Reputation: 29
I have an array of textboxes in which they change dyanmically depending on what the user types in. Those textboxes contain a number which represents a score of an assignment. Those score are linked to a module object. So if the user has 3 modules; 2 assignments on the first and second module and 3 assignments on the third module; then in total there would be 7 textboxes created for the user to input all their assignment marks.
What I am trying to do is to create a keyup event handler in which it gets the number in typed in by the user, and then dynamically calls a method to display the average of the the module. This is what I have so far. The following method gets called whenever the user types in a character:
public void calculateLevel4Modules(int counter) {
//iterate through modules
//iterate through assignts in that module
//whilst iterating, check tb and set userscore
//after iterating, update overall label with regards to modulecounter
//int assignmentCounter = 0;
//Console.WriteLine("in If statement.. " + counter);
for (int moduleCounter = 0; moduleCounter < requiredLevelList().Count; moduleCounter++)
{
int totalNumberOfAssignmentsInCurrentModule = requiredLevelList().ElementAt(moduleCounter).Assignments.Count;
Console.WriteLine("total number of assignmetns: " + totalNumberOfAssignmentsInCurrentModule);
assignmentCounter = assignmentCounter + totalNumberOfAssignmentsInCurrentModule;
Console.WriteLine("assignment counter: " + totalNumberOfAssignmentsInCurrentModule);
if (counter < assignmentCounter)
{
Console.WriteLine("in If statement.. " + userMarksTBLvl4[moduleCounter].Text);
try
{
int userMark = int.Parse(userMarksTBLvl4[counter].Text);
requiredLevelList().ElementAt(moduleCounter).Assignments.ElementAt(counter).UsersScore = userMark;
double modAvg = requiredLevelList().ElementAt(moduleCounter).getModuleScoreOverall();
moduleOverallLvl4[moduleCounter].Text = modAvg.ToString();
break;
}
catch (FormatException) { break; }
}
else { }
}
it works fine if the user has one module but if the user has two or more, then I get an error in the following line:
requiredLevelList().ElementAt(moduleCounter).Assignments.ElementAt(counter).UsersScore = userMark;
I am getting an out of bounds exception. I know why; its because counter is basically the # of the textbox that was typed into but by me using counter, I am accessing something not within the assignments list. This is an example of when the problem occus:
The user has 2 modules. In each module there are 2 assignments thus 4 textboxes are been created with their index ranging from 0 - 3. If the user wants to type in their score of the first assignment on the second module, its basically trying to write to the third index in that element then it crashes since that module only consist of 2 assignments.
Upvotes: 0
Views: 94
Reputation: 21712
There are some strange things in your code that make it hard to answer. First, the code you posted doesn't compile, so we have no way to test it.
Several times you use code like:
requiredLevelList().ElementAt(moduleCounter)
I assume requiredLevelList
is a method that returns a list of things. There is no reason to assume requiredLevelList
returns the same list, or even lists with the same number of elements, each time you call it. Maybe it does in your particular case, but this is a dangerous thing to rely on. You should use a construct like:
foreach (var module in requiredLevelList())
{
int totalNumberOfAssignmentsInCurrentModule = module.Assignments.Count;
...
module.Assignments.ElementAt(counter).UsersScore = userMark;
...
}
Code like this:
Console.WriteLine("total number of assignmetns: " + totalNumberOfAssignmentsInCurrentModule);
is symptomatic of trying to debug something after it has crashed. That is extremely inefficient. Learn how to use a debugger; you will not become an effective programmer until you know how to do this.
requiredLevelList().ElementAt(moduleCounter).Assignments.ElementAt(counter).UsersScore = userMark;
You're probably getting an out-of-bounds exception here because counter
is outside the indexes of Assignments
. Since you never initialize or change counter
, I have no way to know what it is or should be. A debugger will tell you this, use one.
the # of the textbox that was typed into but by me using counter, I am accessing something not within the assignments list.
OK, if you're typing something “not within the assignments list” then you have to test for that and decide what to do. Perhaps something like:
if (counter >= 0 && counter < module.Assignments.Count)
module.Assignments.ElementAt(counter).UsersScore = userMark;
else
throw new Exception("I really have no idea what you want to do here.");
This also looks wrong:
moduleOverallLvl4[moduleCounter].Text = modAvg.ToString();
You never tell us what moduleOverallLvl4
is, but here you're assuming it has the same size as what is returned by requiredLevelList()
. Maybe they are in this particular case, but that is a dangerous assumption. If these values are related, moduleOverallLvl4
should be contained in whatever class implements requiredLevelList
, and you should have a method that assigns getModuleScoreOverall()
to the correct element of moduleOverallLvl4
.
Upvotes: 1