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;
        }