<div>
Can you paste the current code?
</div>

<div>
When the user types in a number in the 'Search' box this is called: 

<pre><code class="code-10 nolinks" id="code-20-41753919-1">private void txtSearch_KeyUp(object sender, KeyEventArgs e)
 {
if (e == null || e.KeyCode == Keys.Enter)
 {

 //Clear the datasource and datagridview so everything is starting from scratch
 if (HeaderCheckBox != null)
 {
 HeaderCheckBox.CheckState = CheckState.Unchecked;
 }
 dgBilling.DataSource = null;
 dgBilling.Rows.Clear();
 dgBilling.Columns.Clear();
 dgBilling.ColumnCount = 0;
 
 BindBillGrid(sSCH, sdb); 
}
</code></pre>
 
Here is my code to create and populate the datagridview: 

<pre><code class="code-100 nolinks" id="code-20-41753919-2">private void BindBillGrid(string sSCH, Boolean sdb)
 {
DataSet ds = new DataSet();

 IsLoadBillGrid = true;

 string strSQL = &quot;My sql statement here&quot;;
 SqlConnection connection = new SqlConnection(Cm.adrl);
 SqlDataAdapter dataadapter = new SqlDataAdapter(strSQL, connection);
 connection.Open();
 dataadapter.Fill(ds);
 connection.Close();
 //Set AutoGenerateColumns False 
 dgBilling.AutoGenerateColumns = false;

 //Set Columns Count
 dgBilling.ColumnCount = 8;

 //Add Columns 
 DataGridViewCheckBoxColumn clsCol2 = new DataGridViewCheckBoxColumn();
 clsCol2.HeaderText = &quot;&quot;;
 clsCol2.ValueType = typeof(System.Boolean);
 clsCol2.Width = 55;
 clsCol2.Name = &quot;dgcChecked&quot;;
 clsCol2.DataPropertyName = &quot;Checked&quot;;
 clsCol2.SortMode = DataGridViewColumnSortMode.Automatic;
 clsCol2.FalseValue = false;
 clsCol2.TrueValue = true;
 dgBilling.Columns.Insert(0, clsCol2);
 
 AddHeaderCheckBox();
 HeaderCheckBox.KeyUp += new KeyEventHandler(HeaderCheckBox_KeyUp);
 HeaderCheckBox.MouseClick += new MouseEventHandler(HeaderCheckBox_MouseClick);
 dgBilling.CellValueChanged += new DataGridViewCellEventHandler(dgBilling_CellValueChanged);
 dgBilling.CurrentCellDirtyStateChanged += new EventHandler(dgBilling_CurrentCellDirtyStateChanged);
 dgBilling.CellPainting += new DataGridViewCellPaintingEventHandler(dgBilling_CellPainting);
 
 dgBilling.Columns[1].Name = &quot;dgcMatterID&quot;;
 dgBilling.Columns[1].HeaderText = &quot;Matter ID&quot;;
 dgBilling.Columns[1].DataPropertyName = &quot;matter_code&quot;;
 dgBilling.Columns[1].Width = 103;
 dgBilling.Columns[1].ReadOnly = true;
 dgBilling.Columns[1].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;

 dgBilling.Columns[2].Name = &quot;dgcDescription&quot;;
 dgBilling.Columns[2].HeaderText = &quot;Description&quot;;
 dgBilling.Columns[2].DataPropertyName = &quot;matter_name&quot;;
 dgBilling.Columns[2].Width = 240;
 dgBilling.Columns[2].ReadOnly = true;
 dgBilling.Columns[3].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;

 dgBilling.Columns[3].Name = &quot;dgcTranDate&quot;;
 dgBilling.Columns[3].HeaderText = &quot;Date&quot;;
 dgBilling.Columns[3].DataPropertyName = &quot;tran_date&quot;;
 dgBilling.Columns[3].Width = 65;
 dgBilling.Columns[3].ReadOnly = true;
 dgBilling.Columns[3].DefaultCellStyle.Format = &quot;MM/dd/yy&quot;;
 dgBilling.Columns[3].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;

