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C# Expression類代碼示例

本文整理匯總了C#中System.Linq.Expressions.Expression的典型用法代碼示例。如果您正苦於以下問題:C# Expression類的具體用法?C# Expression怎麽用?C# Expression使用的例子?那麽, 這裏精選的類代碼示例或許可以為您提供幫助。


Expression類屬於System.Linq.Expressions命名空間,在下文中一共展示了Expression類的1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C#代碼示例。

示例1: typeof

// Add the following directive to your file:
// using System.Linq.Expressions;  

// The block expression allows for executing several expressions sequentually.
// When the block expression is executed,
// it returns the value of the last expression in the sequence.
BlockExpression blockExpr = Expression.Block(
    Expression.Call(
        null,
        typeof(Console).GetMethod("Write", new Type[] { typeof(String) }),
        Expression.Constant("Hello ")
       ),
    Expression.Call(
        null,
        typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
        Expression.Constant("World!")
        ),
    Expression.Constant(42)
);

Console.WriteLine("The result of executing the expression tree:");
// The following statement first creates an expression tree,
// then compiles it, and then executes it.           
var result = Expression.Lambda<Func<int>>(blockExpr).Compile()();

// Print out the expressions from the block expression.
Console.WriteLine("The expressions from the block expression:");
foreach (var expr in blockExpr.Expressions)
    Console.WriteLine(expr.ToString());

// Print out the result of the tree execution.
Console.WriteLine("The return value of the block expression:");
Console.WriteLine(result);
開發者ID:.NET開發者,項目名稱:System.Linq.Expressions,代碼行數:33,代碼來源:Expression

輸出:

The result of executing the expression tree:
Hello World!

The expressions from the block expression:
Write("Hello ")
WriteLine("World!")
42

The return value of the block expression:
42


注:本文中的System.Linq.Expressions.Expression類示例由純淨天空整理自Github/MSDocs等開源代碼及文檔管理平台,相關代碼片段篩選自各路編程大神貢獻的開源項目,源碼版權歸原作者所有,傳播和使用請參考對應項目的License;未經允許,請勿轉載。