I have a datagridview which gets filled with data returned from a linq query. If the query returns no results I want to display a messagebox. Is there a way of checking to see if the datagridview is empty?
Regards
You can find out if it is empty by checking the number of rows in the DataGridView. If myDataGridView.Rows.Count == 0
then your DataGridView is empty.
The DGV.Rows.Count
method of checking if DGV is empty does not work if the option AllowUserToAddRows
is set to true.
You have to disable AllowUserToAddRows = false
then check for empty like this:
if (dataGridView1.Rows != null && dataGridView1.Rows.Count != 0)
//this gives rows count=1
if (dataGridView1.Rows.Count != 0 && dataGridView1.Rows != null)
//so finally I modifieded code as below and it works for me
if(dataGridView1.Rows.Count>1 && dataGridView1.Rows != null)
A lot of answers here have a reference to Rows.Count
. Normally, that does not pose a problem and it would in most cases be an overkill to do what I am about to suggest.
But for reasons mentioned in this document it may not be a good idea to call Rows.Count
if the DataGridView
frequently has a lot of data ( >~ 5000
cells in the memory profiling I did to validate that article a while back).
Avoid using the
Count
property of theSystem.Windows.Forms.DataGridViewSelectedCellCollection
to determine the number of selected cells. Instead, use theDataGridView.GetCellCount
method and pass in theDataGridViewElementStates.Selected
value. Similarly, use theDataGridViewRowCollection.GetRowCount
andDataGridViewColumnCollection.GetColumnCount
methods to determine the number of selected elements, rather than accessing the selected row and column collections.
In such cases you can use
myDataGridView1.Rows.GetRowCount(.) == 0
If you are not dealing with fast changing data or a huge amount of data (or worse, huge amount of fast changing data) then simply use Rows.Count --it does not hurt that much.
Based on the Linq results, you can hide the datagridview and show some other control (like a Literal or something) that shows the message. If you want some sort of messagebox popup, you'd need to throw some JavaScript in there.
这应该这样做:
dataGridView1.RowCount == 0
You can check the Rows.Count property of the datagridview.
Although you might also want to look into the EmptyDataText property of the DataGridView. It might save you showing a messagebox.
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