandler PropertyChanged;


        /// <summary>
    /// Function NotifyPropertyChanged
    /// </summary>
    /// <param name="property">
    /// The property.
    /// </param>
    private void NotifyPropertyChanged(string property)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this,new PropertyChangedEventArgs(property));
        }
    }