wpf数据验证实例及常用方法小结
虽然标题是wpf数据验证，但并不是对IDataErrorInfo、ValidationRule、属性中throw Exception这几种验证方式的介绍；
之前做项目时(例如员工工资管理)，根据员工编号和年度月份验证 当月数据的唯一性，因为第一次开发wpf经验不足，所以用过几种不同的方式，并且现在用的这种方式也不是很满意，如果哪位大神有更好的办法 麻烦发个链接。
文章最后会把验证、列表的样式和验证中常使用的一些方法贴出来，方便大家使用；
列表页面 员工编号和年度月份验证
添加修改页面 填写编号选择月份后，验证不通过都是在编号处提示
一、言归正传，逐步写一下我当时的思路
1、为了实现这种需求的验证，最先想到的就是实现了ValidationRule的自定义验证类(ValidateExistLogName)能有一个属性(ValiByProperty) binding上月份中选择的值，关联月份和当前输入的员工编号来验证当月是否存在；
<Binding.ValidationRules>
<tool:ValidateExistLogName ValiByProperty="{Binding CurMonth}"/>
</Binding.ValidationRules>
但是只有DependencyObject派生类的DependencyProperty属性才能进行binding，于是我找到了给ValidationRule派生类的属性上binding的办法
参考链接：http://www.codeproject.com/Articles/18678/Attaching-a-Virtual-Branch-to-the-Logical-Tree-in
https://social.msdn.microsoft.com/Forums/vstudio/en-US/982e2fcf-780f-4f1c-9730-cedcd4e24320/binding-validationrules-property?forum=wpf
这种方式可能添加页面比较好实现，但是对于列表DataGrid恐怕binding起来就，也许有人说可以DataGrid的IsReadOnly=false，但是我的需求是修改页面修改的同时支持列表直接修改。
2、对实体类添加PropertyChangedEventHandler事件，这种方式可以实现，但是却不是在ValidationRule中验证，而且事件中的逻辑代码也稍较麻烦，因为e.PropertyName绑定的是datepicker控件时，需throw new Exception才能显示出来错误
列表中 初始化列表时遍历datagrid中的绑定源数据：
foreach (var item in data)
{
//为新加数据也加入事件
item.PropertyChanged -= new System.ComponentModel.PropertyChangedEventHandler(source_PropertyChanged);
item.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(source_PropertyChanged);
}
添加或者修改直接给绑定的实体类添加事件：
source.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(source_PropertyChanged);
3、期间还尝试了别的，但改动不大 基本记不清楚了，最后还是在派生自ValidationRule的类中添加需要验证的实体属性
public class ValidateExistCurMonthOrLogName : ValidationRule
{
public object Entity { get; set; }
public int ValiPropertyType { get; set; }//1验证LogName，2验证CurMonth
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
if(this.ValiPropertyType==1)
{
int tmp;
if (string.IsNullOrEmpty(value as string) || string.IsNullOrWhiteSpace(value as string))
{
return new ValidationResult(false, "不能为空！");
}
else if (!int.TryParse(value as string, out tmp))
{
return new ValidationResult(false, "请输入正确的数字！");
}
else if(...验证是否已存在)
.........
}
.........
}
}
1、DataGrid列表
//在单元格开始编辑的时候，把要验证的实体赋值
dataGrid.PreparingCellForEdit += delegate(object sender, DataGridPreparingCellForEditEventArgs e)
{
//记录原始状态
AllowanceData model = e.Row.Item as AllowanceData;
allowanceDataHelper.SourceToModel(model, originalModel);
//获取cell
DataGridCell cell = OperateControlHelper.GetCell(dataGrid, e.Row.GetIndex(), e.Column.DisplayIndex);
//判断当前编辑的是TextBox还是DatePicker
DatePicker dp = OperateControlHelper.GetVisualChild<DatePicker>(cell);
TextBox txb = OperateControlHelper.GetVisualChild<TextBox>(cell);
FrameworkElement node;
DependencyProperty depenPro;
if (dp != null)
{
node = dp;
depenPro = DatePicker.TextProperty;
}
else if (txb != null)
{
node = txb;
depenPro = TextBox.TextProperty;
}
else
{
throw new Exception("...");
}
InitValidateExistCurMonthOrLogName(node, new ValidateExistCurMonthOrLogName() { Entity = originalModel });
}
2、添加或修改页面直接调用
InitValidateExistCurMonthOrLogName(txbLogName, new ValidateExistCurMonthOrLogName() { Entity = source });
InitValidateExistCurMonthOrLogName(dpCurMonth, new ValidateExistCurMonthOrLogName() { Entity = source });
//调用
void InitValidateExistCurMonthOrLogName(FrameworkElement node, ValidateExistCurMonthOrLogName modelArgs)
{
//获取类型
DependencyProperty depenPro;
if (node is DatePicker)
{
depenPro = DatePicker.TextProperty;
}
else
{
depenPro = TextBox.TextProperty;
}
//获取自定义验证
ValidateExistCurMonthOrLogName validateLogNameOrCurMonth = node.GetBindingExpression(depenPro).ParentBinding.ValidationRules.Select(v =>
{
if (v is ValidateExistCurMonthOrLogName)
return v;
return null;
}).FirstOrDefault() as ValidateExistCurMonthOrLogName;
