WPF验证取决于必填/非必填字段
本文关键字：字段 验证 WPF 取决于 | 更新日期: 2023-09-27 18:18:41
我对WPF的发展不熟悉，但我正在考虑如何一石三鸟。示例:我有一个表单2 TextBox和2 textblock。第一个"鸟"将能够"丰富"一些文本块与星号，如果他们引用必填字段:
<TextBlock Grid.Row="0" Grid.Column="0" Text="Age" customProperty="Required" />
<TextBlock Grid.Row="1" Grid.Column="0" Text="Foot Size/>
那么textblock将以不同的方式显示它们的文本，第一个将有一个星号，而没有定义自定义属性的textblock将没有。
第二种方法是对文本框的值进行某种验证，如果我理解正确的话，这是通过使用CustomValidationRule来完成的，我为此实现了一个类:class AgeController: ValidationRule
{
public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
{
if (value == null)
return new ValidationResult(false, "Null value");
int temp = 1;
Boolean noIllegalChars = int.TryParse(value.ToString(), out temp);
if (temp >= 1)
return new ValidationResult(true, null);
else
return new ValidationResult(false, "Correggi");
}
}
通过将此添加到textBlox XAML代码:
<TextBox.Text>
<Binding Path="blabla" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True">
<Binding.ValidationRules>
<local:AgeController ValidationStep="RawProposedValue" />
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
这是有效的，但是对于必填字段和非必填字段的验证过程应该是不同的:如果它是必需的，则空白输入无效，但如果它是可选的，则空白输入是可以的。我如何实现这一点，而不指定两个不同的ValidationRule，同时引用链接到文本框的文本块?
/tldr:我正在尝试找到一种方法，用一个属性来丰富文本块，该属性可以为其文本添加样式(星号或任何客户端想要的，我修改了浓缩修改文本的方式，只在一个地方)，然后，引用浓缩文本块的文本框的验证将根据浓缩的值表现不同。
我希望我没有把解释弄乱。
1。TextBlock没有ControlTemplate属性。所以(*)所需的不能添加到TextBlock
Label有一个控制模板，可以将焦点放在输入字段上。让我们用它。
按下Alt+F时，Target属性传递焦点到TextBox的用法:
<!-- Prefixing Firstname with _ allows the user to give focus
to the textbox (Target) by pressing Alt + F-->
<local:LabelWithRequiredInfo Content="_Firstname"
IsRequired="false"
Target="{Binding ElementName=textboxFirstname,
Mode=OneWay}" ... />
创建Label: LabelWithRequiredInfo的子类，这样就可以添加一个IsRequired属性。
(使用VS添加新项目/WPF自定义控件)。
2。为控件创建IsRequired依赖属性，以便绑定工作——我们需要它!
public class LabelWithRequiredInfo : Label
{
public bool IsRequired
{
get { return (bool)GetValue(IsRequiredProperty); }
set { SetValue(IsRequiredProperty, value); }
}
// Using a DependencyProperty as the backing store for IsRequired. This enables animation, styling, binding, etc...
