hi sandeep,
Variants are used to save the data and retrieve the same when required. This is an option used in ALV.
SAP provides standard interfaces for initializing and retrieving the display variant information. This includes three function modules and four subroutines.
1. REUSE_ALV_VARIANT_DEFAULT_GET.
This FM is used to get the default variant for the report if it has been set.
EXPORTING
I_SAVE : Controls the storage mode. Allowed values are :
‘A‘ : Standard and user specific variants
‘U’ : User specific variants
‘X’ : Standard Variants
CHANGING
CS_VARIANT : Gets the default variant in a structure like DISVARIANT.
2. REUSE_ALV_VARIANT_F4
This FM is used to get the possible values of the variants on the selection screen.
EXPORTING
IS_VARIANT : Structure of this parameter is like DISVARIANT. Pass the program name through this.
I_SAVE : Controls type of variant to be displayed in value help. Allowed values are
‘A‘ Standard and user specific variants
‘U’ User specific variants
‘X’ Standard Variants
IMPORTING
E_EXIT : If this parameter is blank then user has selected some variant.
ES_VARIANT :
Selected variant is populated in this work area. It’s of structure like DISVARIANT.
3.REUSE_ALV_VARIANT_EXISTENCE
This FM is used to check existence of a
display variant.
EXPORTING
I_SAVE : Type of variant. Allowed values are
‘A‘ Standard and user specific variants
‘U’ User specific variants
‘X’ Standard Variants
CHANGING
CS_VARIANT : Pass on variant details. The structure of this field is like DISVARIANT.
 DATA AREAS TO BE DECLARED FOR VARIANTS :
Data, which will be, used by the standard function modules in ALV for variants. A sample data deceleration is as mentioned below.
DATA: WS_X_VARIANT LIKE DISVARIANT,
WS_VARIANT LIKE DISVARIANT,
WS_SAVE TYPE C,
WS_EXIT TYPE C,
WS_REPID LIKE SY-REPID.
REUSE_ALV_VARIANT_DEFAULT_GET
____________________________________________________
Text
Read default layout (description only, w/o field catalog)
Functionality
Provides the default variant for the list specified in the structure
parameter CS_VARIANT of a program.
REUSE_ALV_VARIANT_F4
____________________________________________________
Text
Display variant selection dialog box
Functionality
Possible entries help, if the variant is defined explicitly as an input
field on a screen. The selection must be specified by at least partially
filling the parameter structure IS_VARIANT.
REUSE_ALV_VARIANT_EXISTENCE
____________________________________________________
Text
Checks whether a display variant exists
CS_VARIENTS holds the information about varients like:
ABAP Program Name
Mgt. ID for repeated calls from the same program
Logical group name
User name for user-specific storage
Layout
Description for layout
Dependent variant entry vector
Functionality
This function module checks the existence in the database of a display
variant passed in the interface.
check this example in the below link
http://www.sap-img.com/abap/use-simple-alv-functions-to-make-reporting-easy.htm
**if useful don't forget to reward with points...**
Bluesky
