Struct Variant

Implementation of a Variant type with common arithmetic and logic operations. Variant is a container, not a class reference, that is when you assign a variant to another variant, you are copying content, just like you work with base types like int, char, string. The Variant type is a useful feature to implement an expression evaluator.

Implements

IConvertible

IComparable

Inherited Members

object.GetType()

object.Equals(object, object)

object.ReferenceEquals(object, object)

Namespace: Reportman.Reporting

Assembly: Reportman.Reporting.dll

Syntax

[JsonConverter(typeof(VariantJsonConverter))]
[JsonConverter(typeof(VariantSystemTextJsonConverter))]
public struct Variant : IConvertible, IComparable

Remarks

C# is a strongly typed language, this feature minimize runtime errors common when using implicit variable declaration (Visual Basic), or implicit type conversion (C or C++), however, at runtime, the requirements of an application can require the feature of operating with unknown/variable data types, usually this data comes from a database, and this data types can be unknown at compile time. Expression evaluation involving variable database fields is an example. Use only Variant type if your aplication requires this abstraction else it's better to use singular types.

Examples

Variant a=12;
Variant b=13;
Variant c=a+b;
Variant d="The result is:";
d=d+c.ToString();

Properties

AsDateTime

Property to get the variant value as a Datetime

Declaration

public DateTime AsDateTime { get; }

Property Value

Type	Description
DateTime

AsDecimal

Property to get the variant value as a decimal

Declaration

public decimal AsDecimal { get; }

Property Value

Type	Description
decimal

AsDouble

Property to get the variant value as a double

Declaration

public double AsDouble { get; }

Property Value

Type	Description
double

AsInteger

Property to get the variant value as an int

Declaration

public int AsInteger { get; }

Property Value

Type	Description
int

AsLong

Property to get the variant value as a long

Declaration

public long AsLong { get; }

Property Value

Type	Description
long

AsString

Property to get the variant value as a string

Declaration

public string AsString { get; }

Property Value

Type	Description
string

IsNull

Function to check if the current value is null.

Declaration

public bool IsNull { get; }

Property Value

Type	Description
bool	Returns true if the value is null (VariantType.Null).

VarType

Function to check the variant type.

Declaration

public VariantType VarType { get; }

Property Value

Type	Description
VariantType	Returns the VariantType for the current value. VariantType

Methods

Abs()

Returns the variant as a positive number, absolute value

Declaration

public Variant Abs()

Returns

Type	Description
Variant

AsObject()

Get the Variant as an object

Declaration

public object AsObject()

Returns

Type	Description
object

Remarks

For Null value the result is DBNull.Value. For binary data type, the result is a byte[] type

AssignFromObject(object)

Procedure to assign a Variant from any object type

Declaration

public void AssignFromObject(object obj)

Parameters

Type	Name	Description
object	obj

Remarks

If the object is a null reference, the result will be a Variant with type Null

CompareTo(Variant)

Compare to other Variant

Declaration

public int CompareTo(Variant obj)

Parameters

Type	Name	Description
Variant	obj

Returns

Type	Description
int

CompareTo(object)

Compare a Variant to an object

Declaration

public int CompareTo(object obj)

Parameters

Type	Name	Description
object	obj

Returns

Type	Description
int

Remarks

Returns 0 if both are equal, 1 if current instance is greater than object, else returns -1

Equals(object)

Compare a Variant with a object

Declaration

public override bool Equals(object obj)

Parameters

Type	Name	Description
object	obj

Returns

Type	Description
bool

Overrides

ValueType.Equals(object)

GetDbType()

Returns a DbType based on the Variant type

Declaration

public DbType GetDbType()

Returns

Type	Description
DbType

GetHashCode()

Necessary to override == operator

Declaration

public override int GetHashCode()

Returns

Type	Description
int

Overrides

ValueType.GetHashCode()

GetStream()

Gets the stream on a binary type Variant

Declaration

public MemoryStream GetStream()

Returns

Type	Description
MemoryStream

GetTypeCode()

Returns a TypeCode based on the Variant type

Declaration

public TypeCode GetTypeCode()

Returns

Type	Description
TypeCode

GetTypeString()

Function to get the type of the value as a string.

