Develop Reference

Filtering DatagridView with DateTimePicker and TextBoxes

I have a dataGridView and have logs inside it. I wanted to filter by time and number and name. There is no problem in working separately. When the textbox and datetimepicker are filtered together, I get the error that the variable of type bindingsource unable to be cast to dataview. how do i solve this problem?
I'm not printing the lines between two dates, I'm directly filtering the date written in the flight_date column. gridFilter = datagridview
private void timeFilter_ValueChanged(object sender, EventArgs e)
{
try
{
if (File.Exists(inputpath))
{
DataTable dt = (DataTable)gridFilter.DataSource;
DataView dv = new DataView();
dv = dt.DefaultView;
dv.RowFilter = "Flight_Date >= '" + timeFilter.Value.Date + "' and Flight_Date <= '" +
timeFilter.Value.Date + "'";
}
}
catch(System.InvalidCastException ex)
{
MessageBox.Show(ex.ToString());
}
}
private void txt_filterNum_TextChanged(object sender, EventArgs e)
{
if (File.Exists(inputpath))
{
BindingSource bs = new BindingSource();
bs.DataSource = gridFilter.DataSource;
bs.Filter = gridFilter.Columns[indexRoleNum].HeaderText.ToString() + " LIKE '%" + Convert.ToString(txt_filterNum.Text) + "%'";
gridFilter.DataSource = bs;
}
}

Assuming that the bind has been done correctly, i.e. a DataTable to a BindingSource to the grid, you could filter the data like this:
private void timeFilter_ValueChanged(object sender, EventArgs e)
{
SetFilter();
}
private void txt_filterNum_TextChanged(object sender, EventArgs e)
{
SetFilter();
}
private void SetFilter()
{
myBindingSource.Filter = $"Flight_Date = #{timeFilter.Value:M/dd/yyyy}# AND {gridFilter.Columns[indexRoleNum].HeaderText} LIKE '%{txt_filterNum.Text}%'";
}
As I suggested in the comments, it may provide a better experience if you implement a delay between the text changing and the filtering being done:
private void timeFilter_ValueChanged(object sender, EventArgs e)
{
SetFilter();
}
private void txt_filterNum_TextChanged(object sender, EventArgs e)
{
filterTimer.Stop();
filterTimer.Start();
}
private void filterTimer_Tick(object sender, EventArgs e)
{
filterTimer.Stop();
SetFilter();
}
private void SetFilter()
{
myBindingSource.Filter = $"Flight_Date = #{timeFilter.Value:M/dd/yyyy}# AND {gridFilter.Columns[indexRoleNum].HeaderText} LIKE '%{txt_filterNum.Text}%'";
}

How to get the selected cell value of a datagridview filled with sql data?

I need to get the value of a selected cell on a datagridview when the user clicks on it.
I've tried to bring the value to a textbox to test the click event but when I click on it, the textbox doesn't show the cell value.
private void btnsync_Click(object sender, EventArgs e) //Obtiene el catálogo de presupuestos
{
SqlConnection conn = new SqlConnection(#"Data Source=.\MYINSTANCE;Integrated Security=True;MultipleActiveResultSets=True");
string cmd = "SELECT name FROM master.dbo.sysdatabases WHERE name NOT IN ('master', 'tempdb', 'model', 'msdb');";
var dataAdapter = new SqlDataAdapter(cmd, conn);
var commandBuilder = new SqlCommandBuilder(dataAdapter);
var ds = new DataSet();
dataAdapter.Fill(ds);
dataGridView1.ReadOnly = true;
dataGridView1.DataSource = ds.Tables[0];
}
private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
if(dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value != null)
{
dataGridView1.CurrentRow.Selected = true;
txtpresup.Text = dataGridView1.Rows[e.RowIndex].Cells["name"].FormattedValue.ToString();
}
}
I expect that the "textpresup" text box is filled with the value of the selected cell.

