I have an application which must contain the items in large quantities and continuously into listviews control:
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
deg_loadfile load = new deg_loadfile(loadfile);
load.BeginInvoke(new AsyncCallback(loadcallback),null);
}
void countfile() {
int listcount = listView1.Items.Count;
for (int x = 0; x < listcount; x++) {
listView1.BeginInvoke((MethodInvoker)delegate {
listView1.Items[x].SubItems[1].Text = "ok";
listView1.Items[x].SubItems[2].Text = "ok";
listView1.Items[x].SubItems[3].Text = "done";
},x);
}
}
void countcallback(IAsyncResult ae) {
MessageBox.Show("count finished");
}
delegate void deg_count();
void loadcallback(IAsyncResult ae) {
MessageBox.Show("finished");
}
delegate void deg_loadfile();
void loadfile() {
string file = File.ReadAllText("hughlist.txt");
string[] files = Regex.Split(file,"\n");
foreach (string str in files) {
listView1.BeginInvoke((MethodInvoker)delegate {
ListViewItem item = new ListViewItem(str);
item.SubItems.Add("");
item.SubItems.Add("");
item.SubItems.Add("");
listView1.Items.Add(item);
},str);
}
}
private void button2_Click(object sender, EventArgs e)
{
deg_count count = new deg_count(countfile);
count.BeginInvoke(new AsyncCallback(countcallback),null);
}
The code above throws system.argumentoutofrangeexception (please see image below)
link image: https://i.sstatic.net/WJ7sA.png
The iteration has exceeded the conditions that I have given, why did it happen (note:in my case, i must use "for" instead of "foreach" or other enumeration) ?
thx
UPDATE: thx to @saruman for the answer (keyword is "access to modified closure"), i've updated the code as below
for (int x = 0; x < listcount; x++) {
var x1=x;
listView1.BeginInvoke((MethodInvoker)delegate
{
listView1.Items[x1].SubItems[1].Text = "ok";
listView1.Items[x1].SubItems[2].Text = "ok";
listView1.Items[x1].SubItems[3].Text = "done";
}, x1); }
Look up access to modified closure
Try this
var listcount = listView1.Items.Count;
for (var x = 0; x < listcount; x++)
{
var x1 = x;
listView1.BeginInvoke((MethodInvoker)delegate
{
listView1.Items[x1].SubItems[1].Text = "ok";
listView1.Items[x1].SubItems[2].Text = "ok";
listView1.Items[x1].SubItems[3].Text = "done";
});
}