I'm trying to remove all users from an AD group with the following code:
private void RemoveStudents() {
foreach (DirectoryEntry childDir in rootRefreshDir.Children) {
DirectoryEntry groupDE = new DirectoryEntry(childDir.Path);
for (int counter = 0; counter < groupDE.Properties["member"].Count; counter++) {
groupDE.Properties["member"].Remove(groupDE.Properties["member"][counter]);
groupDE.CommitChanges();
groupDE.Close();
}
}
}
The rootRefreshDir is the directory that contains all the AD groups (childDir).
What I'm finding here is that this code does not behave correctly. It removes users, but it doesn't do it after the first run. It does "some". Then I run it again, and again, and again - depending on how many users need to be deleted in a group. I'm not sure why it's functioning this way.
Can someone help fix this code or provide an alternative method to delete all users in a group?
You're looping through the items as you delete them causing the index to skip every other item.
You need to change the inner for loop to loop backwards, like this:
PropertyValueCollection members = groupDE.Properties["member"];
for (int counter = members.Count - 1; counter >= 0; counter--) {
members.RemoveAt(counter);
groupDE.CommitChanges();
groupDE.Close();
}
Your problem is that you're counting upwards... You first remove an item at index 0. Every remaining item then moves to index - 1 in the list. You then remove at index 1, and every remaining item shuffles except for the one you've now left at index 0. Basically: you're only removing half of the items.
Instead of a for loop, try while (groupDE.Properties["member"].Count > 0), and simply remove the item at index 0 each time.
Or if you are using
DirectoryServices.AccountManagement.GroupPrincipal (.NET 3.5+):
This will work as well:
groupPrincipal.Members.Clear();
groupPrincipal.Save();
just use:
group.Properties["member"].Clear();
group.CommitChanges();
This reference in CodeProject should help:
"How To Do (almost) Everything in AD:
http://www.codeproject.com/KB/system/everythingInAD.aspx
Related
I have been researching this topic and got conflicting answers. Any help is appreciated.
For an assignment, I am instructed to create a structure of arrays. I am trying to delete an entry in one case, and change in another. This is supposed to be by one of the fields and not by index number.
var countOfEmployees = 0;
var employees = new EmployeeData[100];
Console.Write("Please enter employee you want to delete:");
string deleteEmployee = Console.ReadLine();
bool deleted = false;
for (int x = 0; x < countOfemployees; x++)
{
if (items[x].ItemNumber == deleteItemNumber)
{
deleted = true;
}
if (true)
{
//code goes here
}
Any help is appreciated!
In an array, you might be able to delete the value from the place holder, but you will not be able to remove the actual item without some footwork.
Basically, what you can do is: Find the value you've searched for, and replace it with a null and treat it orrespondingly in every other function.
Option 2 would be to remove the item and then use a function that would "shift" all the values with a higher index upwards.
Option 3 is to use the advanced functions C#/.NET has to offer with collections, create a List, remove the item and cast back to an array.
var employees = new EmployeeData[100];
var list = employees.ToList();
int index=-1;
//search through in a loop (won't write it here)...
index = x; //get the index in your list then break the loop
break; //end the loop
list.RemoveAt(index); //delete the spot outside the loop
employees=list.ToArray();
Of course there's checks needed if the search didn't find anything, but i think you can manage to implement that without my help.
And this is of course me assuming that there's only ONE entry with that kind of value in the array.
If it's not, you're gonna have to loop through and erase them until the search doesn't find anything anymore.
I have tried to get the point across in the title as best as I can but basically what I want to do is add certain items to List while running a loop so I don't have to manually put them into an if statement. Let me please show an example so that I can explain properly.
Example :-
What I need is :- the first number would be 500 and that would be in index 0, then i want a loop to add 150 to the last number generated so that the int list would look like this,
index 0 = 500
index 1 = 650
index 2 = 800
index 3 = 950
Do this repeatedly until say the last number will read 2,000,000
Now I believe that this would be simple to run a loop and base it on conditions but I can only seem to figure out to run a loop that will increment the value in 1.
Hope I have explained well enough
Regards,
M
Now I believe that this would be simple to run a loop and base it on
conditions but I can only seem to figure out to run a loop that will
increment the value in 1.
This is not true, you can adjust the increment of the iterator as you wish.
var numbers = new List<int>();
for(int i=500; i<=2000000; i+=150)
{
numbers.Add(i);
}
For further information on this, please have a look here.
