C# Windowsform updating dynamic generated combobox - c#

I think I am overseeing something.
I dynamically generate a few ComboBoxes with this code (I do the same for other controls like TextBox, Label etc)
private ComboBox addControlsComboBox(string Id, string TBName, int point_X, int point_Y, int SizeWidth, DataTable DT)
{
ComboBox combobox = new ComboBox();
combobox.Text = TBName;
combobox.Location = new Point(point_X, point_Y);
combobox.Size = new Size(SizeWidth, 20);
combobox.Name = Id + TBName;
combobox.DataSource = DT;
combobox.DisplayMember = "key";
combobox.ValueMember = "value";
combobox.Enabled = true;
return combobox;
}
When I automatically want to set the selected value, for the controls all the values are set correct except for the ComboBox. Not 1 comboBox is updated but all the ComboBoxes.
I use a nested dictionary object to store all the values that i need to match.
See part of the used update Code
foreach (Control gb in GroupPanel.Controls)
{
foreach (Control childc in gb.Controls)
{
if (DataCollection[GroupNames].ContainsKey(childc.Name))
{
KeyName = childc.Name;
numberLessKeyName = SL.RemoveDigits(childc.Name);
TextValue = DataCollection[GroupNames][KeyName];
switch (NumberLessKeyName)
{
case "Name":
int IntTextValue = Convert.ToInt32(TextValue);
TextValue = IntTextValue.ToString("d2");
break;
}
switch (childc.GetType().ToString())
{
case "System.Windows.Forms.TextBox":
childc.Text = TextValue;
break;
case "System.Windows.Forms.ComboBox":
// Not Working
ComboBox combobox = (ComboBox)childc;
combobox.SelectedValue = TextValue;
//Also not Working
// --> childc.Text = TextValue;
break;
case "System.Windows.Forms.CheckBox":
CheckBox chChildc = (CheckBox)childc;
if (TextValue == "Yes")
{
chChildc.Checked = true;
}
break;
};
}
}
}
What I am doing wrong?
Can somebody help me please?
[EDIT 1]
Thanks to Karol
I added The Following Lines + interface ICloneable and it worked. Many Thanks.
DataTable DT = new DataTable();
DT = DTAttribute;
DataTable DTClone = (DataTable)DT.Clone();
For those searching [C# Object Clone Wars][1] link
[EDIT 2]
A other Idea is to use COPY (works also)
DataTable DT = new DataTable();
DT = DTAttribute;
DataTable DTClone = DT.Copy();

I think You bind all ComboBox same DataTable.
You must have diffrent instance of DataTable for each ComboBox. You can do this in two ways:
- Once again SELECT data from database.
- Use deep copy to make new instance of DataTable.

