ParameterBuilder¶

Create parameter declarations for methods, constructors, and indexers.

See also: Emit Overview | MethodBuilder | ConstructorBuilder | IndexerBuilder

Factory Methods¶

Method	Description
`For(string name, string type)`	Create a parameter
`For<T>(string name, ValidSymbol<T> type)`	Create a parameter using a symbol's globally qualified name

Configuration¶

param.WithDefaultValue("0")
param.WithDefaultValue("\"default\"")
param.WithDefaultValue("null")
param.AsRef()
param.AsOut()
param.AsIn()
param.AsParams()
param.AsThis()  // for extension method target

Attributes¶

param.WithAttribute("CallerMemberName")
param.WithAttribute("NotNull")
param.WithAttribute("FromQuery", a => a.WithArgument("Name = \"id\""))
param.WithAttribute(preConfiguredAttribute)

Example¶

// Simple parameter
MethodBuilder.For("Process")
    .AddParameter("input", "string")
    .AddParameter("count", "int", p => p.WithDefaultValue("0"))

// Extension method
MethodBuilder.For("ToUpper")
    .AddParameter("value", "string", p => p.AsThis())

// Out parameter
MethodBuilder.For("TryParse")
    .AddParameter("input", "string")
    .AddParameter("result", "int", p => p.AsOut())

Properties¶

param.Name              // string
param.Type              // string
param.IsExtensionTarget // bool — true if 'this' modifier
param.Modifier          // ParameterModifier
param.DefaultValue      // string?

ParameterModifier Enum¶

Value	Description
`None`	No modifier
`Ref`	`ref` parameter
`Out`	`out` parameter
`In`	`in` parameter
`Params`	`params` parameter
`This`	`this` parameter (extension method target)

ParameterValidationKind Enum¶

Value	Description
`ThrowIfNull`	`ArgumentNullException` if null
`ThrowIfNullOrEmpty`	`ArgumentException` if null or empty
`ThrowIfNullOrWhiteSpace`	`ArgumentException` if null, empty, or whitespace
`ThrowIfOutOfRange`	`ArgumentOutOfRangeException` if outside specified range
`ThrowIfNotPositive`	`ArgumentOutOfRangeException` if zero or negative
`ThrowIfNegative`	`ArgumentOutOfRangeException` if negative
`ThrowIfZero`	`ArgumentOutOfRangeException` if zero