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C# Using ArrayList.IndexOf with multiple identical items

I've got a situation where I'm using an ArrayList to store a list of file names (full file path). When I add multiple items of the same file to the array, then use ArrayList.IndexOf to find the index (I'm reporting progress to a BackgroundWorker), it always returns the index of the first item since it's searching by the file name. This causes a problem with a progress bar, i.e. I'm processing 3 files, and when complete, the bar is only 1/3 full.
Here's some sample code (I'm simply adding items here, but in the real code they are added from a ListBox):
ArrayList list = new ArrayList();
list.Add("C:\Test\TestFile1.txt");
list.Add("C:\Test\TestFile1.txt");
list.Add("C:\Test\TestFile1.txt");
var files = list;
foreach (string file in files)
backgroundWorker1.ReportProgress(files.IndexOf(file) + 1);
When this runs, only 1 "percent" of progress is reported, since the IndexOf is finding the same file every time. Is there any way around this? Or does anyone have a suggestion on another way to get the index (or any unique identifier for each item)?

The simplest approach is just to use the index to iterate:
for (int i = 0; i < list.Count; i++)
{
backgroundWorks.ReportProgress(i + 1);
// Do stuff with list[i]
}

To achieve what you want, I would recomment using a for list. You won't have to search for any indexes and can report the progress easily to the backgroundWorker1:
for (int counter = 0; counter < files.Count; counter++)
{
backgroundWorker1.ReportProgress(counter + 1);
}
By doing this, you don't get problems with same filenames.
This would be the equivalent with foreach:
int counter = 1;
foreach (string file in files)
{
backgroundWorker1.ReportProgress(counter);
counter++;
}
But I think it's better to use for in this case.

You could make a copy of your list, and then remove each item from it as it is processed. Then you could return the percentage complete as a function of the count of the temp list divided by the count of the original list.
You could also just add to an int every time your background workers process a file and use that int to track the progress (percent complete should be the int divided by the number of files).
Of course with either approach you need to make sure you are modifying the variables in question in a thread-safe manner.

Try this and it works fine for me in case of reading files having so many lines of data.
int percentage = (int)((count / (double)lineCount) * 100.0);
backgroundWorker5.ReportProgress(percentage);
Here count is total count and linecount is present running count. By using thedse two,calculate the percentage. Keep this code in your for loop or while loop.

Assuming that progressbar max value is 100, and with one file processed out of three it should show 33(%) progress, you could count progress for each file processed and recalculate overall progress :
// list contains x file paths
var files = list;
double progressStep = 1 / files.Count;
for(int i = 0; i < files.Count; i++)
{
backgroundWorker1.ReportProgress((i + 1) * progressStep);
...
}
All that remained is to assign progress value in background worker to progress bar.

Increment through a list on a button list

I've stored a list of colors in my program. I am after an object in my scene to one of the colors in the list. So far, I have done the followings:
if(Input.GetKeyDown(KeyCode.O))
{
for(int i = 0; i < claddingColor.Count; i++)
{
claddingMaterial.color = claddingColor[i];
}
}
This isn't working due to a reason I know (and you can probably spot) but I lack to the verbal fortitude to write it down.
As opposed to have a multiple lines of the following:
claddingMaterial.color = claddingColor[0];
Each tied to different buttons, I like a way I can emulate the above but tie it to a single button press. Thus, if I hit the 0 button 5 times, it will loop through each color stored in the list. If I hit it for a sixth time, it will go back to the first color in the list.
Could someone please help me implement this? Or point me to something that I may learn how to do it for myself?

Define LastColor property as class member:
int LastColor;
In your function use modulo
if(Input.GetKeyDown(KeyCode.O))
{
claddingMaterial.color = claddingColor[(LastColor++) % claddingColor.Count];
}
Note: Depending on the type of claddingColor use Count for a List or Length for Array.

