最终解决方案：

Question

我有一个ViewModel，它使用IDataErrorInfo接口处理验证。这适用于ComboBoxes，TextBoxes，Checkboxes等。

DatePicker似乎根据绑定到＆＃34; DateTime？＆＃34;验证输入本身？ ViewModel中的属性也可以正常工作。

现在我想在ViewModel中使用Command Binding来禁用/启用按钮。如果任何Control显示验证错误，则应禁用Button。

使用MVVM-Light的RelayCommand除了DatePickers之外，我还可以使用它，因为它们可以验证自己。

RelayCommand Code：

this.DoSomethingCommand = new RelayCommand(this.DoSomething, this.CanDoSomething);

有没有办法让他们的验证状态进入ViewModel？
我真的很感激这方面的一些帮助！

在任何人提到它之前：我已经尝试过使用Multidatatrigger，因此在视图中处理按钮IsEnabled属性。它没有用，IsEnabled是唯一一个我无法使用datatriggers改变的属性。即使没有任何CommandBindings。（也许是因为我的公司认证框架）

这是我试过的DataTrigger代码：

    <Button x:Uid="Button_1"
            Content="DoSomething"
            IsDefault="True"
            Command="{Binding DoSomethingCommand}">

        <Button.Style>
            <Style x:Uid="Style_1"
                   TargetType="{x:Type Button}"
                   BasedOn="{StaticResource {x:Type Button}}">
                <Setter x:Uid="Setter_2"
                        Property="IsEnabled"
                        Value="false" />
                <Style.Triggers>
                    <MultiDataTrigger x:Uid="MultiDataTrigger_1">
                        <MultiDataTrigger.Conditions>
                            <Condition x:Uid="Condition_1"
                                       Binding="{Binding (Validation.HasError), ElementName=ComboBox1}"
                                       Value="false" />
                            <Condition x:Uid="Condition_2"
                                       Binding="{Binding (Validation.HasError), ElementName=ComboBox2"
                                       Value="false" />
                            <Condition x:Uid="Condition_3"
                                       Binding="{Binding (Validation.HasError), ElementName=ComboBox3}"
                                       Value="false" />
                            <Condition x:Uid="Condition_4"
                                       Binding="{Binding (Validation.HasError), ElementName=ComboBox4}"
                                       Value="false" />
                            <Condition x:Uid="Condition_5"
                                       Binding="{Binding (Validation.HasError), ElementName=ComboBox5}"
                                       Value="false" />
                            <Condition x:Uid="Condition_6"
                                       Binding="{Binding (Validation.HasError), ElementName=DatePicker1}"
                                       Value="false" />
                            <Condition x:Uid="Condition_7"
                                       Binding="{Binding (Validation.HasError), ElementName=DatePicker2}"
                                       Value="false" />
                        </MultiDataTrigger.Conditions>
                        <Setter x:Uid="Setter_1"
                                Property="IsEnabled"
                                Value="True" />
                    </MultiDataTrigger>
                </Style.Triggers>
            </Style>
        </Button.Style>
    </Button>

Answer 1

请试试这个：在Xaml：

  <Grid> 
    <Button IsDefault="True" Content="Login" Height="27" Width="75" CommandParameter="{Binding ElementName=XXXXXXXX}" Command="{Binding LoginCommand, Source={StaticResource LoginController}}" Grid.Column="1" Grid.Row="7"/>

    <Button Content="Cancel" Height="27" Width="75" Grid.Column="3" Grid.Row="7" IsCancel="True">
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="Click">
                <i:InvokeCommandAction Command="{Binding CancelCommand,Source={StaticResource LoginController}}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
    </Button>
    <Label Foreground="White" Content="User Name:" Grid.Column="1" Grid.Row="1"/>
    <Label Foreground="White" Content="Password:" Grid.Column="1" Grid.Row="3"/>
    <TextBox x:Name="UserName" HorizontalAlignment="Left" Width="130" Height="27" Grid.Column="3" Grid.Row="1" Text="{Binding UserName, Source={StaticResource LoginController}, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=true, NotifyOnValidationError=true}"/>
    <PasswordBox HorizontalAlignment="Left" Width="130" Height="27" w:PasswordHelper.Attach="True" 
     w:PasswordHelper.Password="{Binding Password,Source={StaticResource LoginController}, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=true, NotifyOnValidationError=true}" Grid.Column="3" Grid.Row="3" />        
</Grid>

在ViewModel中：

     public ICommand LoginCommand
    {
        get
        {
            return new RelayCommand(OnLogin, IsEnable);
        }
    }
 public void OnLogin(object param)
    {
        //code
    }
bool IsEnable(object obj)
    {
           //Code for you button enable for example "return false;"
    }

希望这会对你有所帮助。

Answer 2

最终解决方案：

我根据需要使用以下代码：

查看：

<Button x:Uid="Button_1" Content="DoSomething" IsDefault="True" Command="{Binding DoSomethingCommand}"> <Button.CommandParameter> <MultiBinding x:Uid="MultiBinding_1" Converter="{StaticResource validationConverter}"> <Binding x:Uid="Binding_1" ElementName="ComboBox1" Path="(Validation.HasError)" /> <Binding x:Uid="Binding_2" ElementName="ComboBox2" Path="(Validation.HasError)" /> <Binding x:Uid="Binding_3" ElementName="ComboBox3" Path="(Validation.HasError)" /> <Binding x:Uid="Binding_4" ElementName="ComboBox4" Path="(Validation.HasError)" /> <Binding x:Uid="Binding_5" ElementName="ComboBox5" Path="(Validation.HasError)" /> <Binding x:Uid="Binding_6" ElementName="DatePicker1" Path="(Validation.HasError)" /> <Binding x:Uid="Binding_7" ElementName="DatePicker2" Path="(Validation.HasError)" /> </MultiBinding> </Button.CommandParameter> </Button>

ValidationConverter：

public class ValidationConverter : IMultiValueConverter { public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture) { foreach (var item in values) { if ((bool)item == true) { return true; } } return false; } public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture) { List<object> list = new List<object>(); foreach (var item in targetTypes) { list.Add(Binding.DoNothing); } return list.ToArray(); } }

ViewModel中的CanExecute方法：

private bool CanDoSomething(object obj) { return !(bool)obj; }

使用MVVM基于WPF DatePicker验证禁用/启用按钮

2 个答案:

最终解决方案：