Declaration

public string GetTypeString()

Returns

Type	Description
string	Returns the string representation from the type of the value. Possible values are: VariantType.Null VariantType.Boolean VariantType.Byte VariantType.Char VariantType.Integer VariantType.Long VariantType.Decimal VariantType.Double VariantType.DateTime VariantType.Binary VariantType.String

IsBoolean()

Function to check if the current value is a boolean value.

Declaration

public bool IsBoolean()

Returns

Type	Description
bool	Returns true if the current value is a boolean value.

IsDateTime()

Function to check if the current value is a Datetime value.

Declaration

public bool IsDateTime()

Returns

Type	Description
bool	Returns true if the current value is a Datetime value.

IsInteger()

Function to check if the current value is an integer value.

Declaration

public bool IsInteger()

Returns

Type	Description
bool	Returns true if the current value is an ordinal, integer value. That is currently a Byte, Integer or Long type values.

IsNumber()

Function to check if the current value is a number.

Declaration

public bool IsNumber()

Returns

Type	Description
bool	Returns true if the current value is number. That is any integer, Double or Decimal value.

IsString()

Function to check if the current value is a string value.

Declaration

public bool IsString()

Returns

Type	Description
bool	Returns true if the current value is a string value.

SetStream(MemoryStream)

Assigns a memory stream to a Variant

Declaration

public void SetStream(MemoryStream memstream)

Parameters

Type	Name	Description
MemoryStream	memstream

ToBoolean(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public bool ToBoolean(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
bool

ToByte(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public byte ToByte(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
byte

ToChar(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public char ToChar(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
char

ToDateTime(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public DateTime ToDateTime(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
DateTime

ToDecimal(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public decimal ToDecimal(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
decimal

ToDouble(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public double ToDouble(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
double

ToInt16(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public short ToInt16(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
short

ToInt32(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public int ToInt32(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
int

ToInt64(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public long ToInt64(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
long

ToSByte(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public sbyte ToSByte(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
sbyte

ToSingle(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public float ToSingle(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
float

ToString()

Returns the value of a Variant as a string

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

ValueType.ToString()

ToString(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public string ToString(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
string

ToString(string, ParamType, bool)

Formats a Variant, with a display format

Declaration

public string ToString(string displayformat, ParamType paramtype, bool printnulls)

Parameters

Type	Name	Description
string	displayformat	The formatting string, depending on current value
ParamType	paramtype
bool	printnulls

Returns

Type	Description
string

ToType(Type, IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public object ToType(Type conversionType, IFormatProvider provider)

Parameters

Type	Name	Description
Type	conversionType
IFormatProvider	provider

Returns

Type	Description
object

ToUInt16(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public ushort ToUInt16(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
ushort

ToUInt32(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public uint ToUInt32(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
uint

ToUInt64(IFormatProvider)

Type transformation using a IFormatProvider

Declaration

public ulong ToUInt64(IFormatProvider provid)

Parameters

Type	Name	Description
IFormatProvider	provid

Returns

Type	Description
ulong

VariantFromObject(object)

This function creates a Variant from a object

Declaration

public static Variant VariantFromObject(object obj)

Parameters

Type	Name	Description
object	obj

Returns

Type	Description
Variant

Operators

operator +(Variant, Variant)

Binary add arithmetic operator

Declaration

public static Variant operator +(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
Variant

operator &(Variant, Variant)

Binary and logic operator

Declaration

public static Variant operator &(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
Variant

operator |(Variant, Variant)

Binary or logic operator

Declaration

public static bool operator |(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

operator /(Variant, Variant)

Binary division arithmetic operator

Declaration

public static Variant operator /(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
Variant

operator ==(Variant, Variant)

Compare two variants

Declaration

public static bool operator ==(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

Remarks

Two Variants containing null value are not equal

operator >(Variant, Variant)

Compare two Variants

Declaration

public static bool operator >(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

operator >=(Variant, Variant)

Compare two Variants

Declaration

public static bool operator >=(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

implicit operator bool(Variant)

