本文整理汇总了C#中Type.IsNullable方法的典型用法代码示例。如果您正苦于以下问题：C# Type.IsNullable方法的具体用法？C# Type.IsNullable怎么用？C# Type.IsNullable使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Type的用法示例。
在下文中一共展示了Type.IsNullable方法的10个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: GetDefaultMappingFromEnumType
public static Type GetDefaultMappingFromEnumType(MappingSchema mappingSchema, Type enumType)
{
var type = enumType.ToNullableUnderlying();
if (!type.IsEnumEx())
return null;
var fields =
(
from f in type.GetFieldsEx()
where (f.Attributes & EnumField) == EnumField
let attrs = mappingSchema.GetAttributes<MapValueAttribute>(f, a => a.Configuration)
select
(
from a in attrs
where a.Configuration == attrs[0].Configuration
orderby !a.IsDefault
select a
).ToList()
).ToList();
Type defaultType = null;
if (fields.All(attrs => attrs.Count != 0))
{
var attr = fields.FirstOrDefault(attrs => attrs[0].Value != null);
if (attr != null)
{
var valueType = attr[0].Value.GetType();
if (fields.All(attrs => attrs[0].Value == null || attrs[0].Value.GetType() == valueType))
defaultType = valueType;
}
}
if (defaultType == null)
defaultType = Enum.GetUnderlyingType(type);
if (enumType.IsNullable() && !defaultType.IsClassEx() && !defaultType.IsNullable())
defaultType = typeof(Nullable<>).MakeGenericType(defaultType);
return defaultType;
}示例2: GetConverter
public static Tuple<LambdaExpression, LambdaExpression, bool> GetConverter(MappingSchema mappingSchema, Type from, Type to)
{
if (mappingSchema == null)
mappingSchema = MappingSchema.Default;
var p = Expression.Parameter(from, "p");
var ne = null as LambdaExpression;
if (from == to)
return Tuple.Create(Expression.Lambda(p, p), ne, false);
if (to == typeof(object))
return Tuple.Create(Expression.Lambda(Expression.Convert(p, typeof(object)), p), ne, false);
var ex =
GetConverter (mappingSchema, p, @from, to) ??
ConvertUnderlying(mappingSchema, p, @from, @from.ToNullableUnderlying(), to, to.ToNullableUnderlying()) ??
ConvertUnderlying(mappingSchema, p, @from, @from.ToUnderlying(), to, to.ToUnderlying());
if (ex != null)
{
ne = Expression.Lambda(ex.Item1, p);
if (from.IsNullable())
ex = Tuple.Create(
Expression.Condition(Expression.PropertyOrField(p, "HasValue"), ex.Item1, new DefaultValueExpression(mappingSchema, to)) as Expression,
ex.Item2);
else if (from.IsClassEx())
ex = Tuple.Create(
Expression.Condition(Expression.NotEqual(p, Expression.Constant(null, from)), ex.Item1, new DefaultValueExpression(mappingSchema, to)) as Expression,
ex.Item2);
}
if (ex != null)
return Tuple.Create(Expression.Lambda(ex.Item1, p), ne, ex.Item2);
if (to.IsNullable())
{
var uto = to.ToNullableUnderlying();
var defex = Expression.Call(_defaultConverter,
Expression.Convert(p, typeof(object)),
Expression.Constant(uto)) as Expression;
if (defex.Type != uto)
defex = Expression.Convert(defex, uto);
defex = GetCtor(uto, to, defex);
return Tuple.Create(Expression.Lambda(defex, p), ne, false);
}
else
{
var defex = Expression.Call(_defaultConverter,
Expression.Convert(p, typeof(object)),
Expression.Constant(to)) as Expression;
if (defex.Type != to)
defex = Expression.Convert(defex, to);
return Tuple.Create(Expression.Lambda(defex, p), ne, false);
}
}示例3: GetToString
static Expression GetToString(Type from, Type to, Expression p)
{
if (to == typeof(string) && !from.IsNullable())
{
var mi = from.GetMethodEx("ToString", new Type[0]);
return mi != null ? Expression.Call(p, mi) : null;
}
return null;
}示例4: ConvertTo
internal static object ConvertTo(string valueString, Type type)
{
if (valueString == null)
{
return null;
}
if (type.IsNullable() && String.Equals(valueString, "null", StringComparison.Ordinal))
{
return null;
}
// TODO 1668: ODL beta1's ODataUriUtils.ConvertFromUriLiteral does not support converting uri literal
// to ODataEnumValue, but beta1's ODataUriUtils.ConvertToUriLiteral supports converting ODataEnumValue
// to uri literal.