 dgBilling.Columns[4].Name = &quot;dgcType&quot;;
 dgBilling.Columns[4].HeaderText = &quot;Type&quot;;
 dgBilling.Columns[4].DataPropertyName = &quot;Type&quot;;
 dgBilling.Columns[4].Width = 44;
 dgBilling.Columns[4].ReadOnly = true;
 dgBilling.Columns[4].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;

 dgBilling.Columns[5].Name = &quot;dgcBillNo&quot;;
 dgBilling.Columns[5].HeaderText = &quot;Bill#&quot;;
 dgBilling.Columns[5].DataPropertyName = &quot;bill_num&quot;;
 dgBilling.Columns[5].Width = 55;
 dgBilling.Columns[5].ReadOnly = true;
 dgBilling.Columns[5].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;

 dgBilling.Columns[6].Name = &quot;dgcBillAmt&quot;;
 dgBilling.Columns[6].HeaderText = &quot;Bill Amt&quot;;
 dgBilling.Columns[6].DataPropertyName = &quot;BillAmt&quot;;
 dgBilling.Columns[6].Width = 85;
 dgBilling.Columns[6].ReadOnly = true;
 dgBilling.Columns[6].DefaultCellStyle.Format = &quot;C&quot;;
 dgBilling.Columns[6].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleRight;

 dgBilling.Columns[7].Name = &quot;dgcPmtAmt&quot;;
 dgBilling.Columns[7].HeaderText = &quot;Pmt Amt&quot;;
 dgBilling.Columns[7].DataPropertyName = &quot;PmtAmt&quot;;
 dgBilling.Columns[7].Width = 85;
 dgBilling.Columns[7].ReadOnly = true;
 dgBilling.Columns[7].DefaultCellStyle.Format = &quot;C&quot;;
 dgBilling.Columns[7].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleRight;

 dgBilling.Columns[8].Name = &quot;dgcTotalAR&quot;;
 dgBilling.Columns[8].HeaderText = &quot;A/R&quot;;
 dgBilling.Columns[8].DataPropertyName = &quot;TOTAL_AR&quot;;
 dgBilling.Columns[8].Width = 85;
 dgBilling.Columns[8].ReadOnly = true;
 dgBilling.Columns[8].DefaultCellStyle.Format = &quot;C&quot;;
 dgBilling.Columns[8].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleRight;

 dgBilling.DataSource = ds.Tables[0];

 dgBilling.Size = new System.Drawing.Size(840, 417);
 tabBilling.Size = new System.Drawing.Size(840, 417);
 tabsBillingTime.Size = new System.Drawing.Size(850, 444);

 TotalCheckBoxes = 0;
 TotalCheckedCheckBoxes = 0;
 
 //Variables for HeaderCheckBox
 TotalCheckBoxes = dgBilling.RowCount;
 TotalCheckedCheckBoxes = 0;
}
</code></pre>
 
Here is my code to clear the screen: 
 

<pre><code class="code-10 nolinks" id="code-20-41753919-3"> private void btnClear_Click(object sender, EventArgs e)
 {
 DialogResult dResult = (DialogResult)MessageBox.Show(&quot;Are you sure you want to clear search?&quot;, &quot;Clearing Searches - Start Empty Application &quot;, MessageBoxButtons.YesNo, MessageBoxIcon.Question);
 if (dResult == DialogResult.Yes)
 {
 TotalCheckBoxes = 0;
 TotalCheckedCheckBoxes = 0;
 HeaderCheckBox.CheckState = CheckState.Unchecked;
 RowCheckBoxClick((DataGridViewCheckBoxCell)dgBilling[0, 0]);

 txtSearch.Text = &quot;&quot;;
 txtSearch.ForeColor = System.Drawing.Color.Gray;
 txtSearch.Text = &quot;Search By Matter ID, Description, or Client Sort&quot;;
 txtSearch_KeyUp(sender, null);
 lblMatterCreditAmt.Text = &quot;$0.00&quot;;
 lblTrustBalanceAmt.Text = &quot;$0.00&quot;;
 lblAOL.Text = &quot;&quot;;
 lblClient.Text = &quot;&quot;;
 lblReceipts.Visible = false;
 dgReceipts.Visible = false;
 lblCreditTransfer.Visible = false;
 dgCreditTransfers.Visible = false;
 }
 }
</code></pre>
</div>

