这个问题可能很简单,但是我找不到办法做,所以我问了。
我在我的模型中使用 IDataErrorInfo 来验证它如下:
public class Group : INotifyPropertyChanged, IDataErrorInfo
{
//Fileds & Properties
public string Error
{
get { return String.Empty; }
}
public string this[string columnName]
{
get
{
if (columnName == "GroupName")
{
bool _IsDuplicateGroupName;
using (MunimPlusContext context = new MunimPlusContext())
{
_IsDuplicateGroupName = context.GroupSet.Any(x => x.GroupName.ToLower() == GroupName.ToLower());
}
if (String.IsNullOrWhiteSpace(GroupName))
{
return "Group Name cannot be Empty.";
}
else if (_IsDuplicateGroupName)
{
return "Duplicate Group Name. Please choose a unique Group Name.";
}
}
if (columnName == "ParentId")
{
if (ParentId == null)
{
return "Please select Under Group under which " + (GroupName == null ? "this" : GroupName) + " Group will appear.";
}
else if (ParentId <= 0)
{
return "Please select a valid GroupName from the list.";
}
}
if (columnName == "NatureOfGroupId")
{
Group _PrimaryGroup;
using (MunimPlusContext context = new MunimPlusContext())
{
_PrimaryGroup = context.GroupSet.Where(x => x.GroupName == "Primary").FirstOrDefault();
}
if (_PrimaryGroup.GroupId == ParentId)
{
if (NatureOfGroupId == null)
{
return "Please select the Nature of Group.";
}
else if (NatureOfGroupId <= 0)
{
return "Please select a valid Nature of Group from the list.";
}
}
}
return String.Empty;
}
}
}
现在,在我的 XAML 中:
<Grid.Resources>
<DataTemplate DataType="{x:Type ValidationError}">
<TextBlock FontStyle="Italic" Foreground="Red" HorizontalAlignment="Right" Text="{Binding ErrorContent}" Margin="4,0,4,4" />
</DataTemplate>
</Grid.Resources>
<TextBlock Grid.Row="3" Grid.Column="1" Text="Name" />
<TextBlock Grid.Row="3" Grid.Column="1" Text=":" />
<TextBox Grid.Row="3" Grid.Column="2" x:Name="txtGroupName" Text="{Binding GroupName, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}"/>
<ContentPresenter Grid.Row="4" Grid.Column="2" Content="{Binding ElementName=txtGroupName, Path=(Validation.Errors).CurrentItem}" />
<TextBlock Grid.Row="5" Grid.Column="1" Text="Alias" />
<TextBlock Grid.Row="5" Grid.Column="1" Text=":" />
<TextBox Grid.Row="5" Grid.Column="2" x:Name="txtAlias" Text="{Binding Alias, ValidatesOnDataErrors=True}"/>
<ContentPresenter Grid.Row="6" Grid.Column="2" Content="{Binding ElementName=txtAlias, Path=(Validation.Errors).CurrentItem}" />
<TextBlock Grid.Row="7" Grid.Column="1" Text="Under" />
<TextBlock Grid.Row="7" Grid.Column="1" Text=":" />
<ComboBox Grid.Row="7" Grid.Column="2" x:Name="cmbParentGroup"
ItemsSource="{DynamicResource Items}" SelectedValue="{Binding ParentId, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}"
SelectedValuePath="Group.GroupId" Grid.IsSharedSizeScope="True" TextSearch.TextPath="Group.GroupName" LostFocus="cmbParentGroup_LostFocus"/>
<ContentPresenter Grid.Row="8" Grid.Column="2" Content="{Binding ElementName=cmbParentGroup, Path=(Validation.Errors).CurrentItem}" />
<TextBlock Grid.Row="9" Grid.Column="1" Text="Nature Of Group" />
<TextBlock Grid.Row="9" Grid.Column="1" Text=":" />
<ComboBox Grid.Row="9" Grid.Column="2" x:Name="cmbNatureOfGroup"
ItemsSource="{Binding DataContext.NaturesOfGroup, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type core:UserControlViewBase}}}"
DisplayMemberPath="Nature" SelectedValue="{Binding NatureOfGroupId, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}"
SelectedValuePath="NatureOfGroupId" LostFocus="cmbNatureOfGroup_LostFocus"/>
<ContentPresenter Grid.Row="10" Grid.Column="2" Content="{Binding ElementName=cmbNatureOfGroup, Path=(Validation.Errors).CurrentItem}" />
<StackPanel Grid.Row="11" Grid.Column="2" Orientation="Horizontal" HorizontalAlignment="Right">
<Button Content="Save" Style="{StaticResource SaveButtonWithText}"
Command="{Binding DataContext.SaveCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type core:UserControlViewBase}}}"/>
<Button Content="Cancel" Style="{StaticResource CancelButtonWithText}"
Command="{Binding DataContext.CancelCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type core:UserControlViewBase}}}"/>
</StackPanel>
现在,当我将数据保存到数据库时,我想检查我的模型是否有效。我该怎么做?
最佳答案
终于从this得到了我的答案发布。
这是我的 IDataErrorInfo 实现代码:
public string Error
{
get { return null; }
}
public string this[string propertyName]
{
get { return GetValidationError(propertyName); }
}
private static readonly string[] ValidatedProperties = { "GroupName", "ParentId", "NatureOfGroupId" };
public bool IsValid
{
get
{
foreach (string property in ValidatedProperties)
{
if (GetValidationError(property) != null)
{
return false;
}
}
return true;
}
}
private string GetValidationError(string propertyName)
{
string error = null;
switch (propertyName)
{
case "GroupName":
bool _IsDuplicateGroupName;
using (MunimPlusContext context = new MunimPlusContext())
{
_IsDuplicateGroupName = context.GroupSet.Any(x => x.GroupName.ToLower() == GroupName.ToLower());
}
if (String.IsNullOrWhiteSpace(GroupName))
{
error = "Group Name cannot be Empty.";
}
else if (_IsDuplicateGroupName)
{
error = "Duplicate Group Name. Please choose a unique Group Name.";
}
break;
case "ParentId":
if (ParentId == null)
{
error = "Please select Under Group under which " + (GroupName == null ? "this" : GroupName) + " Group will appear.";
}
else if (ParentId <= 0)
{
error = "Please select a valid GroupName from the list.";
}
break;
case "NatureOfGroupId":
Group _PrimaryGroup;
using (MunimPlusContext context = new MunimPlusContext())
{
_PrimaryGroup = context.GroupSet.Where(x => x.GroupName == "Primary").FirstOrDefault();
}
if (_PrimaryGroup.GroupId == ParentId)
{
if (NatureOfGroupId == null)
{
error = "Please select the Nature of Group.";
}
else if (NatureOfGroupId <= 0)
{
error = "Please select a valid Nature of Group from the list.";
}
}
break;
}
return error;
}
下面是我如何检查是否所有属性都对名为 CurrentGroup 的对象有效?
if (CurrentGroup.IsValid)
{
//save data to the database.......
}
https://stackoverflow.com/questions/29356839/