if (validateLogNameOrCurMonth != null)
{
validateLogNameOrCurMonth.Entity = modelArgs.Entity;
}
}
二、styel
1、列表的样式
<Style TargetType="DataGrid">
<Setter Property="AutoGenerateColumns" Value="False"/>
<!--<Setter Property="IsReadOnly" Value="True"/>-->
<Setter Property="VerticalAlignment" Value="Top"/>
<Setter Property="CanUserSortColumns" Value="False"/>
<Setter Property="CanUserResizeColumns" Value="False"/>
<Setter Property="CanUserResizeRows" Value="False"/>
<Setter Property="SelectionMode" Value="Extended"/>
<Setter Property="SelectionUnit" Value="FullRow"/>
<Setter Property="CanUserReorderColumns" Value="False"/>
<Setter Property="AlternationCount" Value="2"/>
<Setter Property="RowHeaderWidth" Value="0"/>
<Setter Property="CanUserAddRows" Value="False"/>
<Setter Property="CanUserResizeColumns" Value="false"/>
<Setter Property="Background" Value="#b7e9fe" />
<Setter Property="BorderBrush" Value="gray" />
<Setter Property="HorizontalGridLinesBrush">
<Setter.Value>
<SolidColorBrush Color="#85cfee"/>
</Setter.Value>
</Setter>
<Setter Property="VerticalGridLinesBrush">
<Setter.Value>
<SolidColorBrush Color="#85cfee"/>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="DataGridColumnHeader">
<Setter Property="SnapsToDevicePixels" Value="True" />
<Setter Property="MinWidth" Value="0" />
<Setter Property="MinHeight" Value="28" />
<Setter Property="Foreground" Value="#07638a" />
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="FontSize" Value="12" />
<Setter Property="Cursor" Value="Hand" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="DataGridColumnHeader">
<Border x:Name="BackgroundBorder" BorderThickness="0,1,0,1"
BorderBrush="#85cfee"
Width="Auto">
<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<ContentPresenter Margin="0,0,0,0" VerticalAlignment="Center" HorizontalAlignment="Center"/>
<Path x:Name="SortArrow" Visibility="Collapsed" Data="M0,0 L1,0 0.5,1 z" Stretch="Fill" Grid.Column="2" Width="8" Height="6" Fill="White" Margin="0,0,50,0"
VerticalAlignment="Center" RenderTransformOrigin="1,1" />
<Rectangle Width="1" Fill="#85cfee" HorizontalAlignment="Right" Grid.ColumnSpan="1" />
</Grid>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Height" Value="25"/>
</Style>
<Style TargetType="DataGridRow">
<Setter Property="Background" Value="#FFFFFF" />
<Setter Property="Height" Value="25"/>
<Setter Property="Foreground" Value="#07638a" />
<Style.Triggers>
<Trigger Property="AlternationIndex" Value="0" >
<Setter Property="Background" Value="#FFFFFF" />
</Trigger>
<Trigger Property="AlternationIndex" Value="1" >
<Setter Property="Background" Value="#e1f5fd" />
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="LightGray"/>
</Trigger>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Foreground" Value="Black"/>
</Trigger>
</Style.Triggers>
</Style>
2、DataGrid的ErrorTemplate
<Style x:Key="textBoxErrorTemplateInDataGrid" TargetType="{x:Type TextBox}">
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="BorderBrush" Value="#6bc4e9"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="MinWidth" Value="80"/>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<DockPanel LastChildFill="True">
<Ellipse DockPanel.Dock="Right"
Width="15" Height="15" Margin="-25,0,0,0" StrokeThickness="1" Fill="Red" >
<Ellipse.Stroke>
<LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
<GradientStop Color="#FFFA0404" Offset="0"/>
<GradientStop Color="#FFC9C7C7" Offset="1"/>
</LinearGradientBrush>
</Ellipse.Stroke>
</Ellipse>
<TextBlock DockPanel.Dock="Right" ToolTip="{Binding ElementName=errorHint,Path=AdornedElement.(Validation.Errors)[0].ErrorContent}"
Foreground="White" FontSize="11pt" Margin="-15,5,0,0" FontWeight="Bold">!