<div>
What does the code on your header checkbox that checks all the results look like?
</div>

<div>
<pre><code class="code-10 nolinks" id="code-20-41753931-1">private void HeaderCheckBox_MouseClick(object sender, MouseEventArgs e)
 {
 HeaderCheckBoxClick((CheckBox)sender);
 }


 private void HeaderCheckBoxClick(CheckBox HCheckBox)
 {
 IsHeaderCheckBoxClicked = true;

 foreach (DataGridViewRow Row in dgBilling.Rows)
 ((DataGridViewCheckBoxCell)Row.Cells[&quot;dgcChecked&quot;]).Value = HCheckBox.Checked;

 dgBilling.RefreshEdit();

 TotalCheckedCheckBoxes = HCheckBox.Checked ? TotalCheckBoxes : 0;

 GetCheckedTotals();

 IsHeaderCheckBoxClicked = false;
 }

 private void RowCheckBoxClick(DataGridViewCheckBoxCell RCheckBox)
 {
 if (RCheckBox != null)
 {
 //Modifiy Counter; 
 if (Convert.ToBoolean(RCheckBox.Value) &amp;&amp; TotalCheckedCheckBoxes &lt; TotalCheckBoxes)
 TotalCheckedCheckBoxes++;
 else if (TotalCheckedCheckBoxes &gt; 0)
 TotalCheckedCheckBoxes--;

 //Change state of the header CheckBox.
 if (TotalCheckedCheckBoxes == 0 &amp;&amp; TotalCheckBoxes == 0)
 HeaderCheckBox.Checked = false;
 else if (TotalCheckedCheckBoxes &lt; TotalCheckBoxes)
 HeaderCheckBox.Checked = false;
 else if (TotalCheckedCheckBoxes == TotalCheckBoxes)
 HeaderCheckBox.Checked = true;

 GetCheckedTotals();
 }
 }
</code></pre>
</div>

<div>
I got the code for creating and toggling the checkboxes here: 
 
<a href="http://www.codeproject.com/Articles/42437/Toggling-the-States-of-all-CheckBoxes-Inside-a-Dat" rel="ugc">http://www.codeproject.com/Articles/42437/Toggling-the-States-of-all-CheckBoxes-Inside-a-Dat</a>
</div>

<div>
Instead of calling RowCheckBoxClick() do you mean to be calling HeaderCheckBoxClick() ? &nbsp;The RowCheckBoxClick() looks like it's meant to run each time a checkbox other than the header is toggled. 
 
Also this seems to be an issue: 

<pre><code class="code-1 nolinks" id="code-20-41753981-1"> //Change state of the header CheckBox.
 if (TotalCheckedCheckBoxes == 0 &amp;&amp; TotalCheckBoxes == 0)
 HeaderCheckBox.Checked = false;
 else if (TotalCheckedCheckBoxes &lt; TotalCheckBoxes)
 HeaderCheckBox.Checked = false;
 else if (TotalCheckedCheckBoxes == TotalCheckBoxes)
 HeaderCheckBox.Checked = true;
</code></pre>
 
Because 2 of these conditions can exist at the same time. &nbsp;Can it not be? 

<pre><code class="code-1 nolinks" id="code-20-41753981-2">if (TotalCheckedCheckBoxes &lt; TotalCheckBoxes)
 HeaderCheckBox.Checked = false;
 else if (TotalCheckedCheckBoxes == TotalCheckBoxes)
 HeaderCheckBox.Checked = true;
</code></pre>
</div>

<div>
Did you mean calling HeaderCheckBoxClick() in btnClear_Click? 
 
