CODEWITHSUNDEEP
c#listview
Martijn
Martijn

Reputation: 24789

C# Clear all items in ListView

I try to clear my listview but the clear method doesn't work:

myListView.Items.Clear();

This doen't work. When i put a breakpoint at this line, the line is executed, but my listview isn't empty. How come??

I fill my listview by setting it's datasource to a datatable.

My solution now is to set the datasource to an empty datatable.

I just wonder why clear don't do the trick?

I use a master page. Here some code of a content page when a button is pressed. The method SearchTitle fills the ListView.

Relevant code:

        protected void Zoek()
    {
        // Clear listbox
        ListView1.DataSource = new DataTable();
        ListView1.DataBind();

        switch (ddlSearchType.SelectedValue)
        {
            case "Trefwoorden":
                SearchKeyword();
                break;
            case "Titel":
                SearchTitle();
                break;
            case "Inhoud":
                SearchContent();
                break;
        }
    }

Method that fills the ListView

        private void SearchTitle()
    {
        // Make panel visible
        pnlResult.Visible = true;
        pnlKeyword.Visible = false;

        Search Search = new Search(txtSearchFor.Text);
        ListView1.DataSource = Search.SearchTitle();
        ListView1.DataBind();
    }

Upvotes: 31

Views: 132509

Answers (12)

saurabh gupta
saurabh gupta

Reputation: 29

The Problem is arising because you are trying to clear the entire list box. Just use listView1.Items.Clear();

Upvotes: 2

user1656632
user1656632

Reputation:

I did a search on this and I am using WPF c#. Just in case you got here too looking for a WPF solution use the following:

yourlistview.ItemsSource = null;

Upvotes: 7

Zach Tuttle
Zach Tuttle

Reputation: 2341

This is bit late, but this works for me at least using UWP

myListView.ItemsSource = null;

Upvotes: 2

Jack Rohme
Jack Rohme

Reputation: 51

listView.Items.Clear()
listView.Refresh()

/e Updating due to lack of explanation. Often times, Clear() isn't suffice in the event of immediate events / methods following. It's best to update the view with Refresh() following a Clear() for an instant reflection of the listView clearing. This, anyhow had solved my related issues.

Upvotes: 3

nisan
nisan

Reputation: 37

Try with this:

myListView.ItemsSource = new List< DictionaryEntry >();

Upvotes: 1

Please help me
Please help me

Reputation: 81

Just use the clear method is works like a charm. ListView1.Items.Clear() i think if its not working it may be the position whereby you place this code. Also can try nullifying the datasource.

Upvotes: 0

Dave Howell
Dave Howell

Reputation:

Don't bother with Clear(). Just do this: ListView.DataSource = null; ListView.DataBind();

The key is the databind(); Works everytime for me.

Upvotes: 2

Serhat Ozgel
Serhat Ozgel

Reputation: 23766

Probably your code works but it is rebound somewhere after you clear it. Make sure that this it not the case. It will be more helpful if you provide some code. Where are you setting your data source? Where are you data binding? Where are you clearing the list?

Upvotes: 0

Martin Moser
Martin Moser

Reputation: 580

I would suggest to remove the rows from the underlying DataTable, or if you don't need the datatable anymore, set the datasource to null.

Upvotes: 0

Tony Basallo
Tony Basallo

Reputation: 3074

How about

DataSource = null;
DataBind();

Upvotes: 26

Treb
Treb

Reputation: 20271

My guess is that Clear() causes a Changed event to be sent, which in turn triggers an automatic update of your listview from the data source. So this is a feature, not a bug ;-)

Have you tried myListView.Clear() instead of myListView.Items.Clear()? Maybe that works better.

Upvotes: 4

JaredPar
JaredPar

Reputation: 754745

Try this ...

myListView.DataSource = null;
myListView.Items.Clear();

Upvotes: 23

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