How to reload datagrid in wpf

Question

I have a WPF application where I want to select item from datagrid and pass to textbox. after that on add button selected gridrow must be remove. I have a stored procedure to remove from table. And at same time reload the table in same datagrid.

I tried this code

private void refresh()
{
    datagrid1.items.refresh();
}

private void btnAdd_Click(object Sender, RoutedEventArg e)
{
    refresh();
}

private void datagrid1_SelectionChange(object Sender, RoutedEventArg e)
{
     var selectedrow = datagrid1.selectedItem as datarowview;
     var id = selectedrow["Tagid"]; // Here I get error that object reference is not set is an instance of an object 
    string s = conver.tostring(id);
    txttextbox1.text= s;
}

After click add button, I get the error

Object reference not set to an instance of an object

I'm guessing that the error occurs in your **referesh()** method. What exactly is null? Is it the **datagrid1** or the **datagrid1.items**? Also [please see this question](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Mike Eason, Mar 18 '15 at 10:19
it would be easier if you look at mvvm, there you just handle the collection and the datagrid is "refreshed" automatic with the right bindings :) — blindmeis, Mar 18 '15 at 10:29
@ Mike eason- actually datagrid1 not relode or refresh by using datagrid1.items.referesh(); In refresh() I just do datagrid1.items.referesh(); — Dipika, Mar 18 '15 at 10:30

score 0 · Accepted Answer · edited Feb 24 '19 at 15:37

0

You are forcing your selected item as datarowView which it is not, cast to correct type

var selectedrow = datagrid1.selectedItem as DataRowView

SelectedItem is type of object that is bound to grid not row

Try doing this

private void datagrid1_SelectionChange(object Sender, RoutedEventArg e)
{
    var selectedItem = datagrid1.selectedItem as MY_Custom_Object;
    var id = selectedItem.Tagid; 
    string s = Convert.ToString(id);
    txttextbox1.text= s;
}

edited Feb 24 '19 at 15:37

marc_s

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answered Mar 18 '15 at 10:42

Muds

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@ Muds - "My_custom_object" Is which datatype? – Dipika Mar 18 '15 at 11:01
its same data type that you bound to your grid,.... I am assuming dataGrid1 has an itemsource ... itemsource is usually IEnumerable.. so whatwver your list is .. that's your datatype... – Muds Mar 18 '15 at 11:04
hint: its the datatype that has Tagid – Muds Mar 18 '15 at 11:05
Thanks for valuable answer. But still not get that "My_Custom_object" I am new for wpf. Will you plz elaborate in detail – Dipika Mar 18 '15 at 11:40
– Dipika Mar 18 '15 at 11:57
where do you set itemssource ? – Muds Mar 18 '15 at 11:58
which object contains tagid ? – Muds Mar 18 '15 at 11:58
Create Seperet Fuction To aad data in datagried 'private void adddata() { ds = obj.update("SpName"); dt= ds.table[o]; datagried1.itemssource= dt.defaultview;}' – Dipika Mar 18 '15 at 12:03
what is datatype of data ? – Muds Mar 18 '15 at 12:04

How to reload datagrid in wpf

1 Answers1