Just another implementation:
var result = new List<int>();
var number = 500;
do
{
result.Add(number);
number+= 150;
} while (number <= 2000000);
My current code:
Remove()
{
for (int i = 0; i < ConGridView.RowCount; i++)
{
if (ConGridView.Rows[i].Cells[0].Value.ToString() == Address)
{
ConGridView.Rows.RemoveAt(i);
break;
}
}
}
So what I am trying to call the remove function every time a client disconnect. the function will remove the connection address from the datagridview. It works well when clients are disconnection one by one. However, if 100 connections gets dropped and it tries to remove 100 connections in less than a second, than it errors out saying "Row Index provided is out of range". How should I check for that ?
So far I've tried:
Try, catch.
if (ConGridView.Rows[i] != null), if (i < ConGridView.RowCount)
None of it seem to work so far. I've also got results using (i < ConGridView.RowCount) where i is 26 while RowCount is 24, but the remove at function still activates..
Any idea on this ?
You can't do this. Your code loops through all the rows in ConGridView, but it deletes them as you do. Therefore, at some point you will try to access an item you have deleted, which will cause the error you described.
Probably the best approach it to iterate through the rows in reverse order. This way, deleting a row at the end won't affect when you access rows at the start.
The problem is you initialise your for loop with the current count of rows and then start removing those same rows from the datagridview. At some point your for loop will try to remove a row at an index that is greater than the number of rows left.
Try this instead:
for (int i = ConGridView.RowCount - 1; i >= 0; i--)
{
if (ConGridView.Rows[i].Cells[0].Value.ToString() == Address)
{
ConGridView.Rows.RemoveAt(i);
break;
}
}
why dont you get the total count to a separate variable and then iterate
Remove()
{
int totalConnections = ConGridView.RowCount;
for (int i = 0; i < totalConnections ; i++)
{
if (ConGridView.Rows[i].Cells[0].Value.ToString() == Address)
{
ConGridView.Rows.RemoveAt(i);
break;
}
}
}
This issue is becuase you are modifying the collection your are iterating over. It will be better if you use a temporary array and two loops to remove your entries.
Remove()
// You can use an array/list or whatever you want below.
Collection<DataGridViewRow> rowsToDelete = new Collection<DataGridViewRow>();
for (int i = 0; i < ConGridView.RowCount; i++)
{
if (ConGridView.Rows[i].Cells[0].Value.ToString() == Address)
{
rowsToDelete.Add(ConGridView.Rows[i]);
break;
}
}
// now remove the marked entries.
foreach(DataGridViewRow deletedRow in rowsToDelete)
{
ConGridView.Rows.Remove(deletedRow);
}
When you remove an item from an array, it is reconstructed; shifting the remaining elements up by one to remove the gap of the index you have removed.
1. guybrush threepwood
2. murray
3. elaine
4. Jimmy Gibbs Jr.
If you remove 2. item in here; it becomes this:
1. guybrush threepwood
2. elaine
3. Jimmy Gibbs Jr.
When you are iterating, imagine:
for (int i = 0; i < myArray.Count; i++)
{
if (i == 2) myArray.RemoveAt(i);
}
While running this, when i = 3, the element at 3 has changed, you expect it to be 'elaine' but it is 'Jimmy Gibbs Jr.'. One way to fix this is decrease i by one if we delete it, making sure that i refers to correct value.
for (int i = 0; i < myArray.Count; i++)
{
if (i == 2)
{
myArray.RemoveAt(i);
i--;
}
}
I would go for LINQ in this case, though, everything is easier with that.
myArray.RemoveAll(x => x == "murray");
I've tried all the suggestions posted by everyone here, however, the error was still there.
I've solved the problem using a different way... I've switched to TreeNodeView since that's what I was going to use ultimately. Now I can remove as many connection as i want with:
For each(TreeNode TN in ConTreeView)
{
ConTreeView.Nodes.Remove(TN);
}
I'm trying to see if when a user enters some text it searches the array for any matches, and whatever doesn't match gets removed from the array;
string search = textBox1.Text;
for (int i = 0; i < staffUsers.Count; i++)
{
if (!(staffUsers[i].staff_name.Contains(search)))
{
staffUsers.Remove(staffUsers[i]);
}
}
I have some rubbish names in my array 'Rob Dob','Joe Bloggs', 'h h', 'ghg hgh', and if the search variable ended up being 'R', Joe Bloggs would get removed but 'h h' and 'ghg hgh' stay there, but there is no R involved there at all? any reason why>?!
