Question

Here is the code I’m using
It’s supposed to create labels for each module name entered by a user and all the assessment names for that module under it. Should work with any number of modules and assessments. The problem is that it only shows assessments for the last module displayed.

dat.Modules and dat.Assessments are arraylists, each of them holds 4 elements with info about a module or an assessments, that is why i divide the count by 4.

private void testingButton_Click(object sender, EventArgs e)
{

        int pos1 = 50;
        int pos2 = 150;

        int modLength = dat.Modules.Count;
        modLength = modLength / 4;
        int assessLength = 0;
        int arrayData = 0;
        int displayCount = 0;

        for (int i = 0; i < modLength; i++)
        {

            this.moduleLabels.Add(new Label());
            System.Drawing.Point pLabel1 = new System.Drawing.Point(50, pos1);
            (moduleLabels[i] as Label).Location = pLabel1;
            (moduleLabels[i] as Label).Size = new System.Drawing.Size(100, 13);
            (moduleLabels[i] as Label).Text = dat.Modules[arrayData].ToString();
            tabPage5.Controls.Add((moduleLabels[i] as Label));
            String asd = dat.Modules[arrayData + 2].ToString();
            Console.WriteLine(asd);
            assessLength = int.Parse(asd);
            pos2 = pos1 + 25;
            for (int y = 0; y < assessLength; y++)
            {
                this.assessLabels.Add(new Label());
                System.Drawing.Point pLabel2 = new System.Drawing.Point(70, pos2);
                (assessLabels[y] as Label).Location = pLabel2;
                (assessLabels[y] as Label).Size = new System.Drawing.Size(250, 13);
                (assessLabels[y] as Label).Text = dat.Assessments[displayCount + 1].ToString() + " weights " + dat.Assessments[displayCount+2].ToString() +"%, Enter your mark:";

                textboxComputer.Add(new TextBox());
                System.Drawing.Point pText1 = new System.Drawing.Point(400, pos2);
                (textboxComputer[y] as TextBox).Location = pText1;
                (textboxComputer[y] as TextBox).Size = new System.Drawing.Size(20, 20);


                tabPage5.Controls.Add(assessLabels[y] as Label);
                tabPage5.Controls.Add(textboxComputer[y] as TextBox);
                pos2 = pos2 + 25;
                displayCount = displayCount + 4;
            }

            pos1 = pos2+25;
            arrayData = arrayData + 4;

        }
    }

this is an example of what it displays

http://dc540.4shared.com/download/YI8IENYI/tsid20120501-211723-cbc785f9/asd.jpg

The first two modules should have their assessments listed. The first one doesn’t display any. For Java it only displays the last one, out of 3 total for that module. And for the last Module “Another Module” it displays all assessments.

Answer 1

For each increment of i, y starts at 0. You then add new labels to assessLabels, but attempt to access the one you added by using assessLabels[y] which would usually yield the labels created for the previous value of i. This causes labels created for the first module to be reused by the next, and so forth.

A quick solution is not to use assessLabels[y] but assessLabels[assessLabels.Count - 1].

A better solution is to create a local variable for the labels, set their properties, and then add them to the list:

for (int y = 0; y < assessLength; y++)
{
    Label assessLabel = new Label();
    assessLabel.Location = ...;
    // etc.
    tabPage5.Controls.Add(assessLabel);
    assessLabels.Add(assessLabel);
}

This would also remove the need to continuously cast the ArrayList members and unneeded access to the list.

PS. If assessLabels only contains objects of type Labels, consider using a List<Label> instead.