reporting-servicesssrs-2008-r2ssrs-2012ssrs-tablixmsbi

How to handle "Select All" option in drop-down for multiple selection value in SSRS

I am facing an issue in SSRS. There is a drop-down parameter of multiple select value. By default it gives "(Select All)" option. If user choose this 'Select All' value then I want to show a label "--All--" on a text box . But I am not able catch this (Select All) option in the expression of text box. Generally we can handle other values in this way.. =Parameters!BranchName.Label(n)

Kindly suggest me any idea to catch this "Select All" option in expression

Solution
    1. Create a dataset which same with your dropdown binding value, but select count(*).
    2. And use below expression.

    =IIF(Parameters!ReportParameter1.Count = 4 , "Selected All","Not All")