使用未分配的局部变量

Question

I encountered an error. Despite declaring the variables (failturetext and userName) errors still appear. Can anyone please help me?

- Use of Unassigned local variable "FailureText" 
- Use of Unassigned local variable "UserName"


protected void Login1_LoginError(object sender, System.EventArgs e)
{
    TextBox FailureText;
    TextBox UserName; 

    //There was a problem logging in the user
    //See if this user exists in the database
    MembershipUser userInfo = Membership.GetUser(UserName.Text); // errors appear here
    if (userInfo == null)
    {
        //The user entered an invalid username...
        //error appear here ( failuretext.text) 
        FailureText.Text = "There is no user in the database with the username " + UserName.Text;  
    }

Thanks (:

Answer 1

You've declared the variables, but you haven't assigned anything to them before you are attempting to reference their properties. That's the origin of the messages. You've got bigger problems, though, because those represent UI controls and it's highly unlikely that they should be local variables in your function. They probably ought to belong to the page (or form) rather than be declared locally.

Answer 2

Regarding the compiler message - look at this link

 TextBox FailureText; - you declared a variable, but it is not initialized. you might set it to null / a value / default() - but you must initialize it
 TextBox UserName; - the same

when you call UserName.Text - the compiler alerts for the uninitialized UserName

Answer 3

If you wish to keep the same convention as you have at the moment, then to solve the issue of it failing compilation you want to assign the two variables a null value first before you try to reference them.

Like so:

TextBox FailureText = null;
TextBox UserName = null;

If you do this, you might need to check on whether they are still null when you try and assign the properties of these objects.

As people above have stated, you should not be doing it this way as UI controls should always be global to the form itself.