c# - How do i make instance for array of ToolStripMenuItem items? -

in top of form1:

toolstripmenuitem[] items; 

in constructor:

for (int = 0; < items.length; i++) {     items[i] = new toolstripmenuitem();     recentfilestoolstripmenuitem.dropdownitems.addrange(items); }  if (!file.exists(@"e:\recentfiles.txt")) {     recentfiles = new streamwriter(@"e:\recentfiles.txt");     recentfiles.close(); } else {     lines = file.readalllines(@"e:\recentfiles.txt"); } 

before used single item , made 1 instance in top of form1. want add dropdownitems array of items. , don't how many items want unlimited.

then have event:

private void recentfilestoolstripmenuitem_mouseenter(object sender, eventargs e) {     (int = 0; < lines.length; i++)     {         items[i].text = lines[i];     }             } 

when used single item did in mouseenter event:

item.text = "hello world"; 

but want add items text file can 1 items or 200 items problem items null in constructor.

i did in constructor changed to:

if (!file.exists(@"e:\recentfiles.txt")) {     recentfiles = new streamwriter(@"e:\recentfiles.txt");     recentfiles.close(); } else {     lines = file.readalllines(@"e:\recentfiles.txt");     items = new toolstripmenuitem[lines.length]; } 

in case lines.length 3. when on items see 3 items each 1 of them null. know how many items need instance reason null.

it seems, main problem in fact don't know in advance length of items[]; such problem task linq, that:

  private toolstripmenuitem[] items;    ... 

in constructor:

  items = file     .readlines(@"e:\recentfiles.txt")     .select(line => new toolstripmenuitem() {        text = line      })     .toarray();   ...   // if items used in addrange   // have no need neither of toarray() nor in private field   recentfilestoolstripmenuitem.dropdownitems.addrange(items); 

in case want, say, 10 first recent files only:

  items = file     .readlines(@"e:\recentfiles.txt")     .take(10)     .select(line => new toolstripmenuitem() {        text = line      })     .toarray();