if (TypeHelper.IsEnum(type))
{
string[] values = valueString.Split(new[] { '\'' }, StringSplitOptions.None);
if (values.Length == 3 && String.IsNullOrEmpty(values[2]))
{
// Remove the type name if the enum value is a fully qualified literal.
valueString = values[1];
}
Type enumType = TypeHelper.GetUnderlyingTypeOrSelf(type);
object[] parameters = new[] { valueString, Enum.ToObject(enumType, 0) };
bool isSuccessful = (bool)EnumTryParseMethod.MakeGenericMethod(enumType).Invoke(null, parameters);
if (!isSuccessful)
{
throw Error.InvalidOperation(SRResources.ModelBinderUtil_ValueCannotBeEnum, valueString, type.Name);
}
return parameters[1];
}
// The logic of "public static object ConvertFromUriLiteral(string value, ODataVersion version);" treats
// the date value string (for example: 2015-01-02) as DateTimeOffset literal, and return a DateTimeOffset
// object. However, the logic of
// "object ConvertFromUriLiteral(string value, ODataVersion version, IEdmModel model, IEdmTypeReference typeReference);"
// can return the correct Date object.
if (type == typeof(Date) || type == typeof(Date?))
{
EdmCoreModel model = EdmCoreModel.Instance;
IEdmPrimitiveTypeReference dateTypeReference = EdmLibHelpers.GetEdmPrimitiveTypeReferenceOrNull(type);
return ODataUriUtils.ConvertFromUriLiteral(valueString, ODataVersion.V4, model, dateTypeReference);
}
object value = ODataUriUtils.ConvertFromUriLiteral(valueString, ODataVersion.V4);
bool isNonStandardEdmPrimitive;
EdmLibHelpers.IsNonstandardEdmPrimitive(type, out isNonStandardEdmPrimitive);
if (isNonStandardEdmPrimitive)
{
return EdmPrimitiveHelpers.ConvertPrimitiveValue(value, type);
}
else
{
type = Nullable.GetUnderlyingType(type) ?? type;
return Convert.ChangeType(value, type, CultureInfo.InvariantCulture);
}
}示例5: ConvertParameterType
public override Type ConvertParameterType(Type type, DataType dataType)
{
if (type.IsNullable())
type = type.ToUnderlying();
switch (dataType)
{
case DataType.Boolean: if (type == typeof(bool)) return typeof(byte); break;
case DataType.Guid : if (type == typeof(Guid)) return typeof(string); break;
}
return base.ConvertParameterType(type, dataType);
}示例6: CanCreateEdmModel_WithDateAndTimeOfDay_AsActionParameter
public void CanCreateEdmModel_WithDateAndTimeOfDay_AsActionParameter(Type paramType, string expect)
{
// Arrange
ODataModelBuilder builder = ODataModelBuilderMocks.GetModelBuilderMock<ODataModelBuilder>();
EntityTypeConfiguration<Movie> movie = builder.EntitySet<Movie>("Movies").EntityType;
var actionBuilder = movie.Action("ActionName");
actionBuilder.Parameter(paramType, "p1");
MethodInfo method = typeof(ProcedureConfiguration).GetMethod("CollectionParameter", BindingFlags.Instance | BindingFlags.Public);
method.MakeGenericMethod(paramType).Invoke(actionBuilder, new[] { "p2" });
// Act
IEdmModel model = builder.GetEdmModel();
//Assert
IEdmOperation action = Assert.Single(model.SchemaElements.OfType<IEdmAction>());
Assert.Equal("ActionName", action.Name);
IEdmOperationParameter parameter = action.FindParameter("p1");
Assert.Equal(expect, parameter.Type.FullName());
Assert.Equal(paramType.IsNullable(), parameter.Type.IsNullable);
parameter = action.FindParameter("p2");
Assert.Equal("Collection(" + expect + ")", parameter.Type.FullName());
Assert.Equal(paramType.IsNullable(), parameter.Type.IsNullable);
}示例7: ConvertTo
internal static object ConvertTo(string valueString, Type type)
{
if (valueString == null)
{
return null;
}
// TODO 1668: ODL beta1's ODataUriUtils.ConvertFromUriLiteral does not support converting uri literal
// to ODataEnumValue, but beta1's ODataUriUtils.ConvertToUriLiteral supports converting ODataEnumValue
// to uri literal.