If so I changed 
 
RowCheckBoxClick((DataGridViewCheckBoxCell)dgBilling[0, 0]); 
to &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
HeaderCheckBoxClick((CheckBox)HeaderCheckBox); 
 
And get the same results. &nbsp;The 2nd time around the header checkbox stays checked. 
 
You are correct when you say the two conditions can be the same but I if the two totals are 0 then I want HeaderCheckBox.Checked = false; &nbsp;Otherwise HeaderCheckBox.Checked = true;
</div>

<div>
My ultimate goal is to have a checkbox in the header of the checkbox column. &nbsp;I want the user to have the ability to toggle between checking/unchecking all of the checkboxes with one click. 
 
I found the code here to accomplish this. 
<a href="http://www.codeproject.com/Articles/42437/Toggling-the-States-of-all-CheckBoxes-Inside-a-Dat" rel="ugc">http://www.codeproject.com/Articles/42437/Toggling-the-States-of-all-CheckBoxes-Inside-a-Dat</a> 
 
The code works great until I need to clear the grid and the header checkbox and start over with a new number. &nbsp; I just need to make some changes but I am having trouble.
</div>

Capture.JPG

<div>
I am new to C# and datagridviews and I am having trouble taking your example of applying it to my code. &nbsp;For one I use a dataset to populate my grid. &nbsp;Would that matter?
</div>

<div>
It should not matter because a DataSet contains DataTables (which I convert my list into in order to bind it to the datagridview). &nbsp;The difference is that when I convert my list to a datatable, I add the selector column. 
 
-saige-
</div>

<div>
Unfortunately I can't figure out how to convert your code to work with how I load my datagridview. 
 
Thank you anyway.
</div>

<div>
I tested Saige's code and it works, despite the asker having issues implementing it. &nbsp;Anyone else who researches this would find the same, working answer. &nbsp;I'd recommend giving Saige 500 pts for a good thorough answer.
</div>

<div>
<div class="content wysiwyg-content">
I dynamically add a datagridview to my form. &nbsp;When a user types in a number and hits 'Enter' the datagridview is created and populated. &nbsp;I also add a checkbox in the column header so the user can toggle between checking and unchecking all of the boxes. &nbsp;My problem comes when the user clicks on the 'Clear' button. &nbsp;I would like the 'Clear' button to clear the whole grid and 'Uncheck' the column header checkbox if it is checked. &nbsp;Here is my problem: 
 

<ol type="1">
<li>I 'Check' the column Header checkbox</li>
<li>The very first time I click on the 'Clear' button the column header checkbox is unchecked</li>
<li>I 'Check the column Header checkbox a 2nd time</li>
<li>I click on the 'Clear' button a 2nd time and everything BUT the column header checkbox is cleared</li>
</ol>
 
When I step through my code it is already showing that the column header checkbox is 'Unchecked' when it is actually checked. &nbsp;It's like the state of the checkbox never gets changed. 
 
I am not sure what to do. &nbsp; 
 
Any help is appreciated.
</div>
</div>

I dynamically add a datagridview to my form.  When a user types in a number and hits 'Enter' the datagridview is created and populated.  I also add a checkbox in the column header so the user can toggle between checking and unchecking all of the boxes.  My problem comes when the user clicks on the 'Clear' button.  I would like the 'Clear' button to clear the whole grid and 'Uncheck' the column header checkbox if it is checked.  Here is my problem:

I 'Check' the column Header checkbox
The very first time I click on the 'Clear' button the column header checkbox is unchecked
I 'Check the column Header checkbox a 2nd time
I click on the 'Clear' button a 2nd time and everything BUT the column header checkbox is cleared


When I step through my code it is already showing that the column header checkbox is 'Unchecked' when it is actually checked.  It's like the state of the checkbox never gets changed.

I am not sure what to do.  

Any help is appreciated.

C# CheckState of a Checkbox

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