Related

ComboBox added programmatically to DataGridView cell not expanding on cell click

I have a DataGridView in a C# WinForms project in which, when the user clicks on certain DGV cells, the cell changes to a DataGridViewComboBoxCell and the ComboBox is populated with some values for the user to select. Here's the form code for the DataGridView_Click event:
private void dgvCategories_Click(Object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == 5 && !(dgvCategories.Rows[e.RowIndex].Cells[e.ColumnIndex].GetType().Name == "DataGridViewComboBoxCell"))
{
// Bind combobox to dgv and than bind new values datasource to combobox
DataGridViewComboBoxCell cboNewValueList = new DataGridViewComboBoxCell();
// Get fields to build New Value query
List<string> lsNewValuesResult = new List<string>();
string strCategory = dtCategories.Rows[e.RowIndex][1].ToString();
string strCompanyName = cboSelectCompany.Text;
string strQueryGetNewValuesValidationInfo = "SELECT validationdb, validationtable, validationfield, validationfield2, validationvalue2" +
" FROM masterfiles.categories" +
" WHERE category = #category";
//" WHERE category = '" + strCategory + "'";
// Pass validation info query to db and return list of New Values
db getListOfNewValues = new db();
lsNewValuesResult = getListOfNewValues.GetNewValuesList(strQueryGetNewValuesValidationInfo, strCategory, strCompanyName);
//Populate the combobox with the list of New Values
foreach (string strListItem in lsNewValuesResult)
{
cboNewValueList.Items.Add(strListItem);
}
//
dgvCategories[e.ColumnIndex, e.RowIndex] = cboNewValueList;
}
}
Here's the code in the db class that populates the ComboBox (this likely isn't necessary to include for the purposes of this question, but for the sake of completeness, I'm including it, in case is it relevant):
public List<string> GetNewValuesList(string strValidationInfoQuery, string strCategory, string strCompanyName)
{
List<string> lsValidationInfo = new List<string>();
List<string> lsNewValuesList = new List<string>();
using (NpgsqlConnection conn = new NpgsqlConnection(connString))
using (NpgsqlCommand cmd = new NpgsqlCommand(strValidationInfoQuery, conn))
{
cmd.Parameters.AddWithValue("category", strCategory);
conn.Open();
using (NpgsqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
int intReaderIndex;
for (intReaderIndex = 0; intReaderIndex <= reader.FieldCount - 1; intReaderIndex++)
{
// reader indexes 3 & 4 correspond to categories.validationfield2 and validationvalue2, which can be null
if (string.IsNullOrEmpty(reader[intReaderIndex].ToString()))
{
lsValidationInfo.Add("");
}
else
{
lsValidationInfo.Add(reader.GetString(intReaderIndex));
}
//Console.WriteLine("reader index " + intReaderIndex + ": " + reader.GetString(intReaderIndex));
}
}
}
}
string strValidationDb = lsValidationInfo[0];
string strValidationTable = lsValidationInfo[1];
string strValidationField = lsValidationInfo[2];
string strValidationField2 = lsValidationInfo[3];
string strValidationValue2 = lsValidationInfo[4];
string strQueryGetNewValues = "SELECT DISTINCT " + strValidationField +
" FROM " + strValidationDb + "." + strValidationTable +
" WHERE company_id = (SELECT id FROM company WHERE name = '" + strCompanyName + "')";
if (!string.IsNullOrEmpty(strValidationField2) && !string.IsNullOrEmpty(strValidationValue2)) strQueryGetNewValues += " AND " + strValidationField2 + " = '" + strValidationValue2 + "'";
strQueryGetNewValues += " ORDER BY " + strValidationField;
using (NpgsqlConnection conn = new NpgsqlConnection(connString))
using (NpgsqlCommand cmd = new NpgsqlCommand(strQueryGetNewValues, conn))
{
conn.Open();
using (NpgsqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
int intReaderIndex;
for (intReaderIndex = 0; intReaderIndex <= reader.FieldCount - 1; intReaderIndex++)
{
// reader indexes 3 & 4 correspond to categories.validationfield2 and validationvalue2, which can be null
if (string.IsNullOrEmpty(reader[intReaderIndex].ToString()))
{
lsNewValuesList.Add("");
}
else
{
lsNewValuesList.Add(reader.GetString(intReaderIndex));
}
Console.WriteLine("reader index " + intReaderIndex + ": " + reader.GetString(intReaderIndex));
}
}
}
}
return lsNewValuesList;
}
The combobox is getting populated, as I can access the items in lsNewValuesResult in the _Click method. The DGV Edit Mode is set to EditOnEnter. I tried EditOnKeystroke, but that didn't cause the combobox to expand on mouse click.
This is what the combobox looks like when the cell is clicked on and the CBO is populated and added to the DGV cell:
That's after I clicked each of the two cells.
[RESOLVED]
See my Answer below.
Unfortunately solving this revealed a new issue.
I'm about to publicly admit that I'm stupid:
For design and functionality reasons that are required for this project, I am manually setting the widths and names of the DGV's columns, and I also need the 2nd through 4th columns ReadOnly = true. Well, I inadvertently set the 5th column - the column that this question is about to ReadOnly = true as well.
Thank you all for your attempts at answering. This just serves to remind us how something so simple can cause a seemingly big issue and is so easy to overlook!
If I recognize your problem correctly, in my test app i add a DataGridView whit 6 column, EditMode = EditOnEnter
(Others need three time click to open dropdown, As far as I tried) and handle CellStateChanged envent.
private void dgvCategories_CellStateChanged(object sender, DataGridViewCellStateChangedEventArgs e)
{
if (e.StateChanged == DataGridViewElementStates.Selected)
{
DataGridViewCell cell = e.Cell;
int columnIndex = cell.ColumnIndex;
int rowIndex = cell.RowIndex;
//---IF CONDITIONS--
//columnIndex == 5
// Only cells in Columns[5]
//cell.Selected
// Because this event raised two time, first for last selected cell and once again
// for currently selected cell and we need only currently selected cell.
//cell.EditType.Name != "DataGridViewComboBoxEditingControl"
// If this cell "CellStateChanged" raised for second time, only other cell types allowed
// to edit, otherwise the current cell lost last selected item.
if (columnIndex == 5 && cell.Selected && cell.EditType.Name != "DataGridViewComboBoxEditingControl")
{
DataGridViewComboBoxCell cboNewValueList = new DataGridViewComboBoxCell();
//Add items to DataGridViewComboBoxCell for test, replace it with yours.
for (int i = 0; i < 10; i++)
cboNewValueList.Items.Add($"Item {i}");
dgvCategories[columnIndex, rowIndex] = cboNewValueList;
}
}
}
NOTE: user must click two time in a cell to open drop down menu.
Edit One: As Reza Aghaei suggest for single click in cell:
private void dgvCategories_CellClick(object sender, DataGridViewCellEventArgs e)
{
DataGridViewComboBoxEditingControl editingControl = dgvCategories.EditingControl as DataGridViewComboBoxEditingControl;
if (editingControl != null)
editingControl.DroppedDown = true;
}
You might need to turn AutoGenerateColumns off:
Also, it seems to take a three clicks for the dropdown to pop.
public Form1()
{
InitializeComponent();
dataGridView1.AutoGenerateColumns = false;
dataGridView1.DataSource = GetDataSource();
DataGridViewComboBoxColumn dgvcbc = new DataGridViewComboBoxColumn();
dgvcbc.Items.Add("R0C0");
dgvcbc.Items.Add("R1C0");
dgvcbc.Items.Add("R2C0");
dgvcbc.Items.Add("R3C0");
dgvcbc.DataPropertyName = "Col0";
dataGridView1.Columns.Add(dgvcbc);
}
DataTable GetDataSource()
{
var dtb = new DataTable();
dtb.Columns.Add("Col0", typeof(string));
dtb.Columns.Add("Col1", typeof(string));
dtb.Columns.Add("Col2", typeof(string));
dtb.Columns.Add("Col3", typeof(string));
dtb.Columns.Add("Col4", typeof(string));
dtb.Rows.Add("R0C0", "R0C1", "R0C2", "R0C3", "R0C4");
dtb.Rows.Add("R1C0", "R1C1", "R1C2", "R1C3", "R1C4");
dtb.Rows.Add("R2C0", "R2C1", "R2C2", "R2C3", "R2C4");
dtb.Rows.Add("R3C0", "R3C1", "R3C2", "R3C3", "R3C4");
return dtb;
}
Are you maybe getting an error which is not being shown for some reason?
If I use your code, DataGridViewComboBoxCell seems to be populated with values, but I get DataGridViewComboBoxCell value is not valid runtime error.
This test code is working fine for me:
private void dgvCategories_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
DataGridViewComboBoxCell cboNewValueList = new DataGridViewComboBoxCell();
List<string> lsNewValuesResult = new List<string>();
lsNewValuesResult.Add("Value1");
lsNewValuesResult.Add("Value2");
lsNewValuesResult.Add("Value3");
foreach (string strListItem in lsNewValuesResult)
{
cboNewValueList.Items.Add(strListItem);
}
dgvCategories[e.ColumnIndex, e.RowIndex] = cboNewValueList;
// Added setting of initial value
cboNewValueList.Value = cboNewValueList.Items[0];
}
So maybe try setting the initial value for your DataGridViewComboBoxCell after you add it to the DataGridView.
You can consider the following facts about DataGridView:
If you set AutoGenerateColumns to false, then you need to add columns to Columns collection manually.
If you set AutoGenerateColumns to true, when you assign the data to DataSource, the control generates columns automatically for the data source. In this case, the control looks in list of columns of the data source and for each column if there's no column in the Columns collection of the control having the same DataPropertyName as data source's column name, it will add a column to Columns collection.
DataPropertyName of the datagridviews' columns determines the bound column of the data source.
You usually want to add DataGridViewXXXXColumn to columns collection rather than using a DataGridViewXXXXCell for a cell.
If you set EditMode to EditOnEnter, then if you click on dropdown button, one click is enough. If you click on cell content, two clicks is needed.
If you would like to make it single click even if you click on cell content, take a look at this post. (Note: I haven't used this is the example, it's a bit annoying.)
you can set DisplayStyle to Nothing, then it shows the column as a combo box, just in edit mode.
A basic example on using DataGridViewComboBoxColumn
I suppose you are going to show a list of Products having (Id, Name, Price, CategoryId) in a DataGridView and the CategoryId should come from a list of Categories having (Id, Name) and you are going to show CategoryId as a ComboBox.
In fact it's a basic and classic example of DataGridViewComboBoxColumn:
private void Form1_Load(object sender, EventArgs e) {
var categories = GetCategories();
var products = GetProducts();
var idColumn = new DataGridViewTextBoxColumn() {
Name = "Id", HeaderText = "Id", DataPropertyName = "Id"
};
var nameColumn = new DataGridViewTextBoxColumn() {
Name = "Name", HeaderText = "Name", DataPropertyName = "Name"
};
var priceColumn = new DataGridViewTextBoxColumn() {
Name = "Price", HeaderText = "Price", DataPropertyName = "Price"
};
var categoryIdColumn = new DataGridViewComboBoxColumn() {
Name = "CategoryId", HeaderText = "Category Id", DataPropertyName = "CategoryId",
DataSource = categories, DisplayMember = "Name", ValueMember = "Id",
DisplayStyle = DataGridViewComboBoxDisplayStyle.Nothing
};
dataGridView1.Columns.AddRange(idColumn, nameColumn, priceColumn, categoryIdColumn);
dataGridView1.EditMode = DataGridViewEditMode.EditOnEnter;
dataGridView1.AutoGenerateColumns = false;
dataGridView1.DataSource = products;
}
public DataTable GetProducts() {
var products = new DataTable();
products.Columns.Add("Id", typeof(int));
products.Columns.Add("Name", typeof(string));
products.Columns.Add("Price", typeof(int));
products.Columns.Add("CategoryId", typeof(int));
products.Rows.Add(1, "Product 1", 100, 1);
products.Rows.Add(2, "Product 2", 200, 2);
return products;
}
public DataTable GetCategories() {
var categories = new DataTable();
categories.Columns.Add("Id", typeof(int));
categories.Columns.Add("Name", typeof(string));
categories.Rows.Add(1, "Category 1");
categories.Rows.Add(2, "Category 2");
return categories;
}
Learn more
To learn more about DataGridView, take a look at DataGridView Control (Windows Forms). It contains links to some documentations and useful How To articles, including:
DataGridView Control Overview
Basic Column, Row, and Cell Features in the Windows Forms DataGridView Control
Basic Formatting and Styling in the Windows Forms DataGridView Control
Column Types in the Windows Forms DataGridView Control