You have to iterate backwards in order to remove from an array. Every time you remove an item, your array gets smaller. By going backwards, that fact does not matter.
string search = textBox1.Text;
for (int i = staffUsers.Count - 1; i >= 0 ; i--)
{
if (!(staffUsers[i].staff_name.Contains(search)))
{
staffUsers.Remove(staffUsers[i]);
}
}
The problem with your code is that you are removing items as you iterate over it. You remove an item, but keep iterating, even though the size of the array changes when you remove an item.
You need to reset your i value after you remove something. Alternatively, you need to use a built in to do the heavy lifting:
staffUsers.RemoveAll(i => !(i.staff_name.Contains(search)));
Uses a tiny LINQ expression to do the work. Remove all items where that predicate matches. i represents an item to apply the expression to. If that expression evaluates to true, away it goes.
Long story short, whenever you remove an item at index [i], you skip the item at index [i+1]. For example, if your array looks like:
{'Joe Bloggs', 'Rob Dobb', 'h h', 'gafddf'}; i=0
remove Joe Bloggs, which is at position 0.
{Rob Dobb', 'h h', 'gafddf'}; i=1
remove 'h h', which is at position 1
{Rob Dobb', 'gafddf'}; i=2
i is not less than yourArray.Count, so the loop stops. There is no position 2.
The quickest fix is to add i-- if you remove something from index [i]. In your case,
staffUsers.Remove(staffUsers[i]);
i--;
Hope this helps!
In each iteration of the loop, either remove an item or increment the counter, not both operations. Otherwise, you'll skip the next array element whenever you remove an array element:
string search = textBox1.Text;
for (int i = 0; i < staffUsers.Count;)
{
if (!(staffUsers[i].staff_name.Contains(search)))
{
staffUsers.Remove(staffUsers[i]);
}
else
{
i++;
}
}
The simplest way to solve the above problem is using LINQ.
Following code disentangle above problem.
string search = textBox1.Text;
staffUsers= (from user in staffUsers
where !user.Contains(search)
select user).ToArray<string>();
Note: I assumed staffUsers is array of string.
string search = textBox1.Text;
for (int i = 0; i < staffUsers.Count; i++)
{
if (!(staffUsers[i].staff_name.Contains(search)))
{
staffUsers.Remove(staffUsers[i]);
// reset the index one stepback
i--;
}
}
Why doesn't the code below clear all array list data?
Console.WriteLine("Before cleaning:" + Convert.ToString(ID.Count));
//ID.Count = 20
for (int i = 0; i < ID.Count; i++)
{
ID.RemoveAt(i);
}
Console.WriteLine("After cleaning:" + Convert.ToString(ID.Count));
//ID.Count = 10
Why is 10 printed to the screen?
Maybe there is another special function, which deletes everything?
You're only actually calling RemoveAt 10 times. When i reaches 10, ID.Count will be 10 as well. You could fix this by doing:
int count = ID.Count;
for (int i = 0; i < originalCount; i++)
{
ID.RemoveAt(0);
}
This is an O(n2) operation though, as removing an entry from the start of the list involves copying everything else.
More efficiently (O(n)):
int count = ID.Count;
for (int i = 0; i < originalCount; i++)
{
ID.RemoveAt(ID.Count - 1);
}
or equivalent but simpler:
while (ID.Count > 0)
{
ID.RemoveAt(ID.Count - 1);
}
But using ID.Clear() is probably more efficient than all of these, even though it is also O(n).
`Array.Clear()`
removes all items in the array.
`Array.RemoveAt(i)`
removes the element of ith index in the array.
ArrayList.Clear Method
Removes all elements from the ArrayList.
for more detail : http://msdn.microsoft.com/en-us/library/system.collections.arraylist.clear.aspx
After removing 10 items, ID.Count() == 10 and i == 10 so the loop stops.
Use ID.Clear() to remove all items in the array list.
Use the clear() Method
or
change ID.RemoveAt(i); to ID.RemoveAt(0);
Whenever an element is removed from the collection, its index also changes. Hence when you say ID.RemoveAt(0); the element at index 1 now will be moved to index 0. So again you've to remove the same element (like dequeuing). until you reach the last element. However if you want to remove all the elements at once you can better use the Clear() method.
Your code does:
ID.RemoveAt(0);
...
ID.RemoveAt(9);
ID.RemoveAt(10); \\ at this point you have already removed 10
\\ items so there is nothing left on 10- 19, but you are left with
\\ the 'first' 10 elements
...
ID.RemoveAt(19);
Generally speaking your method removes every second element from the list..
Use ArrayList.Clear instead as other have mentioned.