I have a directory form which displays the contents of a CSV file in a listview upon load. I am creating a button that sends three user-entered text fields to the CSV file, clears the form textboxes and listview, then loads and displays the updated directory in the listview.
Unfortunately, when the button is clicked, I instead end up with a blank listview, even though the clearForm method comes before loadDirectory and displayDirectory. When I comment out the clearForm function, my listview contains the original list followed by the entire new list, as expected.
private void BtnAddNew_Click(object sender, EventArgs e)
{
addRecord(); // Sends text box entries to a file via. streamreader *working*
clearForm(); // Clears the form *working on standalone clear button*
loadDirectory(); // Loads CSV file contents to array *working*
displayDirectory(); // Displays array to listview *working*
}
public void loadDirectory()
{
StreamReader sr = new StreamReader(path);
int lineCount = File.ReadLines(path).Count();
string line;
int count = -1;
directoryTable = new record[lineCount];
while (!sr.EndOfStream)
{
count++;
line = sr.ReadLine();
string[] fields = line.Split(',');
record currentRecord = new record();
currentRecord.surname = fields[0];
currentRecord.forename = fields[1];
currentRecord.extCode = Convert.ToInt32(fields[2]);
directoryTable[count] = currentRecord;
}
sr.Close();
}
public void displayDirectory()
{
for (int counter = 0; counter < directoryTable.Length; counter++)
{
ListViewItem lvi = new ListViewItem();
lvi.Text = (Convert.ToString(directoryTable[counter].surname));
lvi.SubItems.Add(Convert.ToString(directoryTable[counter].forename));
lvi.SubItems.Add(Convert.ToString(directoryTable[counter].extCode));
lvDirectory.Items.Add(lvi);
}
}
public void addRecord()
{
string[] newRecord = new string[3];
newRecord[0] = txtForename.Text;
newRecord[1] = txtSurname.Text;
newRecord[2] = txtExtCode.Text;
// Write newRecord array to last line of directory file
StreamWriter sw = new StreamWriter(path, append: true);
sw.WriteLine(newRecord[0] + ", " + newRecord[1] + ", " + newRecord[2]);
sw.Close();
}
public void clearForm()
{
foreach (Control field in Controls)
{
if (field is TextBox)
((TextBox)field).Clear();
else if (field is ListView)
((ListView)field).Clear();
}
}
You need to clear the items in the listview and not the listview itself:
public void clearForm()
{
foreach (Control field in Controls)
{
if (field is TextBox)
((TextBox)field).Clear();
else if (field is ListView)
((ListView)field).Items.Clear();
}
}