What you're looking for is
DataGridView.SelectedRows[0].Cells[0].Value.ToString();
Don't forget to change Cells[0] to either the column index (eg Cells[4]) or the column name (eg Cells["Name"])
However, if this code is triggered and no cell/row has been selected you're likely to get a null reference error

Solved
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if (dataGridView1.SelectedCells.Count > 0)
{
int selectedrowindex = dataGridView1.SelectedCells[0].RowIndex;
DataGridViewRow selectedRow = dataGridView1.Rows[selectedrowindex];
string value = selectedRow.Cells["name"].Value.ToString();
txtpresup.Text = value;
}
}
}

Check state of combobox and change textbox readonly

I have a form that displays a datagridview and a textbox and combobox. When a column name is selected in the combobox, and a search typed in the textbox it filters and displays the searched data.
How can I detect if the combobox has nothing selected, and change the textbox readonly state to true, and when something is selected, change it back to false so I can search?
DataTable dt;
private void searchForm_Load(object sender, EventArgs e)
{
SqlCeConnection con = new SqlCeConnection(#"Data Source=|DataDirectory|\LWADataBase.sdf;");
SqlCeDataAdapter sda = new SqlCeDataAdapter("select * from customersTBL", con);
dt = new DataTable();
sda.Fill(dt);
dataGridView1.DataSource = dt;
comboSearch.Items.Add("[First Name]");
comboSearch.Items.Add("Surename");
comboSearch.Items.Add("[Address Line 1]");
comboSearch.Items.Add("[Address Line 2]");
comboSearch.Items.Add("County");
comboSearch.Items.Add("[Post Code]");
comboSearch.Items.Add("[Contact Number]");
comboSearch.Items.Add("[Email Address]");
}
private void searchTxt_TextChanged(object sender, EventArgs e)
{
{
DataView dv = new DataView(dt);
dv.RowFilter = "" + comboSearch.Text.Trim() + "like '%" + searchTxt.Text.Trim() + "%'";
dataGridView1.DataSource = dv;
}
}

You can try this
if( ComboBox.SelectedItem == null ) {
// do something
TextBox.ReadOnly = true; //Using the TextBox.ReadOnly property
}
else{
Textbox.ReadOnly=false;
}
hope it helps you!

Add a row in your FormLoad to the comboSearch control for a blank line. Make sure it's about the [First Name] item.
comboSearch.Items.Add(string.Empty);
comboSearch.Items.Add("[First Name]");
Add an event handler to comboSearch for SelectedIndexChanged. Inside the event, set the searchTxt control's ReadOnly property. It may look like this:
private void comboSearch_SelectedIndexChanged(object sender, EventArgs e)
{
searchTxt.ReadOnly = comboSearch.SelectedIndex != 0;
}

I added a SelectedIndexChanged event:
private void comboSearch_SelectedIndexChanged(object sender, EventArgs e)
{
searchTxt.ReadOnly = false;
}
And changed the TextChanged event to:
private void searchTxt_TextChanged(object sender, EventArgs e)
{
if (comboSearch.SelectedItem == null)
{
searchTxt.ReadOnly = true;
MessageBox.Show("Please select a search criteria");
}
else
{
searchTxt.ReadOnly = false;
DataView dv = new DataView(dt);
dv.RowFilter = "" + comboSearch.Text.Trim() + "like '%" + searchTxt.Text.Trim() + "%'";
dataGridView1.DataSource = dv;
}
}
and it now functions how I'd like it to

Add an empty item to the combobox and then
if(comboSearch.SelectedItem =="")
{
searchTxt.ReadOnly = true;
}
else
{
searchTxt.ReadOnly = false;
}
After executing your code add this line:
comboSearch.SelectedIndex =0;
Make sure your empty item is the first item.

Remove selected item in combobox1 from the combobox2. (Comboboxes are bound from database.)

