Question

我需要保存在运行时由用户更改的组合框值，并在下次加载页面时将其显示为组合框默认值。我问这是我的UWP申请。我在Settings.xaml中定义了一个组合框，如下所示：

<ComboBox Name="CLengthCombo" SelectionChanged="ComboBox_SelectionChanged">
             <ComboBoxItem Content="24"/>
             <ComboBoxItem Content="25"/>
             <ComboBoxItem Content="26" IsSelected="True"/>
             <ComboBoxItem Content="27"/>
</ComboBox>

在我的Settings.xaml.cs中，我定义了一个名为＆＃34; localSettings_CycleLength＆＃34;的全局变量。为了保存更改的组合框值，使其保持在应用程序启动之间：

Windows.Storage.ApplicationDataContainer localSettings_CycleLength = Windows.Storage.ApplicationData.Current.LocalSettings;

然后我在Settings.xaml.cs中有以下代码：

public Settings()
     {
         this.InitializeComponent();
         if (localSettings_CycleLength.Values["CycleLength"] != null)
         {
             this.CLengthCombo.SelectedItem = localSettings_CycleLength.Values["CycleLength"];
         }
     }


 private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
     {
         var comboBoxItem = e.AddedItems[0] as ComboBoxItem;
         if (comboBoxItem == null) return;
         comboBoxItem.IsSelected = true;
         var content = comboBoxItem.Content as string;
         if (content != null)
         {
             localSettings_CycleLength.Values["CycleLength"] = content;
         }
    }

现在，上面的代码没有做我需要的，我也不知道为什么。你能帮帮我吗？先谢谢你！

Answer 1

您正在存储所选ComboBoxItem的内容。因此，您无法将内容分配给SelectedItem

你应该这样做

if (localSettings_CycleLength.Values.ContainsKey("CycleLength"))
            {
                var savedItem = localSettings_CycleLength.Values["CycleLength"]; ;
                foreach(var item in CLengthCombo.Items)
                {
                    if((item as ComboBoxItem).Content.Equals(savedItem ))
                    {
                        this.CLengthCombo.SelectedItem = item;
                    }
                }
            }

你的xaml中有<ComboBoxItem Content="26" IsSelected="True"/>。所以每次加载页面时都会选择26覆盖之前选择的项目

如何保存更改的ComboBox值，并在下次加载页面时将其显示为ComboBox默认值

1 个答案: