Datagrid problem with paging and check boxes...

viktors

hi all, i have a datagrid with a display checkbox column and the datagrid supports paging. paging is working fine but when i change the page the checked items on the previous page are not being retained. only values checked in the last page are being retained..how can i retain all the checked items from all the pages.. thank's my code looks something like this: Select private void Page_Load(object sender, System.EventArgs e) { if (!IsPostBack) { sql = "select * from table1 where type=" + "'"+ mytext +"'" + "order by id"; People.DataSource = CreateDataSource(); People.DataBind(); } } public void Page_Grid(Object sender, DataGridPageChangedEventArgs e) { sql = "select * from table1 where type=" + "'"+ mytext +"'" + "order by id"; // Set CurrentPageIndex to the page the user clicked. People.CurrentPageIndex = e.NewPageIndex; // Rebind the data. People.DataSource = CreateDataSource(); People.DataBind(); } public ICollection CreateDataSource () { //getting the connection from the web.config file. SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["connString"]); SqlDataAdapter db_sqladaptor = new SqlDataAdapter(sql,conn); DataSet ds = new DataSet(); db_sqladaptor.Fill(ds,"MyDataResult"); DataView myView = ds.Tables["MyDataResult"].DefaultView; conn.Close(); return myView; } private void Button1_ServerClick(object sender, System.EventArgs e) { DataGridItemCollection items = People.Items; for (int i=0; i

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fredo_lefran22y ago
Hello, I'm programing in c# an web application which i'm a datagrid and i would like to insert a checkbox column. So i used that you wrote but i haven't good result. in fact, the value checkbox is always false. I think it OnCheckedChanged event doesn't work. Can you help me please?
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S_Kiryazov22y ago
I'm still sleepy and I may be missing something but here is what I think. Can't you directly access the header checkbox in the codebehind? And just set the appropriate value when CheckedChanged event is fired? Or maybe the better solution is to do this on the client side. Just attach a javascript handler for the onClick event for every checkbox in the grid that does the job
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sacresp22y ago
I have somewhat similar situation. Except that I've provided a check box to HeaderTemplate (it is used to [de]select all checkboxes at all rows at all apges). The problem is, when I uncheck a checkbox at any row, this "CheckAll" checkboxes should also be uncheked. How do I do that? I tried to get handle to the control by using MyDatagrid.FindControl("CheckAll") but it returns null.
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viktors22y ago
oops, what a silly mistake... please disregard the earlier post..
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viktors22y ago
thanks stefan, i am able to trap the checked items on each page....just that all the checkboxes are already checked on the page...i have to deselect individual items to get the values... is there any way i can do it the other way round? i.e initially everything is blank and then i check each item..and then get those values.. You mentioned about :On the server you've got to subscribe for the CheckedChanged event and mark in some kind of data structure which checkboxes are checked. A neat idea is to have a boolean datacolumn in the dataset, so in your checkbox in the datagrid you have something like Checked='<%# Convert.ToBoolean( DataBinder.Eval(Container.DataItem, "Selected") )%>' i didn't understand this part... how do i get a boolean datacolumn in the dataset?? hence i am passing it as Checked='<%# Convert.ToBoolean(DataBinder.Eval(Container.DataItem, "typical_id") )%>' this is how it looks now:
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S_Kiryazov22y ago
I haven't heard of a built-in solution for this but I have a workaround in mind. On the server you've got to subscribe for the CheckedChanged event and mark in some kind of data structure which checkboxes are checked. A neat idea is to have a boolean datacolumn in the dataset, so in your checkbox in the datagrid you have something like Checked='<%# Convert.ToBoolean( DataBinder.Eval(Container.DataItem, "Selected") )%>' and on the server you need only to switch the boolean value for the appropriate row in the table when the CheckedChanged event is fired. By default, the CheckedChanged event does not cause a postback so all the event handlers are queued till the current page is changed or the button is clicked. There are some further difficulties though. The CheckedChanged event is an ordinary EventHandler event which means that the current row or any other data than can help you locate the exact checkbox that has been checked/unchecked is not supplied through the EventArgs. A way to work this around is to set the FilterKey property of the CheckBox to a value that uniquely describes the row that has been checked and then get it from the sender object passed to the event handling method - like this: FilterKey='<%# DataBinder.Eval(Container.DataItem, "UserID")%>' Here's some of my samle code: ... ' OnCheckedChanged="CheckedChanged" Name='<%# DataBinder.Eval(Container.DataItem, "UserID")%>' width="20" /> protected void CheckedChanged( Object sender, EventArgs a ) { Int32 ID = Convert.ToInt32(((CheckBox)sender).Attributes["FilterKey"]); // Switch the value in the dataset } I remember that I had some problems with the senders of the events getting mixed up but I don't remember exactly what it was. If you notice curious event handler behaviour describe it to help me recall it.
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