如果选中了所有CheckBoxList项，如何显示或隐藏按钮？

Question

i have this code .I want to make this like , when i checked all items , a button shows up .

        string connStr = "myconnstring" ;
        SqlCommand com;
        SqlConnection con = new SqlConnection(connStr);
        string s1 = string.Empty;
        foreach (ListItem item in this.CheckBoxList1.Items)
        {
            if (item.Selected)
            {
                s1 = item.ToString();
                com = new SqlCommand("Insert into tblml values('" + s1 + "')", con);
                con.Open();
                com.ExecuteNonQuery();
                con.Close();
            }
        }
        Response.Write("Inserted Successfully");

Any help appriciate.

Thanks

Answer 1

You could determine if they are all checked like this:

var isAllChecked = this.CheckBoxList1.Items.OfType<ListItem>().All(l => l.Selected);

and then you could hide/show your button using that variable:

this.button.Visible = isAllChecked;

---

Another option would be to create a variable at the top of the loop you already have:

var isAllChecked = true;

and then inside the loop add an else to the if (item.Selected) :

    ...
}
else { isAllChecked = false; }