I have 2 comboboxes named cBTeam1 and cBTeam2 (winForm & C#) both are bound from same database table.
If a person selects a team from cBTeam1, I want this selected team to not be displayed in cBTeam2.
private void bindComboBox()
{
if (con.State == ConnectionState.Closed)
{
con.Open();
}
string queryTeam1 = "SELECT * FROM Teams ORDER BY Team_name";
SqlCommand cmd = new SqlCommand(queryTeam1, con);
adapter = new SqlDataAdapter(cmd);
adapter.Fill(ds, "Teams");
this.cBoxTeam1.SelectedIndexChanged -= new EventHandler(this.cBoxTeam1_SelectedIndexChanged);
cBoxTeam1.DataSource = ds.Tables["Teams"];
//if(cBoxTeam1.SelectedIndex
cBoxTeam1.DisplayMember = "Team_name";
cBoxTeam1.SelectedIndex = -1;
cBoxTeam1.ValueMember = "team_id";
this.cBoxTeam1.SelectedIndexChanged += new EventHandler(this.cBoxTeam1_SelectedIndexChanged);
}
and here is code for cBoxTeam2 event handler cBoxTeam2_SelectedIndexChanged
private void cBoxTeam2_SelectedIndexChanged(object sender, EventArgs e)
{
if (cBoxTeam1.SelectedIndex == cBoxTeam2.SelectedIndex)
{
MessageBox.Show("You already selected " + cBoxTeam2.Text);
}
team2_id = Int32.Parse(cBoxTeam2.SelectedValue.ToString());
}
For example cBoxTeam1 displaye 3 values i.e England, India, Austrailia.
if I Select India, after selection India shold not be display in the cBoxTeam2 combobox

Hey i have made sample for you.Sample have 2 combo box and bind same data source.And when I select combobox1 firstly check with list if exist bind combobox 2 except matched item.
protected List<string> lst
{
get
{
List<string> lst =
new List<string>();
lst.Add("1");
lst.Add("2");
lst.Add("3");
return lst;
}
}
private void Form1_Load(object sender, EventArgs e)
{
comboBox1.DataSource = lst;
comboBox2.DataSource = lst;
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (lst.Contains(comboBox1.SelectedItem.ToString()))
{
comboBox2.DataSource = lst.Select(q => q.ToString(CultureInfo.InvariantCulture)).Where(q => q.ToString() != comboBox1.SelectedItem).ToList();
}
}

Try this
public void loadcBTeam1()
{
....
string queryTeam1 = "SELECT Team_name FROM Teams where Team_name <> '" + yourComboBox2.text + "' ORDER BY Team_name";
......
}
and on your ComboBox2 TextChanged
private void comboBox2_TextChanged(object sender, EventArgs e)
{
loadcBTeam1();
}

datagridview cell edit and save functionality in windows forms?

I'm working on datagridview in c# windows forms application and I'm loading the data from the database, now i want the user to be able to able to edit the cell value and save the value to the database, how to edit the cell value and how can i save the value to the database?
SqlConnection con = new SqlConnection("user id=sa;password=123;database=employee");
SqlDataAdapter da = new SqlDataAdapter("select * from UserReg", con);
DataSet ds = new DataSet();
da.Fill(ds, "p");
dataGridView1.DataSource = ds.Tables["p"];

One of the way to update a database with DataGridView is using of DataGridView's events:
DataGridView.CellBeginEdit
DataGridView.CellValidating
DataGridView.CellEndEdit
Let say: private DataGridView dgv;
Add handlers of events
dgv.CellBeginEdit += dgv_CellBeginEdit;
dgv.CellValidating += dgv_CellValidating;
dgv.CellEndEdit += dgv_CellEndEdit;
private void dgv_CellBeginEdit(Object sender, DataGridViewCellCancelEventArgs e)
{
//Here we save a current value of cell to some variable, that later we can compare with a new value
//For example using of dgv.Tag property
if(e.RowIndex >= 0 && e.ColumnIndex >= 0)
{
this.dgv.Tag = this.dgv.CurrentCell.Value;
//Or cast sender to DataGridView variable-> than this handler can be used in another datagridview
}
}
private void dgv_CellValidating(Object sender, DataGridViewCellValidatingEventArgs e)
{
//Here you can add all kind of checks for new value
//For exapmle simple compare with old value and check for be more than 0
if(this.dgv.Tag = this.dgv.CurrentCell.Value)
e.Cancel = true; //Cancel changes of current cell
//For example used Integer check
int32 iTemp;
if (Int32.TryParse(this.dgv.CurrentCell.Value, iTemp) = True && iTemp > 0)
{
//value is ok
}
else
{
e.Cancel = True;
}
}
Private Sub dgvtest1_CellEndEdit(Object sender, DataGridViewCellEventArgs e)
{
//Because CellEndEdit event occurs after CellValidating event(if not cancelled)
//Here you can update new value to database
}

