How can i declare variables inside LINQ method

Question

How can i declare variables in below method

For example:

double price = double.Parse(((TextBox)r.FindControl("txtUnitprice")).Text);

double total = GvProducts.Rows
                         .Cast<GridViewRow>()
                         .Where(r => ((CheckBox)r.FindControl("chkSel")).Checked)
                         .Sum(r => 
                              double.Parse(((TextBox)r.FindControl("txtQuantity")).Text) * 
                              double.Parse(((TextBox)r.FindControl("txtUnitprice")).Text));

With query syntax you can use the `let` keyword, in method syntax you could use an anonymous type. — Tim Schmelter, Jan 14 '16 at 12:46
`r => { double price = double.Parse(((TextBox)r.FindControl("txtUnitprice")).Text); /* do something with price */; return price; }`. Note that if you are passing an Expression (I believe in this case you are *not*), then you are unable to write an expression block (and thus cannot define a variable inside the expression) — Rob, Jan 14 '16 at 12:46

score 1 · Answer 1 · answered Jan 14 '16 at 12:52

When any method expects a Func you have two possibilites (or to be exact three).

Add a single-line-expression (as already done)
Add the name of a delegate:

Sum(x => MyMethod(x)) Where MyMethod is a method within your class returning an int and expecting a T).
Add a multi-line expression embraced in curly brackets:

Sum(x => { /* any statements */ })

How can i declare variables inside LINQ method

1 Answers1