I need two combo box cell in my data grid view that when we select item in first one the second binding source should be change to something
for example :
we select a bank name from the first combo box the second combo box item should be the items that belong to that bank
My binding combo box is properly working but in any event when I try to handle the changing the second datasource it have given me error like image below,
datagridview error datagridviewcomboboxcell not validate how can it be?
error datagrid view image
[1]: https://i.stack.imgur.com/u9yMO.png
DataGridView's default error handling seems to work on assumption that it cannot assume anything. So, normally it's quite safe to just override it.
myGrid.DataError += myGrid_DataError;
private void myGrid_DataError(object sender, DataGridViewDataErrorEventArgs e)
{
// ignore
}
Also gives you a place where to write actual error handling, should it become necessary.
Related
I have a simple combobox in c# forms which is populated from an array.
I have set AutoCompleteMode to SuggestAppend and AutoCompleteSource to ListItems. This allows me to filter through the list quickly by typing a string into the combobox and matching items are displayed as I type along. This works great.
However, when the drop down list is open and I start typing, the filtered list appears on top of the dropdown list but I cannot select from the filtered list but only from the drop down.
How to disable drop down list while open as soon as user enters a character into the combobox.
Currently only have one method for the combobox
private void SelectJobDropdown_SelectedIndexChanged(object sender, EventArgs e)
{
//plenty of code here
}
I have tried adding other methods for the combobox such as KeyPress or Keydown but none seems to be working for as I'm very likely doing something wrong
Using Visual Studio 2015
If I understood you correctly you don't like the overlapping list over the old drop down. Since you type letters into the ComboBox I would suggest to use the comboBox1_TextUpdate event. This nice line of code should fix your problem:
private void comboBox1_TextUpdate(object sender, EventArgs e)
{
comboBox1.DropDownStyle = ComboBoxStyle.Simple;
Setting the ComboBox.DropDownStyle property, which
specifies whether the list is always displayed or whether the list is displayed in a drop-down[...]
to ComboBoxStyle.Simple, which
Specifies that the list is always visible and that the text portion is editable. This means that the user can enter a new value and is not limited to selecting an existing value in the list.
will remove the original dropdown (long list) and only the filtered results remain.
Lets say column[0] header text equals "Jim". I need the message box to show when cell belonging to Jim's column loses focus.
private void estimateDataGridView_CellLeave(object sender, DataGridViewCellEventArgs e)
{
if (dataGridView1.CurrentRow.Cells["ColumnHeader1"].Value.ToString() == "Jim")
{
MessageBox.Show("Jim is the value of column 1");
}
}
Using the code above I get the following runtime exception:
Object reference not set to an instance of an object.
Your code is mostly right, you are just handling the wrong event (and missing a semicolon).
When CellLeave fires, the content of the cell you are leaving isn't updated yet. You want to handle CellValueChanged.
I have a DataGridView which I need to run a CellValidating event to ensure that only valid values are selected from a ComboBox. This is needed as the ComboBox contains dummy rows used to display the category, with the fields the user can select listed underneath each category.
Whilst I have the validation code working fine, there is an unwelcome side-effect that all values are being wiped from the row being validated. I have stripped the code in the Event handler down to this, and the issue still occurs:
private void dgvInformation_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)
{
DataGridView dgv = this.dgvInformation;
DataGridViewCell cell = dgv.Rows[e.RowIndex].Cells[e.ColumnIndex];
}
If I remove the
DataGridViewCell cell = dgv.Rows[e.RowIndex].Cells[e.ColumnIndex];
line then the issue does not occur.
The DGV is unbound which I believe is causing the issue. As a test I have made a simple form and populated the DGV values unbound, and each time the CellValidating event fires that row is wiped out, but when I create a List<> and use that as the DataSource the values are not wiped out. Could this be a bug with unbound DGVs?
Many thanks
I have problems with the sentense: "to ensure that only valid values are selected from a ComboBox." Using a combobox should actually prevent wrong values beeing tipped in controls like textbox, why dont you just show valid values in the combobox, or validate after all sellections have been made if you need to validate a combination of comboboxes sellection, therefor you may need somthing like a Submit button to run the validation routine.
If you still think you have to validate the combobox after each sellection then you ahve to run the validation somehow on a SelectionChanged event of the combobox.
I have a textbox and a listview. The listviewis populated based on the value entered in the textbox. Suppose I am entering any name in the textbox. As I type the name in the textbox, the results in the listview should change dynamically. For example, if I am entering John in the textbox, after entering Jo, the listview should populate the results that start with Jo and if I enter h the listview should populate the results with Joh and so on. Please suggest me a solution (in c#) for this.
Handle the "TextChanged" event of your textbox and make it run an update on your ListView given the current text.
private void txtExample_textChanged(object sender, EventArgs e)
{
UpdateListView(txtExample.Text);
}
Be wary if your search is time-expensive as the textbox will start "lagging" (missing user keystrokes) while the search is performing.
i have a check box in a datagridview windows form and have a event handler cell_Click
on cell click i check the datagridview column for a check box it shows true if the cell is selected too(that is the check box is unchecked and only the the datagrid view cell is selected) and the check box is not selected .i tried for the column gettype and found out the type it shows DatagridViewCheckBox but wrong checked values .???
If I understand you correctly you are saying the checkbox value does not align with the underlying data?
This may well be because the data has been updated and is 'dirty', e.g. it hasn't been committed to the datasource yet. If you add an event handler like this:
private void dataGridView1_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
if (dataGridView1.CurrentCell is System.Windows.Forms.DataGridViewCheckBoxCell)
{
dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
}
Then that should update the datasource and you'll have the correct checkbox state when you query the cell.
Several things here:
the cell click event just means that the user clicked with the mouse button on the data grid view, what you're looking for is probably the CellValueChanged
this event will give you the coordinates of the cell that changed. You should check to see if it's in your check box column, then get a reference to the cell and you can check the cell.Value to see if it's true or false. You're not going to find any values on the DataGridViewCheckBoxColumn -- it's going to be at the cell level, and you'll always find the value stored in cell.Value, no matter what type of column it is.