Try to do this:
private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
//after you've filled your ds, on event above try something like this
try
{
da.Update(ds);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

I used OleDb but you can use SQL. Here is the code I usually use for the same.
OleDbCommand sCommand;
OleDbDataAdapter sAdapter;
OleDbCommandBuilder sBuilder;
OleDbConnection connection;
DataSet sDs;
DataTable sTable;
string myMode = "";
private void BtnLoad_Click(object sender, EventArgs e)
{
string query = "SELECT * FROM [Table]";
connection = new OleDbConnection(connectionString);
connection.Open();
sCommand = new OleDbCommand(query, connection);
sAdapter = new OleDbDataAdapter(sCommand);
sBuilder = new OleDbCommandBuilder(sAdapter);
sDs = new DataSet();
sAdapter.Fill(sDs, "Table");
sTable = sDs.Tables["Table"];
connection.Close();
DataGrid.DataSource = sTable;
DataGrid.ReadOnly = true;
DataGrid.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
}
private void BtnAdd_Click(object sender, EventArgs e)
{
DataGrid.ReadOnly = false;
myMode = "add";
}
private void BtnEdit_Click(object sender, EventArgs e)
{
DataGrid.ReadOnly = false;
myMode = "edit";
}
private void BtnDelete_Click(object sender, EventArgs e)
{
myMode = "";
if (MessageBox.Show("Do you want to delete this row ?", "Delete", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
DataGrid.Rows.RemoveAt(DataGrid.SelectedRows[0].Index);
sAdapter.Update(sTable);
}
}
private void BtnSave_Click(object sender, EventArgs e)
{
if (myMode == "add")
{
sAdapter.Update(sTable);
MessageBox.Show("Prices Are Successfully Added.", "Saved.", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);
}
else if (myMode == "edit")
{
string query = "UPDATE Table_Name SET " +
"Column1 = '" + DataGrid.SelectedRows[0].Cells[0].Value.ToString() + "' ," +
"Column2 = " + DataGrid.SelecteddRows[0].Cells[1].Value.ToString() + ", " +
"WHERE CONDITION";
connection = new OleDbConnection(connectionString);
connection.Open();
sCommand = new OleDbCommand(query, connection);
sAdapter = new OleDbDataAdapter(sCommand);
sBuilder = new OleDbCommandBuilder(sAdapter);
sDs = new DataSet();
sAdapter.Fill(sDs, "Table");
sTable = sDs.Tables["Table"];
connection.Close();
DataGrid.DataSource = sTable;
DataGrid.ReadOnly = true;
}
}

Have a look at the DataGridView Events list. You need to subscribe to the appropriate event, and handle it accordingly. Namely, you're interested in DataGridView.CellValueChanged.
dataGridView1.CellValueChanged += ValueChangedHandler;
private void ValueChangedHandler(object sender, DataGridViewCellEventArgs e) {
// do what is appropriate here.
}

Add this line of code to enable editing on datagridview
dtg.EditMode = DataGridViewEditMode.EditOnKeystroke;
Then use below event
private void dtg_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
if (e.ColumnIndex > -1 && e.RowIndex > -1)
{
dtg.ReadOnly = false;
}
}
The above two events will enable editing in datagridview.
Then use below event to save the updated data back to db.
private void dtg_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
DataGridView dgv = (DataGridView)sender;
}