public static readonly DependencyProperty IsRequiredProperty =
DependencyProperty.Register("IsRequired", typeof(bool), typeof(LabelWithRequiredInfo), new PropertyMetadata(false));
static LabelWithRequiredInfo()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(LabelWithRequiredInfo), new FrameworkPropertyMetadata(typeof(LabelWithRequiredInfo)));
}
}
3。让我们在Themes'Generic中填充LabelWithRequiredInfo模板。xaml
(但是模板首先是在MainWindow中设计的。xaml右键单击标签/编辑模板/复制-因此它可以可视化-然后模板内容复制到Generic.xaml)
<Style TargetType="{x:Type local:LabelWithRequiredInfo}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:LabelWithRequiredInfo}">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true">
<!-- A grid has been added to the template content to have multiple content. -->
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="30"/>
</Grid.ColumnDefinitions>
<ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
<!-- The Visibility property has to be converted because it's not a bool but has a Visibility type
The converter (pretty classical) can be found in the attached solution, and is declared in the resource section
The binding is made on a property of the component : IsRequired
-->
<TextBlock Text="(*)"
Visibility="{TemplateBinding IsRequired,Converter={StaticResource booleanToVisibilityConverter}}"
Foreground="Red"
Grid.Column="1"
Margin="5 0"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
4。转换器的通用声明。
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:TextboxRequiredMandatoryInput">
<local:BooleanToVisibilityConverter x:Key="booleanToVisibilityConverter"/>
5。考虑IsRequired行为的ValidationRule声明:
class RequiredValidationRule : ValidationRule
{
public bool IsRequired { get; set; }
public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
{
var content = value as String;
if (content != null)
{
if (IsRequired && String.IsNullOrWhiteSpace(content))
return new ValidationResult(false, "Required content");
}
return ValidationResult.ValidResult;
}
}
6。并在你的绑定中使用它，如你所见:
<TextBox x:Name="textboxFirstname" HorizontalAlignment="Left" Height="23" Margin="236,94,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120">
<TextBox.Text>
<Binding Path="Firstname" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True">
<Binding.ValidationRules>
<local:RequiredValidationRule IsRequired="true" ValidationStep="RawProposedValue" />
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
你会在这里找到完整的解决方案:
http://1drv。ms/1igpsyb
对于可重用性和您描述需求的方式，可能需要一个聚合控件。我认为一个UserControl +一些DependencyProperty是一个完美的。
对于我的UserControl，我将像这样…
<UserControl x:Class="WpfApplication1.InputFieldControl"
x:Name="InputUserCtrl"
... >
<StackPanel x:Name="MainPanel">
<TextBlock x:Name="Label">
<TextBlock.Text>
<MultiBinding StringFormat="{}{0}{1}:">
<Binding Path="InputLabel" ElementName="InputUserCtrl"/>
<Binding Path="RequiredStringSymbol" ElementName="InputUserCtrl"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
<TextBox x:Name="Value" Text="{Binding DataContext, ElementName=InputUserCtrl}"/>
</StackPanel>
然后在它的部分类上(我已经添加了一些属性，参考用法部分):
public partial class InputFieldControl : UserControl
{
// Required property
public static readonly DependencyProperty RequiredProperty =
DependencyProperty.Register("Required",
typeof(bool), typeof(InputFieldControl),
new PropertyMetadata(true, OnRequiredChanged));
private static void OnRequiredChanged(DependencyObject d, DependencyPropertyChangedEventArgs e){
InputFieldControl ctrl = d as InputFieldControl;
// symbol is voided
if ((bool)e.NewValue == false)
ctrl.RequiredStringSymbol = string.Empty;
}
public bool Required {
get { return (bool)GetValue(RequiredProperty); }
set { SetValue(RequiredProperty, value); }
}
// Required string symbol
public static readonly DependencyProperty RequiredStringSymbolProperty =
DependencyProperty.Register("RequiredStringSymbol",
typeof(string), typeof(InputFieldControl),
new PropertyMetadata("*"));
public string RequiredStringSymbol{
get { return (string)GetValue(RequiredStringSymbolProperty); }
set { SetValue(RequiredStringSymbolProperty, value); }
}
// Input Label
public static readonly DependencyProperty InputLabelProperty =
DependencyProperty.Register("InputLabel",
typeof(string), typeof(InputFieldControl),
new PropertyMetadata(string.Empty));
public string InputLabel{
get { return (string)GetValue(InputLabelProperty); }
set { SetValue(InputLabelProperty, value); }
}
我可以像这样使用控件:
<StackPanel>
<customCtrl:InputFieldControl Required="True"
RequiredStringSymbol="+"
InputLabel="RequiredField"/>
<customCtrl:InputFieldControl Required="False"
InputLabel="NormalField"/>
<customCtrl:InputFieldControl Required="True"
RequiredStringSymbol="*"
InputLabel="AnotherRequiredField">
</customCtrl:InputFieldControl>
</StackPanel>
至于验证部分，我宁愿使用IDataErrorInfo。这可以与ViewModel一起使用，因为我们现在可以绑定Required属性。
第一点:您可以为您的控件定义一个自定义模板，您可以在其中添加您想要的视觉元素(星号等)。您可以使用触发器控制它们的可见性。(你可以问一个单独的问题来了解更多细节)
Second/Third:您可以在AgeController上定义一个布尔属性IsRequired，并且您可以在定义验证时将其设置为TRUE/FALSE:
<TextBox.Text>
<Binding Path="blabla" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True">
<Binding.ValidationRules>
<local:AgeController ValidationStep="RawProposedValue"
IsRequired="**True**" />
OR: IsRequired="**False**" />
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
那么，在实现验证时，这个值将对您可用:
public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
{
if (IsRequired)
{
...
