C# Loop limited to 50 passes

Question

How do I limit the loop below to 50 so it stops when it reaches the 51st item?

foreach (ListViewItem lvi in listView.Items)
{

}

Thanks

Answer 1

Use a for loop.

for(int index = 0; index < collection.Count && index < 50; index++)
{
   collection[index];
}

Answer 2

foreach (ListViewItem lvi in listView.Items) {
  // do code here
  if (listView.Items.IndexOf(lvi) == 49)
    break;
}

OR since it is a list view item

foreach (ListViewItem lvi in listView.Items) {
  // do code here
  if (lvi.Index == 49) break;
}

Using Linq as Per LukeDuff

foreach (ListViewItem lvi in listView.Items.Take(50)) {
  // do code here
}

Using For Loop as Per Atomiton

// loop through collection to a max of 50 or the number of items
for(int i = 0; i < listView.Items.Count && i < 50; i++){
    listView.Items[i]; //access the current item

}

Answer 3

Well, the foreach may not be the best solution, but if you must:

int ctr = 0;
foreach (ListViewItem lvi in listView.Items) {
    ctr++;
    if (ctr == 50) break;

    // do code here

}

Note: a for loop is generally lighter than using a foreach to go through a collection.

Better to use a for loop:

// loop through collection to a max of 50 or the number of items
for(int i = 0; i < listView.Items.Count && i < 50; i++){
    listView.Items[i]; //access the current item

}

Answer 4

If you want to still use a foreach loop try the following:

int counter = 0;
foreach (ListViewItem lvi in listView.Items) 
{
  counter++;
  if ( counter == 50 )
  {
   break;
  }
}

Answer 5

I would use a for loop as charles suggested instead of a foreach with an index check. The intent is more obvious as a for loop is used when you need to keep track of the current iteration.

for (int i = 0; i < listView.Items.Count && i < 50; ++i)
{
    //do something with listView.Items[i]
}

Answer 6

int i = 50;
foreach(T t in TList)
{
   if(i-- <= 0) break;

   code;

   // or: i--; if(i<=0) break;
}

Answer 7

for(int index = 0; index < Math.Min(50, collection.Count); index++)
{
   collection[index];
}

Answer 8

for (int i = 0; i < 50 && i < listView.Items.Count; ++i)
{
    ListViewItem item = listView.Items[i];
}

Answer 9

People have given plenty of examples, and in this specific case since ListView.Items is an indexed collection, an old fashioned for loop is probably best. If it were something like an IEnumerable where you couldn't use Items[i] then you'd have to do like the other examples with an external counter variable.

Answer 10

Easy with Linq

foreach (ListViewItem lvi in listView.Items.Take(50)) {

}

From the MSDN documentation:

Take<(Of <(TSource>)>) enumerates source and yields elements until count elements have been yielded or source contains no more elements.

If count is less than or equal to zero, source is not enumerated and an empty IEnumerable<(Of <(T>)>) is returned.

Answer 11

A for loop will work, but you can still setup a ListViewItem named lvi like so.

int maxItems = listViewItems.Count > 50 ? 50 : listViewItems.Count;
for(int counter = 0; counter < maxItems; counter ++)
{ 
    ListViewItem lvi = listView.Items[counter];

    // Rest of your code here will stile work

}

Answer 12

Using LINQ, this could be implemented as:

foreach (ListViewItem lvi in listView.Items.Take(50))
{
  // do stuff
}

Take(n) returns the first n elements or all element if less than n are available.