Question

我有一个wpf应用程序，提示用户输入一些数字输入，用于设置从主窗口设置过时时间的秒数。该值默认为120，如果用户希望更改它，他会点击按钮，窗口的新实例会出现并提示用户更改它，我有数字验证部分工作，但是如果用户单击取消按钮时，当前值将替换为空白（＆＃34;＆＃34;），空格，因为这在技术上是输入时间窗口文本框中的值。我怎么能阻止这种情况发生？我只是希望窗口关闭当前值以保持原样。注意如果用户在框中输入（例如3），也会发生这种情况，即使用户点击取消，默认值也会替换为3。

这是WPF：

<Window x:Class="WpfClient.StaleTimeDialog"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Stale Time" FontFamily="Arial" Width="450" Height="300" Topmost="True" WindowStartupLocation="CenterScreen" ResizeMode="NoResize">
<Grid>
    <Grid.RowDefinitions>
    <RowDefinition Height="Auto"></RowDefinition>
    <RowDefinition Height="Auto"></RowDefinition>
    <RowDefinition Height="Auto"></RowDefinition>
    <RowDefinition Height="*"></RowDefinition>
    </Grid.RowDefinitions>

    <Label Margin="10" FontSize="16">Enter new Stale Time</Label>

    <StackPanel Grid.Row="1" Orientation="Horizontal" HorizontalAlignment="Center" Margin="0, 10, 10, 0">
        <TextBox Name="StaleTime" FontSize="20" Width="150" HorizontalAlignment="Left" VerticalContentAlignment="Center" Text="" AcceptsReturn="False" DataContext="{Binding}" PreviewTextInput="StaleTime_PreviewTextInput"></TextBox>
        <Label Width="Auto" FontSize="20" Height="Auto" VerticalContentAlignment="Center">Seconds</Label>
    </StackPanel>


    <StackPanel Grid.Row="3" HorizontalAlignment="Right" VerticalAlignment="Bottom" Orientation="Horizontal">
        <Button Name="SaveButton" Margin="10,10,10,10" Style="{StaticResource controlButtonStyle}" IsDefault="True" Click="SaveButton_Click">Save</Button>
        <Button Name="CancelButton" Margin="10,10,10,10" Style="{StaticResource controlButtonStyle}" IsCancel="True" Click="CancelButton_Click">Cancel</Button>
    </StackPanel>

</Grid>

这是C＃：

public partial class StaleTimeDialog : Window
{
    private Client client = null;
    private SystemStatus systemStatus = null;
    private UserTypes userType = UserTypes.Unknown;
    private bool isStandaloneGUI = false;
    private static string CurrentValue = "";

    public StaleTimeDialog()
    {
        InitializeComponent();

        CurrentValue = StaleTime.Text;

    }
    private void Cancel_Click(object sender, EventArgs e)
    {
        StaleTime.Text = CurrentValue.ToString();
        CancelButton.IsCancel = true;
        this.Close();

    }

    private void StaleTime_KeyPress(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
        {
            e.Handled = true;


        }
    }
    private void SaveButton_Click(object sender, RoutedEventArgs e)
    {
        if (true)
        {

            this.Close();
        }
        else
        {
            ErrorDialog errorDialog = new ErrorDialog(DialogType.OKDialog, IconType.Warning, "Save failed");

            errorDialog.ShowDialog();
        }
    }
    private void StaleTime_PreviewTextInput(object sender, TextCompositionEventArgs e)
    {
        CheckIsNumeric(e);
    }

    private void CheckIsNumeric(TextCompositionEventArgs e)
    {
        int result;

        if (!(int.TryParse(e.Text, out result) || e.Text == "."))
        {
            e.Handled = true;
        }
    }

    private void CancelButton_Click(object sender, RoutedEventArgs e)
    {
        this.DialogResult = false;
        StaleTime.Undo();
    }

}

这是在C＃中调用它的实例：

    private void EditParametersButton_Click(object sender, RoutedEventArgs e)
    {
        StaleTimeDialog staletimeDialog = new StaleTimeDialog();

        bool? result = staletimeDialog.ShowDialog();

        if (staletimeDialog.StaleTime.Text.Equals("") || staletimeDialog.StaleTime.Text.Equals(" "))
        {
            App.ChipStale = DefaultStaleTime;
        }
        else
        {
            App.ChipStale = Convert.ToInt32(staletimeDialog.StaleTime.Text);
        }
        FoodParametersLine4Run.Text = App.ChipStale.ToString();

    }

Answer 1

您需要将TextBox模式下的Text TwoWay属性绑定到支持该视图DataContext中的更改通知的公共属性（通常是ViewModel）并设置UpdateSourceTrigger到LostFocus或Explicit。

一旦你这样做，你所有的问题都将消失，作为奖励，你将摆脱所有丑陋的代码隐藏......这就是WPF的做事方式。

取消按钮写入文本框

1 个答案: