wpf數據驗證實例及常用方法小結

雖然標題是wpf數據驗證，但並不是對IDataErrorInfo、ValidationRule、屬性中throw Exception這幾種驗證方式的介紹；

之前做項目時(例如員工工資管理)，根據員工編號和年度月份驗證 當月數據的唯一性，因為第一次開發wpf經驗不足，所以用過幾種不同的方式，並且現在用的這種方式也不是很滿意，如果哪位大神有更好的辦法 麻煩發個鏈接。

文章最后會把驗證、列表的樣式和驗證中常使用的一些方法貼出來，方便大家使用；

列表頁面 員工編號和年度月份驗證

添加修改頁面 填寫編號選擇月份后，驗證不通過都是在編號處提示

 

一、言歸正傳，逐步寫一下我當時的思路

1、為了實現這種需求的驗證，最先想到的就是實現了ValidationRule的自定義驗證類(ValidateExistLogName)能有一個屬性(ValiByProperty) binding上月份中選擇的值，關聯月份和當前輸入的員工編號來驗證當月是否存在；

<Binding.ValidationRules>

<tool:ValidateExistLogName ValiByProperty="{Binding CurMonth}"/>

</Binding.ValidationRules>

　　但是只有DependencyObject派生類的DependencyProperty屬性才能進行binding，於是我找到了給ValidationRule派生類的屬性上binding的辦法

參考鏈接：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

　　這種方式可能添加頁面比較好實現，但是對於列表DataGrid恐怕binding起來就，也許有人說可以DataGrid的IsReadOnly=false，但是我的需求是修改頁面修改的同時支持列表直接修改。

 

2、對實體類添加PropertyChangedEventHandler事件，這種方式可以實現，但是卻不是在ValidationRule中驗證，而且事件中的邏輯代碼也稍較麻煩，因為e.PropertyName綁定的是datepicker控件時，需throw new Exception才能顯示出來錯誤

列表中 初始化列表時遍歷datagrid中的綁定源數據：
 foreach (var item in data)
            {
                //為新加數據也加入事件
                item.PropertyChanged -= new System.ComponentModel.PropertyChangedEventHandler(source_PropertyChanged);
                item.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(source_PropertyChanged);
            }

添加或者修改直接給綁定的實體類添加事件：
source.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(source_PropertyChanged);

 

3、期間還嘗試了別的，但改動不大 基本記不清楚了，最后還是在派生自ValidationRule的類中添加需要驗證的實體屬性

public class ValidateExistCurMonthOrLogName : ValidationRule
{
    public object Entity { get; set; }
    public int ValiPropertyType { get; set; }//1驗證LogName，2驗證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, "不能為空！");
                }
                else if (!int.TryParse(value as string, out tmp))
                {
                    return new ValidationResult(false, "請輸入正確的數字！");
                }
                else if(...驗證是否已存在)
　　　　　　　　　.........
　　　　　　}
                .........

    }  
}


1、DataGrid列表
//在單元格開始編輯的時候，把要驗證的實體賦值
dataGrid.PreparingCellForEdit += delegate(object sender, DataGridPreparingCellForEditEventArgs e)
{
              //記錄原始狀態
                AllowanceData model = e.Row.Item as AllowanceData;
                allowanceDataHelper.SourceToModel(model, originalModel);
                //獲取cell
                DataGridCell cell = OperateControlHelper.GetCell(dataGrid, e.Row.GetIndex(), e.Column.DisplayIndex);
                //判斷當前編輯的是TextBox還是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、添加或修改頁面直接調用
InitValidateExistCurMonthOrLogName(txbLogName, new ValidateExistCurMonthOrLogName() { Entity = source });
InitValidateExistCurMonthOrLogName(dpCurMonth, new ValidateExistCurMonthOrLogName() { Entity = source });

//調用
void InitValidateExistCurMonthOrLogName(FrameworkElement node, ValidateExistCurMonthOrLogName modelArgs)
        {
            //獲取類型
            DependencyProperty depenPro;
            if (node is DatePicker)
            {
                depenPro = DatePicker.TextProperty;
            }
            else
            {
                depenPro = TextBox.TextProperty;
            }
            //獲取自定義驗證
            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、列表的樣式

<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驗證中常用的方法

1、獲取自定義驗證類

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、遞歸判斷是否有未通過驗證的控件

        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、向控件中添加錯誤驗證

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 = "該用戶在本月已存在數據！";

            Validation.MarkInvalid(
                fe.GetBindingExpression(dp),
                validationError);
        }

4、清空控件中的錯誤驗證

public static void ClearValidationError(FrameworkElement fe, DependencyProperty dp)
        {
            Validation.ClearInvalid(fe.GetBindingExpression(dp));
        }

5、從DataGrid獲得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、從DataGrid獲得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、獲取指定索引項的元素

public static TContainer GetContainerFromIndex<TContainer>
  (ItemsControl itemsControl, int index)
    where TContainer : DependencyObject
        {
            return (TContainer)
              itemsControl.ItemContainerGenerator.ContainerFromIndex(index);
        }

8、從DataGrid中獲取正在編輯的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;
        }