<TextBlock.Triggers>
</TextBlock.Triggers>
</TextBlock>
<Border BorderBrush="Red" BorderThickness="1">
<AdornedElementPlaceholder Name="errorHint" />
</Border>
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
3、添加修改的ErrorTemplate
<Style x:Key="datePickerErrorTemplate" TargetType="{x:Type DatePicker}">
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="BorderBrush" Value="#6bc4e9"/>
<Setter Property="Foreground" Value="#07638a"/>
<Setter Property="Margin" Value="5, 10, 0, 0"/>
<Setter Property="Width" Value="120"/>
<Setter Property="Height" Value="23"/>
<Setter Property="BorderThickness" Value="1"/>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<DockPanel LastChildFill="True">
<TextBlock DockPanel.Dock="Right" Margin="5,0,0,0" VerticalAlignment="Center" Foreground="Red" FontSize="12"
Text="{Binding ElementName=errorHint, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}">
</TextBlock>
<Border BorderBrush="Red" BorderThickness="1">
<AdornedElementPlaceholder Name="errorHint" />
</Border>
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
三、wpf验证中常用的方法
1、获取自定义验证类
public YourValidationRule GetValidationRule(FrameworkElement node,DependencyProperty depenPro)
{
YourValidationRule vr = node.GetBindingExpression(depenPro).ParentBinding.ValidationRules.Select(v =>
{
if (v is YourValidationRule )
return v; return null;
}).FirstOrDefault() as YourValidationRule ;
return vr;
}
2、递归判断是否有未通过验证的控件
public static bool IsHasError(DependencyObject node, out string errorMsg)
{
errorMsg = string.Empty;
if (node != null)
{
bool isValid = !Validation.GetHasError(node);
if (!isValid)
{
if (node is IInputElement)
if (((IInputElement)node).IsEnabled == true)
{
ValidationError ve = Validation.GetErrors(node).FirstOrDefault();
if (ve != null)
{
errorMsg = ve.ErrorContent.ToString();
}
Keyboard.Focus((IInputElement)node);
return false;
}
}
}
foreach (object subnode in LogicalTreeHelper.GetChildren(node))
{
if (subnode is DependencyObject)
{
if (IsHasError((DependencyObject)subnode, out errorMsg) == false) return false;
}
}
return true;
}
3、向控件中添加错误验证
public static void AddValidationError<T>(FrameworkElement fe, DependencyProperty dp, string errorMsg) where T : ValidationRule, new()
{
ValidationError validationError =
new ValidationError(new NotConvertInt(),
fe.GetBindingExpression(dp));
validationError.ErrorContent = "该用户在本月已存在数据！";
Validation.MarkInvalid(
fe.GetBindingExpression(dp),
validationError);
}
4、清空控件中的错误验证
public static void ClearValidationError(FrameworkElement fe, DependencyProperty dp)
{
Validation.ClearInvalid(fe.GetBindingExpression(dp));
}
5、从DataGrid获得Cell
public static DataGridCell GetCell(DataGrid dataGrid, int row, int column)
{
DataGridRow rowContainer = GetRow(dataGrid, row);
if (rowContainer != null)
{
DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
if (presenter == null)
{
dataGrid.ScrollIntoView(rowContainer, dataGrid.Columns[column]);
presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
}
DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
return cell;
}
return null;
}
6、从DataGrid获得Row
public static DataGridRow GetRow(DataGrid dataGrid, int index)
{
DataGridRow row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(index);
if (row == null)
{
dataGrid.UpdateLayout();
dataGrid.ScrollIntoView(dataGrid.Items[index]);
row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(index);
}
return row;
}
7、获取指定索引项的元素
public static TContainer GetContainerFromIndex<TContainer>
(ItemsControl itemsControl, int index)
where TContainer : DependencyObject
{
return (TContainer)
itemsControl.ItemContainerGenerator.ContainerFromIndex(index);
}
8、从DataGrid中获取正在编辑的Row
public static DataGridRow GetEditingRow(DataGrid dataGrid)
{
var sIndex = dataGrid.SelectedIndex;
if (sIndex >= 0)
{
var selected = GetContainerFromIndex<DataGridRow>(dataGrid, sIndex);
if (selected.IsEditing) return selected;
}
for (int i = 0; i < dataGrid.Items.Count; i++)
{
if (i == sIndex) continue;
var item = GetContainerFromIndex<DataGridRow>(dataGrid, i);
if (item.IsEditing) return item;
}
return null;
}