You won't need a for loop
int lastStep = 0;
if(Input.GetKeyDown(KeyCode.O))
{
claddingMaterial.color = claddingColor[lastStep++];
if (lastStep == claddingColor.Count)
lastStep = 0;
}

Looping and changing a list - remove doesn't always work

I'm trying to go through a loop 40 times and changing a list in the process.
This is the code:
for (int i = 0; i < 40; i++)
{
location = rand.Next(rows.Count);
rank = rand2.Next(pondRanks.Count);
ComputerPonds[rows[location]].Rank = (PondRank)pondRanks[rank];
rows.Remove(location);
pondRanks.Remove(rank);
}
For some reason the remove doesn't happen all the time, and only sometimes. Anyone has a suggestion?
Both of the list are List , they have 40 elements, and I want to remove the element itself.
Even when debugging I can see that the list count isn't the same (they both have the same initial numbers and they both need to do remove at this loop). If it matters, I'm working on windows phone platform..

I'm pretty sure you should be using List.RemoveAt not List.Remove. RemoveAt will remove the item at the specified index, whereas Remove will look for that object you passed in and remove it from the List if it's in there. But I'm pretty sure that looking at your code that location and rank represent the index, not the objects themselves.
for (int i = 0; i < 39; i++)
{
location = rand.Next(rows.Count);
rank = rand2.Next(pondRanks.Count);
ComputerPonds[location].Rank = (PondRank)pondRanks[rank];
rows.RemoveAt(location);
pondRanks.RemoveAt(rank);
}
EDIT: You may also want to consider making sure that your rows and pondRanks have enough elements (39) before starting the loop (or altering the i < 39 to max out at the upper limit of their length)

Programatically reference ascending variable names (var1, var2, ... )

I'm currently coding a project that can take up to 200 entries of a specific product, as determined by user input. Basically, my GUI loads, and I use jQuery to dynamically build the entries whenever there is a change to the amount field. When using jQuery, I simply give each of them ids in the form of variable1, variable2, ...., variableX (where X is the amount of entries indicated). Small snippet of code to clarify:
for(var i = 1;i <= amount_selected; i++) {
$('table_name tr:last').after('<tr><td><input type="text" id="variable' + i + '"></td></tr>');
}
Now when I try to move to the back end, I'm trying to reference these variable names by putting them in a list. I went ahead and put them in a list of HtmlInputText, to call the Variable names from the list itself. (This would save having to call all (up to 200) methods manually, which is really not an option).
So what I did (in C#) was:
List<HtmlInputText> listvar = new List<HtmlInputText>();
for(int i = 1; i <= amount_selected; i++) {
string j = "variable" + Convert.ToString(i);
HtmlInputText x = j;
listvar.Add((x));
samplemethod(listvar[i]);
}
But it's not working at all. Does anyone have any ideas as to how this would be done, without doing so manually? I know my logic might be completely off, but hopefully this illustrates at least what I'm attempting to do.

I'm assuming these inputs are in a form? If you're submitting then you can access the text boxes from the Request object:
List<string> results = new List<string>();
for (int i = 1; i <= amount_selected; i++)
{
string s = String.Format("{0}", Request.Form["variable" + Convert.ToString(i)]);
results.Add(s);
}

you could do $("#variable" + Convert.ToString(i)).val()

How to increment a number when something happens in a For loop

I'm using the following code to count the number of rows in an html table, store that number to use in a for loop which extracts text out of a <td> in each row.
Table myTable = browser.Div(Find.ById("resultSpan")).Table(Find.First());
int numRows = myTable.TableRows.Count;
List<string> myList = new List<string>();
for (int i = 1; i < numRows; i++)
{
myList.Add(myTable.TableRows[i].TableCells[1].Text);
}
I placed a label control on my form and I basically want it to increment in real time so I can see how fast the program is parsing the data.
On average I'm dealing with ~2000 rows, so it takes a long time, and I want to be able to see the status. The above code is using WatiN, but I'm sure this is a C# question.
Edit This was easier than I thought-
for (int i = 1; i < numRows; i++)
{
myList.Add(myTable.TableRows[i].TableCells[1].Text);
label1.Text = i.ToString();
}

You might want to use BackgroundWorker here so you are not blocking your UI and so you can provide status update through the BackgroundWorker