Implicit conversion from Variant to bool

Declaration

public static implicit operator bool(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
bool

implicit operator byte(Variant)

Implicit conversion from Variant to byte

Declaration

public static implicit operator byte(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
byte

implicit operator char(Variant)

Implicit conversion from Variant to char

Declaration

public static implicit operator char(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
char

implicit operator DateTime(Variant)

Implicit conversion from Variant to DateTime

Declaration

public static implicit operator DateTime(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
DateTime

implicit operator decimal(Variant)

Implicit conversion from Variant to decimal

Declaration

public static implicit operator decimal(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
decimal

implicit operator double(Variant)

Implicit conversion from Variant to double

Declaration

public static implicit operator double(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
double

implicit operator short(Variant)

Implicit conversion from Variant to short

Declaration

public static implicit operator short(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
short

implicit operator int(Variant)

Implicit conversion from Variant to int

Declaration

public static implicit operator int(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
int

implicit operator long(Variant)

Implicit conversion from Variant to long

Declaration

public static implicit operator long(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
long

implicit operator string(Variant)

Implicit conversion from Variant to string

Declaration

public static implicit operator string(Variant avalue)

Parameters

Type	Name	Description
Variant	avalue

Returns

Type	Description
string

implicit operator Variant(bool)

Assigns a bool value to a Variant

Declaration

public static implicit operator Variant(bool avalue)

Parameters

Type	Name	Description
bool	avalue

Returns

Type	Description
Variant

implicit operator Variant(byte)

Assigns a byte value to a Variant

Declaration

public static implicit operator Variant(byte avalue)

Parameters

Type	Name	Description
byte	avalue

Returns

Type	Description
Variant

implicit operator Variant(char)

Assigns a char value to a Variant

Declaration

public static implicit operator Variant(char avalue)

Parameters

Type	Name	Description
char	avalue

Returns

Type	Description
Variant

implicit operator Variant(DateTime)

Assigns a DateTime value to a Variant

Declaration

public static implicit operator Variant(DateTime avalue)

Parameters

Type	Name	Description
DateTime	avalue

Returns

Type	Description
Variant

implicit operator Variant(decimal)

Assigns a decimal value to a Variant

Declaration

public static implicit operator Variant(decimal avalue)

Parameters

Type	Name	Description
decimal	avalue

Returns

Type	Description
Variant

implicit operator Variant(double)

Assigns a double value to a Variant

Declaration

public static implicit operator Variant(double avalue)

Parameters

Type	Name	Description
double	avalue

Returns

Type	Description
Variant

implicit operator Variant(int)

Assigns an int value to a Variant

Declaration

public static implicit operator Variant(int avalue)

Parameters

Type	Name	Description
int	avalue

Returns

Type	Description
Variant

implicit operator Variant(long)

Assigns a long value to a Variant

Declaration

public static implicit operator Variant(long avalue)

Parameters

Type	Name	Description
long	avalue

Returns

Type	Description
Variant

implicit operator Variant(string)

Assigns a string value to a Variant

Declaration

public static implicit operator Variant(string avalue)

Parameters

Type	Name	Description
string	avalue

Returns

Type	Description
Variant

operator !=(Variant, Variant)

Compare two Variants

Declaration

public static bool operator !=(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

operator <(Variant, Variant)

Compare two Variants

Declaration

public static bool operator <(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

operator <=(Variant, Variant)

Compare two Variants

Declaration

public static bool operator <=(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
bool

operator *(Variant, Variant)

Binary multiplier arithmetic operator

Declaration

public static Variant operator *(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
Variant

operator -(Variant, Variant)

Binary substraction arithmetic operator

Declaration

public static Variant operator -(Variant avalue1, Variant avalue2)

Parameters

Type	Name	Description
Variant	avalue1
Variant	avalue2

Returns

Type	Description
Variant

operator -(Variant)

Unary sign arithmetic operator

Declaration

public static Variant operator -(Variant avalue1)

Parameters

Type	Name	Description
Variant	avalue1

Returns

Type	Description
Variant

Implements

IConvertible

IComparable