IfElseActivity

 

IfElseActivity

1.IfElseActivity有两个IfElseBranch子控件，分别作为IfElse的两个分支容器,系统自动添加，

2.其中左边(为真件条)的IfElseBranch容器要设Condition

3.IfElse左边(为真件条)的IfElseBranch容器的Condition有两个条件模式:Code Condition,Declarative Rule Condition

 

Code Condition模式

Code Condition模式，由对e.Result赋不同值决定执行不同的分支

要使用该模式，会在代码中用到CodeCondition对象与CodeCondition对象的Condition事件

    'Code Condition模式的判断，由对e.Result赋不同值决定执行不同的分支
 Private Sub ifElse_a_Condition()Sub ifElse_a_Condition(ByVal sender As System.Object, ByVal e As System.Workflow.Activities.ConditionalEventArgs)
        'e.Result如果为真，就执行左边(为真件条)的IfElseBranch容器
        'e.Result如果为假，就执行右边(为假件条)的IfElseBranch容器
        If temp = "456" Then
            e.Result = True
        Else
            e.Result = False
        End If
    End Sub

双击无法进入代码，可手写该过程，

从下拉框绑定时如报错，可在Workflow1.designer.vb中的手写绑定代码

'Workflow1.designer.vb中的绑定代码
Dim codecondition1 As System.Workflow.Activities.CodeCondition = New System.Workflow.Activities.CodeCondition
AddHandler codecondition1.Condition, AddressOf Me.ifElse_a_Condition
Me.ifElseBranchActivity1.Condition = codecondition1

 

Declarative Rule Condition模式

Declarative Rule Condition模式：由指定的表达式的值是否符合条件定执行不同的分支

代码实现

Workflow1.rules

<RuleDefinitions xmlns="http://schemas.microsoft.com/winfx/2006/xaml/workflow">

     <RuleDefinitions.Conditions>

         <RuleExpressionCondition Name="Condition1">

              <RuleExpressionCondition.Expression>

                   <ns0:CodeBinaryOperatorExpression Operator="ValueEquality" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">

                       <ns0:CodeBinaryOperatorExpression.Left>

                            <ns0:CodeFieldReferenceExpression FieldName="temp">

                                 <ns0:CodeFieldReferenceExpression.TargetObject>

                                     <ns0:CodeThisReferenceExpression />

                                 </ns0:CodeFieldReferenceExpression.TargetObject>

                            </ns0:CodeFieldReferenceExpression>

                       </ns0:CodeBinaryOperatorExpression.Left>

                       <ns0:CodeBinaryOperatorExpression.Right>

                            <ns0:CodePrimitiveExpression>

                                 <ns0:CodePrimitiveExpression.Value>

                                     <ns1:String xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">123</ns1:String>

                                 </ns0:CodePrimitiveExpression.Value>

                            </ns0:CodePrimitiveExpression>

                       </ns0:CodeBinaryOperatorExpression.Right>

                   </ns0:CodeBinaryOperatorExpression>

              </RuleExpressionCondition.Expression>

         </RuleExpressionCondition>

     </RuleDefinitions.Conditions>

</RuleDefinitions>

 

 

 Dim ruleconditionreference1 As Workflow.Activities.Rules.RuleConditionReference = New .RuleConditionReference

 ruleconditionreference1.ConditionName = "Condition1"

 Me.ifElseBranchActivity3.Condition = ruleconditionreference1