我有一个带有绑定的按钮，ClearCommand它可以清除文本框的值，但它不起作用。
public SellerDetailsViewModel() //constructor
{
sdObject = new SellerDetailsTable();
_SaveCommand = new RelayCommand(Save, CanSave);
_ClearCommand = new RelayCommand(clear, Canclear);
}
private readonly ICommand _ClearCommand;
public ICommand ClearCommand { get { return _ClearCommand; } }
public event PropertyChangedEventHandler PropertyChanged;
public void onPropertyChange(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
public bool Canclear(object obj)
{
return true;
}
public void clear(object obj)
{
this.PancardNumber = "";
this.ContactNumber = 0;
this.FirstName = "";
this.LastName = "";
this.MiddleName = "";
this.OtherDocument = "";
this.Address = "";
}
<Page x:Class="CarDealer.SellerDetails"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="800" d:DesignWidth="900"
xmlns:ViewModels="clr-namespace:CarDealer.PresentationLayer.ViewModel"
Title="SellerDetails">
<Page.Resources>
<ViewModels:SellerDetailsViewModel x:Key="ViewModel">
</ViewModels:SellerDetailsViewModel>
<ControlTemplate x:Key="TextBoxErrorTemplate">
<DockPanel LastChildFill="True">
<TextBlock DockPanel.Dock="Bottom" Foreground="Red" FontSize="10pt"
Text="{Binding ElementName=MyAdorner,Path=AdornedElement.(Validation.Errors)[0].ErrorContent}"/>
<Border BorderBrush="Red" BorderThickness="2" Width="225" Height="35" >
<AdornedElementPlaceholder Name="MyAdorner" />
</Border>
</DockPanel>
</ControlTemplate>
</Page.Resources>
<Grid DataContext="{Binding Source={StaticResource ViewModel}}">
<Label Content="Seller Details" Height="39" HorizontalAlignment="Left" Margin="27,25,0,0" Name="lblTitle" VerticalAlignment="Top" FontSize="22" FontWeight="Bold" FontFamily="Times New Roman" Foreground="#FF1313D8" Width="169" />
<Label Content="First Name" Height="28" HorizontalAlignment="Left" Margin="44,87,0,0" Name="lblCustName" VerticalAlignment="Top" FontSize="16" />
<Label Content="Address" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="461,253,0,0" Name="lblAdress" VerticalAlignment="Top" />
<Label Content="Pan Card Number" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="44,243,0,0" Name="lblPanCardNumber" VerticalAlignment="Top" />
<Label Content="Contact Number" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="44,320,0,0" Name="lblContactNumber" VerticalAlignment="Top" />
<Label Content="Handover Date" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="461,170,0,0" Name="label1" VerticalAlignment="Top" />
<Label Content="Other Document" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="44,399,0,0" Name="label2" VerticalAlignment="Top" />
<Button Content="Save" Height="37" Command="{Binding SaveCommand}" HorizontalAlignment="Left" Margin="299,543,0,0" Name="btnSave" VerticalAlignment="Top" Width="131" FontSize="22" />
<TextBox Height="33" Text="{Binding FirstName, Mode=TwoWay}" HorizontalAlignment="Left" Margin="205,92,0,0" Name="txtFirstName" VerticalAlignment="Top" Width="225" BorderThickness="2" FontSize="16" />
<Label Content="Last Name" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="44,165,0,0" Name="label3" VerticalAlignment="Top" />
<TextBox BorderThickness="2" Text="{Binding LastName, Mode=TwoWay}" Height="33" HorizontalAlignment="Left" Margin="205,170,0,0" Name="txtLastName" VerticalAlignment="Top" Width="225" FontSize="16" />
<TextBox BorderThickness="2" Text="{Binding PancardNumber, Mode=TwoWay}" Height="33" HorizontalAlignment="Left" Margin="205,248,0,0" Name="txtPanCard" VerticalAlignment="Top" Width="225" FontSize="16" />
<TextBox BorderThickness="2" Height="33" HorizontalAlignment="Left" Margin="205,325,0,0" Validation.ErrorTemplate="{StaticResource TextBoxErrorTemplate}" Name="txtcontactNumber" VerticalAlignment="Top" Width="225" FontSize="16">
<TextBox.Text>
<Binding Path="ContactNumber">
<Binding.ValidationRules>
<ExceptionValidationRule/>
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
<TextBox Height="126" Text="{Binding Address, Mode=TwoWay}" HorizontalAlignment="Left" Margin="627,248,0,0" Name="TxtAddress" VerticalAlignment="Top" Width="257" BorderThickness="2" FontSize="16" VerticalScrollBarVisibility="Visible" />
<TextBox BorderThickness="2" Text="{Binding OtherDocument, Mode=TwoWay}" Height="126" HorizontalAlignment="Left" Margin="205,399,0,0" Name="rchTxtOtherDoc" VerticalAlignment="Top" Width="257" FontSize="16" VerticalScrollBarVisibility="Visible" />
<DatePicker Height="33" Text="{Binding HandoverDate}" HorizontalAlignment="Left" Margin="627,170,0,0" Name="dtPickerHandoverDate" VerticalAlignment="Top" Width="225" FontSize="16" />
<Button Content="Clear All" Command="{Binding ClearCommand}" FontSize="22" Height="37" HorizontalAlignment="Left" Margin="500,543,0,0" Name="btnClearAll" VerticalAlignment="Top" Width="131" />
<Label Content="Middle Name" FontSize="16" Height="28" HorizontalAlignment="Left" Margin="471,87,0,0" Name="label4" VerticalAlignment="Top" />
<TextBox BorderThickness="2" Text="{Binding MiddleName, Mode=TwoWay}" FontSize="16" Height="33" HorizontalAlignment="Left" Margin="627,87,0,0" Name="txtMiddleName" VerticalAlignment="Top" Width="225" />
</Grid>
我已经调试了代码执行。clear函数已执行，但在视图中，文本框不为空。你能帮我弄清楚我做错了什么吗？
我已经添加了剩余的代码，请问缺少什么。