C＃DataGridView检查是否为空

Question

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

Answer 1

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.

Answer 2

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)

Answer 3

//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)

Answer 4

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 the System.Windows.Forms.DataGridViewSelectedCellCollection to determine the number of selected cells. Instead, use the DataGridView.GetCellCount method and pass in the DataGridViewElementStates.Selected value. Similarly, use the DataGridViewRowCollection.GetRowCount and DataGridViewColumnCollection.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.

Answer 5

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.

Answer 6

这应该这样做：

dataGridView1.RowCount == 0

Answer 7

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.