本文整理匯總了VB.NET中System.Linq.Expressions.Expression.Switch方法的典型用法代碼示例。如果您正苦於以下問題：VB.NET Expression.Switch方法的具體用法？VB.NET Expression.Switch怎麽用？VB.NET Expression.Switch使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類System.Linq.Expressions.Expression的用法示例。
在下文中一共展示了Expression.Switch方法的2個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的VB.NET代碼示例。
示例1: SwitchCase
' Add the following directive to the file:
' Imports System.Linq.Expressions
' An expression that represents the switch value.
Dim switchValue As ConstantExpression = Expression.Constant(2)
' This expression represents a switch statement
' without a default case.
Dim switchExpr As SwitchExpression =
Expression.Switch(
switchValue,
New SwitchCase() {
Expression.SwitchCase(
Expression.Call(
Nothing,
GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
Expression.Constant("First")
),
Expression.Constant(1)
),
Expression.SwitchCase(
Expression.Call(
Nothing,
GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
Expression.Constant("Second")
),
Expression.Constant(2)
)
}
)
' The following statement first creates an expression tree,
' then compiles it, and then runs it.
Expression.Lambda(Of Action)(switchExpr).Compile()()輸出：
Second
示例2: GetType
' Add the following directive to the file:
' Imports System.Linq.Expressions
' An expression that represents the switch value.
Dim switchValue As ConstantExpression = Expression.Constant(3)
' This expression represents a switch statement
' that has a default case.
Dim switchExpr As SwitchExpression =
Expression.Switch(
switchValue,
Expression.Call(
Nothing,
GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
Expression.Constant("Default")
),
New SwitchCase() {
Expression.SwitchCase(
Expression.Call(
Nothing,
GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
Expression.Constant("First")
),
Expression.Constant(1)
),
Expression.SwitchCase(
Expression.Call(
Nothing,
GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
Expression.Constant("Second")
),
Expression.Constant(2)
)
}
)
' The following statement first creates an expression tree,
' then compiles it, and then runs it.
Expression.Lambda(Of Action)(switchExpr).Compile()()輸出：
Default