Question

当我从另一个xaml（菜单）中选择项目时，我想要做的是基本上在一个xaml（Basket）中填充带有项目名称的文本框。我的代码如下：

Menu.xaml

在这里，当我点击一个按钮时，我希望它自动出现在Basket.xaml的文本框中。

    public class PassedData
    {
        public string Name { get; set; }
        public int Value { get; set; }
    }
    private void Vanbtn_Click(object sender, RoutedEventArgs e)
    {


        Frame.Navigate(typeof(Basket), new PassedData { Name = "Cheese" });
    }

    private void LCbtn_Click(object sender, RoutedEventArgs e)
    {
        Frame.Navigate(typeof(Basket), new PassedData { Name = "Crisp" });
    }

Basket.xaml

       protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        Menu.PassedData data = e.Parameter as Menu.PassedData;
    /**    ItemChosentxt.Text = data.Name;
        ItemChosentxt2.Text = data.Name;
        ItemChosentxt3.Text = data.Name;
        ItemChosentxt4.Text = data.Name;**/


    }

注释掉的部分会添加所选项目的名称。而不只是添加到一个文本框添加到所有文本框。即如果我在Menu.xaml中选择了vanilla btn，则名称将出现在所有4个文本框中，而不是仅显示在一个文本框中。所以我决定在每个文本框中实现代码：

private void ItemChosentxt_TextChanged(object sender, TextChangedEventArgs e)
    {
        Menu.PassedData data = e.Parameter as Menu.PassedData;
        ItemChosentxt.Text = data.Name;
    }

    private void SecItem_TextChanged(object sender, TextChangedEventArgs e)
    {
        Menu.PassedData data = e.Parameter as Menu.PassedData;
        SecItem.Text = data.Name;
    }

这会在e.Parameter下面显示错误代码 -

Severity    Code    Description Project File    Line    Suppression State
    Error   CS0103  The name 'data' does not exist in the current context

和

    Severity    Code    Description Project File    Line    Suppression State
Error   CS1061  'TextChangedEventArgs' does not contain a definition for 'Parameter' and no extension method 'Parameter' accepting a first argument of type 'TextChangedEventArgs' could be found (are you missing a using directive or an assembly reference?)

我正在开发一个购物应用程序，例如如果用户从菜单中选择“Vanilla”和“Cake”，如何将名称显示在Basket文本框中？我是应用程序开发的新手，并为长期问题道歉。

Answer 1

问题是你没有用PassedData提供TextChangedEventArgs e。

编译器专门对你大喊大叫

用于说e.Paramenter（TextChangedEventArgs没有＆＃34;参数＆＃34;成员）
用于使用＆＃34;数据＆＃34;，由于1而未定义。

但是，我建议采用完全不同的方法。只需使用listview（和数据绑定）。
示例：

<强> Basket.xaml

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <ListView ItemsSource="{Binding PassedData}" HorizontalAlignment="Center" VerticalAlignment="Center">
        <ListView.ItemTemplate>
            <DataTemplate>
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="auto"/>
                        <ColumnDefinition Width="auto"/>
                    </Grid.ColumnDefinitions>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="auto"/>
                    </Grid.RowDefinitions>
                    <TextBox Grid.Column="0" Text="{Binding Name}" />
                    <TextBox Grid.Column="1" Text="{Binding Value}" />
                </Grid>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>
</Grid>

<强> Basket.xaml.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

    // namespace ...

public sealed partial class Basket : Page
{
    private static ObservableCollection<Menu.PassedData> passedData = new ObservableCollection<Menu.PassedData>();
    public ObservableCollection<Menu.PassedData> PassedData
    {
        get { return passedData; }
        set { passedData = value; }
    }


    /*Events*/

    public event PropertyChangedEventHandler PropertyChanged;

    /*Methods*/

    /// Fires PropertyChangedEventHandler, for bindables
    protected void OnPropertyChanged(string name)
    {
        var ev = PropertyChanged;
        if (ev != null)
        {
            ev(this, new PropertyChangedEventArgs(name));
        }
    }

    public Basket()
    {
        this.InitializeComponent();
        this.DataContext = this;
    }

    protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        Menu.PassedData data = e.Parameter as Menu.PassedData;
        /**    ItemChosentxt.Text = data.Name;
            ItemChosentxt2.Text = data.Name;
            ItemChosentxt3.Text = data.Name;
            ItemChosentxt4.Text = data.Name;**/
        if (data != null)
        {
            PassedData.Add(data);
        }

    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        Frame.Navigate(typeof(Menu));
    }
}

}

如何填充文本框 - Windows Phone 8.1

1 个答案: