WP8 滑块的问题 [英] Problems with WP8 Slider

问题描述

我的 XAML:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition Width="auto"/>
    </Grid.ColumnDefinitions>
    <Slider Name="sldLength" Margin="0 0 0 0"  Grid.Column="0" 
            Minimum="5" Maximum="30" SmallChange="1"  LargeChange="1"
            Value="10" ValueChanged="sldLength_ValueChanged"/>
    <TextBlock Name="tblLength" Margin="0 10 5 0" Text="10" Grid.Column="1"
            FontSize="{StaticResource PhoneFontSizeMediumLarge}"/>
</Grid>

我的代码开始了:

private void sldLength_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    tblLength.Text = e.NewValue.ToString();
}

2个问题:

1. 在加载应用程序时触发 ValueChanged 事件，这不是问题，但由于某种原因，在事件触发时 tblLength 为 NULL 并且这会引发异常，我将其包装在 if 语句检查该 NULL，但这肯定不是问题吧?
2. Slider 不会以 1 的增量变化，即使 SmallChange 和 LargeChange 设置为 1.如何修复?

1. ValueChanged event fires when the application is loaded, this is not a problem, but for some reason at the time of the event firing tblLength is NULL and this throws an exception, I have wrapped it in an if statement checking for that NULL, but this surely should not be the issue right?
2. Slider does not change in the increments of 1, even though SmallChange and LargeChange are set to 1. How could that be fixed?

感谢您的帮助...

--编辑--

使用 Chepene 建议解决了问题 1.
用小丑事件处理程序解决了问题 2:

Solved problem 1 with Chepene suggestion.
Solved problem 2 with little cheeky event handler:

private void sldLength_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    ((Slider)sender).Value = Math.Round(((Slider)sender).Value);
}

推荐答案

您可以使用绑定.像这样:

You can use Bindings. Smth like this:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition Width="auto"/>
    </Grid.ColumnDefinitions>
    <Slider Name="sldLength" Margin="0 0 0 0"  Grid.Column="0" 
            Minimum="5" Maximum="30" SmallChange="1"  LargeChange="1"
            Value="10"/>
    <TextBlock Name="tblLength" Margin="0 10 5 0" Text="{Binding ElemantName=sldLength, Path=Value}" Grid.Column="1"
               FontSize="{StaticResource PhoneFontSizeMediumLarge}"/>
</Grid>

此处 tblLength 从 sldLength 的值中获取其文本.

Here tblLength takes its text from the value of sldLength.

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