Expression.Assign Method
.NET Framework 4.5
Creates a BinaryExpression that represents an assignment operation.
Namespace: System.Linq.Expressions
Assembly: System.Core (in System.Core.dll)
Parameters
- left
- Type: System.Linq.Expressions.Expression
An Expression to set the Left property equal to.
- right
- Type: System.Linq.Expressions.Expression
An Expression to set the Right property equal to.
Return Value
Type: System.Linq.Expressions.BinaryExpressionA BinaryExpression that has the NodeType property equal to Assign and the Left and Right properties set to the specified values.
The following code example shows how to create an expression that represents an assignment operation.
// Add the following directive to your file:
// using System.Linq.Expressions;
// To demonstrate the assignment operation, we create a variable.
ParameterExpression variableExpr = Expression.Variable(typeof(String), "sampleVar");
// This expression represents the assignment of a value
// to a variable expression.
// It copies a value for value types, and
// copies a reference for reference types.
Expression assignExpr = Expression.Assign(
variableExpr,
Expression.Constant("Hello World!")
);
// The block expression allows for executing several expressions sequentually.
// In this block, we pass the variable expression as a parameter,
// and then assign this parameter a value in the assign expression.
Expression blockExpr = Expression.Block(
new ParameterExpression[] { variableExpr },
assignExpr
);
// Print out the assign expression.
Console.WriteLine(assignExpr.ToString());
// The following statement first creates an expression tree,
// then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda<Func<String>>(blockExpr).Compile()());
// This code example produces the following output:
//
// (sampleVar = "Hello World!")
// Hello World!
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
