Read file from listbox

Question

I have some code that will load full file names (ex.F:\\logs\\1234.log) into a listbox depending on the directory the user chooses. When the user selects one or more of the files and clicks the output button, I want the code to read through each selected file. Before, I was using a combobox and the code:

StreamReader sr = new StreamReader(comboBox1.Text);

This obviously does not work for listboxes. What is the simplest way to have the program read the user selected file(s) from the listbox?

Answer 1

You should have been more clear in your original question... but if you need to read all the files:

        var items = listBox.SelectedItems;
        foreach (var item in items)
        {
            string fileName = listBox.GetItemText(item);
            string fileContents = System.IO.File.ReadAllText(fileName);
            //Do something with the file contents
        }

Answer 2

If you are choocing one file per time to open, then a solution would be as follows:

string[] files = Directory.GetFiles(@"C:\");
listBox1.Items.Clear();
listBox1.Items.AddRange(files);

Then, to get to the file path selected:

if (listBox1.SelectedIndex >= 0)
{ // if there is no selectedIndex, property listBox1.SelectedIndex == -1
       string file = files[listBox1.SelectedIndex];
       FileStream fs = new FileStream(file, FileMode.Open);
       // ..
}

Answer 3

What you can do it to create a generic list, which will hold all the text from selected files:

    void GetTextFromSelectedFiles()
    {
        List<string> selectedFilesContent = new List<string>();
        for (int i = 0; i < listBox1.SelectedItems.Count; i++)
        {
            selectedFilesContent.Add(ReadFileContent(listBox1.SelectedItems.ToString()));
        }

        //when the loop is done, the list<T> holds all the text from selected files!
    }

    private string ReadFileContent(string path)
    {
        return File.ReadAllText(path);
    }

I think in your example when you explicitly said "as simple as possible" to read the file, would be best to use File.ReadAllText() method, better then using StreamReader class.

Answer 4

To access all selected items in a ListBox you can use the SelectedItems property:

foreach (string value in listBox1.SelectedItems)
{
    StreamReader sr = new StreamReader(value);
    ...
}