}
else
{
...
}
}
这是第二个答案，它并不完全是Massimo的问题。
我这样做了，认为对于XAML设计器
来说更容易使用。目标是使Label(子类实际上具有所需的红色符号(*))更易于使用。
它给予焦点 TexBlock由于通常的Target属性
<local:LabelWithRequiredInfo Content="_Firstname"
Target="{Binding ElementName=textboxFirstname, Mode=OneWay}"
... />
并且因为有一个目标，LabelWithRequiredInfo可以检查TextBox.TextProperty中RequiredValidationRule的存在。
所以大多数时候不需要IsRequired属性。
public LabelWithRequiredInfo()
{
var dpd = DependencyPropertyDescriptor.FromProperty(Label.TargetProperty, typeof(Label));
dpd.AddValueChanged(this, SearchForRequiredValidationRule);
}
private void SearchForRequiredValidationRule(object sender, EventArgs e)
{
var textbox = Target as TextBox;
if (textbox != null)
{
Binding binding = BindingOperations.GetBinding(textbox, TextBox.TextProperty);
var requiredValidationRule = binding.ValidationRules
.OfType<RequiredValidationRule>()
.FirstOrDefault();
if (requiredValidationRule != null)
{
// makes the required legend (red (*) for instance) to appear
IsRequired = true;
}
}
}
如果必须在复选框或组合框上提供必需的图例，那么在LabelWithRequiredInfo上仍然有一个IsRequired属性
<local:LabelWithRequiredInfo Content="_I agree with the terms of contract"
Target="{Binding ElementName=checkboxIAgree}"
IsRequired='"true"
... />
并且仍然可以在文本框(或任何控件)上添加其他验证规则来检查数字，正则表达式，…
最后，将RequiredLegend设置为LabelWithRequiredInfo: 中的依赖属性。public Object RequiredLegend
{
get { return (Object)GetValue(RequiredLegendProperty); }
set { SetValue(RequiredLegendProperty, value); }
}
// Using a DependencyProperty as the backing store for RequiredLegend. This enables animation, styling, binding, etc...
public static readonly DependencyProperty RequiredLegendProperty =
DependencyProperty.Register("RequiredLegend", typeof(Object), typeof(LabelWithRequiredInfo), new PropertyMetadata(null));
以便模板LabelWithRequiredInfo可以使用它来显示一些文本:
<local:LabelWithRequiredInfo RequiredLegend="(*)" ... />
或者更像xml的东西:
<local:LabelWithRequiredInfo ... >
<local:LabelWithRequiredInfo.RequiredLegend>
<TextBlock Text="(*)" Foreground="Red" />
</local:LabelWithRequiredInfo.RequiredLegend>
只需更改themes'Generic.xaml中的控件模板即可。
它现在使用ContentControl来显示文本或控件:
<Style TargetType="{x:Type local:LabelWithRequiredInfo}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:LabelWithRequiredInfo}">
<Border ...>
<Grid>
<Grid.ColumnDefinitions ... />
<ContentPresenter ... />
**<ContentControl Content="{TemplateBinding RequiredLegend}" Visibility="{TemplateBinding IsRequired,Converter={StaticResource booleanToVisibilityConverter}}" Grid.Column="1" /> **
</Grid>
这是完整工作解决方案的链接:http://1drv.ms/1MxltVZ
最佳编码