cannot convert from "method group" to "string"

Question

sorry to bother you all. I'm programming a website and i'm trying to hash the password before storing it in the database but I get the error. I've seen related answers which advice people to use ".ToString()", however when I try this it seems to create more errors. Any help would be greatly appreciated.

 try
            {
                //hashing attempt
                string hashresult = Convert.ToInt32(FormsAuthentication.HashPasswordForStoringInConfigFile(TextBox4.Text.Trim, "SHA1")); //the error is on this line (TextBox4.Text.Trim)
                //.ToString()
                //end


                SqlConnection con = new SqlConnection(strcon);

                if (con.State == System.Data.ConnectionState.Closed)
                {
                    //if its closed the program will open it
                    con.Open();
                }
                //texbox info to SQL
                SqlCommand cmd = new SqlCommand("insert into user_master_tbl(name,email,dob,region,postcode,user_id,password) values(@name,@email,@dob,@region,@postcode,@user_id,@password)", con);
                //connecting textbox to the information typed in
                cmd.Parameters.AddWithValue("@name", TextBox3.Text.Trim());
                cmd.Parameters.AddWithValue("@email", TextBox1.Text.Trim());
                cmd.Parameters.AddWithValue("@dob", TextBox2.Text.Trim());
                cmd.Parameters.AddWithValue("@region", DropDownList1.SelectedItem.Value);
                cmd.Parameters.AddWithValue("@postcode", TextBox6.Text.Trim());
                cmd.Parameters.AddWithValue("@user_id", TextBox9.Text.Trim());
                cmd.Parameters.AddWithValue("@password", hashresult);
                //firing connection to database
                cmd.ExecuteNonQuery();
                con.Close();
                Response.Write("<script>" + "alert('Account created successfully, please proceed to login to your account');" + "</script>");
            }```

Answer 1

TextBox4.Text.Trim

...should be:

TextBox4.Text.Trim()

The whole line should look like this:

string hashresult = FormsAuthentication.HashPasswordForStoringInConfigFile(TextBox4.Text.Trim(), "SHA1");