制作一个按钮IsEnabled的状态取决于两个文本框 [英] Making a Button IsEnabled state depend on two textboxes

问题描述

我想有一个按钮的IsEnabled仅是真实的，如果两个文本框没有任何错误（在这种情况下，我只希望他们都为数字）

我试过文本框设置为NotifyOnValidationError = TRUE，以为这将提高该冒泡到容器控件例外 - 我会再设置按钮的IsEnabled为true基础上，Validation.HasError附加属性属于该控制

我尝试了以下（剥离的格式code），但它不工作（使能当我第一次启动应用程序的按钮和文本输入框是空的 - 他们必然要为空的小数）

 ＆LT; WrapPanel中＆GT;
    ＆LT;文本框X：名称=txtDeltaMin文本={绑定路径= DeltaMinFilter，NotifyOnValidationError = TRUE，ValidatesOnDataErrors = TRUE，ValidatesOnExceptions = TRUE}＆GT;＆LT; /文本框＆GT;
    ＆LT;文本框X：名称=txtDeltaMax文本={绑定路径= DeltaMaxFilter，NotifyOnValidationError = TRUE，ValidatesOnDataErrors = TRUE，ValidatesOnExceptions = TRUE}＆GT;＆LT; /文本框＆GT;
    ＆LT;按钮X：名称=btnUpdateFilter点击=btnUpdateFilter_Click的IsEnabled ={绑定的RelativeSource = {的RelativeSource模式= FindAncestor，AncestorType = {X：类型WrapPanel中}}，路径=（Validation.HasError）}过滤器过滤＆LT ; /按钮＆GT;
＆LT; / WrapPanel中＆GT;
 

解决方案

您可以使用的 MultiBinding 。看起来应该是这样的：

 ＆LT;文本框文本={绑定路径= DeltaMinFilter，NotifyOnValidationError = TRUE，ValidatesOnDataErrors = TRUE，ValidatesOnExceptions = TRUE}/＆GT;
＆LT;文本框X：名称=txtDeltaMax文本={绑定路径= DeltaMaxFilter，NotifyOnValidationError = TRUE，ValidatesOnDataErrors = TRUE，ValidatesOnExceptions = TRUE}/＆GT;
＆LT;按钮X：名称=btnUpdateFilter点击=btnUpdateFilter_ClickCONTENT =过滤器＆GT;
    ＆LT; Button.IsEnabled＆GT;
        ＆LT; MultiBinding转换器={的StaticResource IsEnabledConverter}＆GT;
            ＆LT;绑定的ElementName =txtDeltaMin路径=Validation.HasError/＆GT;
            ＆LT;绑定的ElementName =txtDeltaMax路径=Validation.HasError/＆GT;
        ＆LT; / MultiBinding＆GT;
    ＆LT; /Button.IsEnabled>
＆LT; /按钮＆GT;
 

然后你只需要做的 IsEnabledConverter 的通过实施的 IMultiValueConverter 的，并将其添加为一个资源。类

 公共类IsEnabledConverter：IMultiValueConverter
{
    公共对象转换（对象[]值，类型TARGETTYPE，对象参数，System.Globalization.CultureInfo文化）
    {
        的foreach（中值VAR的isValid）
            如果（IsValid的是布尔？==假）
                返回false;
        返回true;
    }

    公共对象[] ConvertBack（对象的值，类型[] targetTypes，对象参数，System.Globalization.CultureInfo文化）
    {
        抛出新的NotImplementedException（）;
    }
}
 

I want to have a button's IsEnabled to only be true if two textboxes don't have any errors (in this case, I just want them to both be numeric)

I tried setting the textboxes to NotifyOnValidationError=True, thinking this will raise an exception that bubbles up to a container control - I would then set the Button's IsEnabled to true based on the Validation.HasError attached property belonging to that control

I tried the following (stripped of formatting code) but it's not working (the button is enabled when I first start the application and the textboxes are empty - they are bound to nullable decimals)

<WrapPanel>
    <TextBox x:Name="txtDeltaMin"Text="{Binding Path=DeltaMinFilter, NotifyOnValidationError=True, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}"></TextBox>
    <TextBox x:Name="txtDeltaMax" Text="{Binding Path=DeltaMaxFilter, NotifyOnValidationError=True, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}"></TextBox>
    <Button x:Name="btnUpdateFilter" Click="btnUpdateFilter_Click" IsEnabled="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type WrapPanel}}, Path=(Validation.HasError)}">Filter</Button>
</WrapPanel>

解决方案

You can use a MultiBinding. Should look something like this:

<TextBox Text="{Binding Path=DeltaMinFilter, NotifyOnValidationError=True, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" />
<TextBox x:Name="txtDeltaMax" Text="{Binding Path=DeltaMaxFilter, NotifyOnValidationError=True, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" />
<Button x:Name="btnUpdateFilter" Click="btnUpdateFilter_Click" Content="Filter">
    <Button.IsEnabled>
        <MultiBinding Converter="{StaticResource IsEnabledConverter}">
            <Binding ElementName="txtDeltaMin" Path="Validation.HasError" />
            <Binding ElementName="txtDeltaMax" Path="Validation.HasError" />
        </MultiBinding>
    </Button.IsEnabled> 
</Button>

Then you just need to make the IsEnabledConverter class by implementing IMultiValueConverter, and add it as a resource.

public class IsEnabledConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        foreach (var isValid in values)
            if (isValid as bool? == false) 
                return false;
        return true;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

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