if (TypeHelper.IsEnum(type))
{
string[] values = valueString.Split(new[] { '\'' }, StringSplitOptions.None);
if (values.Length == 3 && String.IsNullOrEmpty(values[2]))
{
// Remove the type name if the enum value is a fully qualified literal.
valueString = values[1];
}
if (type.IsNullable() && String.Equals(valueString, "null", StringComparison.Ordinal))
{
return null;
}
Type enumType = TypeHelper.GetUnderlyingTypeOrSelf(type);
object[] parameters = new[] { valueString, Enum.ToObject(enumType, 0) };
bool isSuccessful = (bool)enumTryParseMethod.MakeGenericMethod(enumType).Invoke(null, parameters);
if (!isSuccessful)
{
throw Error.InvalidOperation(SRResources.ModelBinderUtil_ValueCannotBeEnum, valueString, type.Name);
}
return parameters[1];
}
object value = ODataUriUtils.ConvertFromUriLiteral(valueString, ODataVersion.V4);
bool isNonStandardEdmPrimitive;
EdmLibHelpers.IsNonstandardEdmPrimitive(type, out isNonStandardEdmPrimitive);
if (isNonStandardEdmPrimitive)
{
return EdmPrimitiveHelpers.ConvertPrimitiveValue(value, type);
}
else
{
type = Nullable.GetUnderlyingType(type) ?? type;
return Convert.ChangeType(value, type, CultureInfo.InvariantCulture);
}
}示例8: NumericExpression
public NumericExpression(Type type)
: this()
{
IsNullable = type.IsNullable();
}示例9: GetToString
static Expression GetToString(Type from, Type to, Expression p)
{
if (to == typeof(string) && !from.IsNullable())
{
var mi = from.GetMethod("ToString", BindingFlags.Instance | BindingFlags.Public, null, new Type[0], null);
return mi != null ? Expression.Call(p, mi) : null;
}
return null;
}示例10: GenerateNullableMethodCall
// returns x=>x==null?null:f(x.Value) with cast to Nullable if needed
private Maybe<Expression> GenerateNullableMethodCall(Type type, Expression instance, int errorPos, string id, TokenId nextToken, Lazy<Expression[]> argumentList)
{
if (type.IsNullable())
{
var expression = TryParseMemberAcces(type.GetGenericArguments()[0], Expression.Property(instance, "Value"), nextToken, errorPos, id);
return expression.Select(e =>
{
return new
{
expression = e,
protectedExpression = !e.Type.IsNullable() && e.Type.IsValueType
? Expression.Convert(e, typeof (Nullable<>).MakeGenericType(e.Type))
: e
};
}).Select( notNull =>
{
var condition = (Expression)Expression.Condition(Expression.Equal(instance, Expression.Constant(null, type)),
Expression.Constant(null, notNull.protectedExpression.Type), notNull.protectedExpression);
// attach raw expression to condition to get it name in GetConditionalName()
ExtensionsProvider.SetValue(condition, notNull.expression);
return condition;
}
).ToMaybe();
}
return Maybe.Nothing;
}