How to get value of a programmatically written combobox in a datagrid in wpf?

To follow my previous post here => Binding SelectedItem of ComboBox in DataGrid with different type
I have now a datagrid containing 2 columns, one with a text, the other with a combobox (in a datatemplate, written thru the C# code, not the Xaml).
After having done some choice on the combobox, I now would like to parse the result but the value of the cell containing my combobox stay empty :
foreach(DataRowView row in Datagrid1.Items)
{
var firstColumNresult = row.Row.ItemArray[0];// Return correctly a string
var myrow = row.Row.ItemArray[1];// always empty...
}
The result is that I cant get the values of my (previously generated) combobox.
I suppose one binding must missed somewhere...
This is the combobox creation code :
DataTable tableForDG = new DataTable();
tableForDG.Columns.Add(new DataColumn { ColumnName = "Name", Caption = "Name" });
tableForDG.Columns.Add(new DataColumn { ColumnName = "Attachment", Caption = "Attachment" }); // this column will be replaced
tableForDG.Columns.Add(new DataColumn { ColumnName = "AttachmentValue", Caption = "AttachmentValue" });
tableForDG.Columns.Add(new DataColumn { ColumnName = "DisplayCombo", Caption = "DisplayCombo", DataType=bool });
// Populate dataview
DataView myDataview = new DataView(tableForDG);
foreach (var value in listResults)// a list of string
{
DataRowView drv = myDataview.AddNew();
drv["Name"] = value.Name;
drv["Attachment"] = value.Name;// this column will be replaced...
drv["DisplayCombo"] = true;// but it can be false on my code...
}
var DG = myDataview;//
Datagrid1.ItemsSource = DG;
Datagrid1.AutoGenerateColumns = true;
Datagrid1.Items.Refresh();
DataGridTemplateColumn dgTemplateColumn = new DataGridTemplateColumn();
dgTemplateColumn.Header = "Attachment";
var newCombobox = new FrameworkElementFactory(typeof(ComboBox));
newCombobox.SetValue(ComboBox.NameProperty, "myCBB");
Binding enableBinding = new Binding();
newCombobox.SetValue(ComboBox.IsEnabledProperty, new Binding("DisplayCombo"));
newCombobox.SetValue(ComboBox.SelectedValueProperty, new Binding("AttachmentValue"));
List<string> listUnitAlreadyAttached = new List<string>();
// fill the list...
enableBinding.Source = listUnitAlreadyAttached;
newCombobox.SetBinding(ComboBox.ItemsSourceProperty, enableBinding);
var dataTplT = new DataTemplate();
dataTplT.VisualTree = newCombobox;
dgTemplateColumn.CellTemplate = dataTplT;
Datagrid1.Columns[1] = dgTemplateColumn;
Any idea/advice ?
You should explicitely specify the binding mode and update trigger of your binding. Also use SetBinding instead of SetValue:
var valueBinding = new Binding("AttachmentValue")
{
Mode = BindingMode.TwoWay,
UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
};
newCombobox.SetBinding(ComboBox.SelectedValueProperty, valueBinding);
This should enable you to get the selected value into your row data. It might not update in the displayed datagrid value for the AttachmentValue column.

Devexpress, RepositoryItemComboBox with multiple columns like RepositoryItemGridLookUpEdit

I want to display grid with multiple columns (like in RepositoryItemGridLookUpEdit) after click on cell in column, but if user don't want to pick item from grid, he can write something else (like in RepositoryItemComboBox). How to combine this two features?
//user can write, but only one column
RepositoryItemComboBox cbeMaterialy = new RepositoryItemComboBox();
DataTable dt = Getdt();
cbeMaterialy.Items.Clear();
foreach(DataRow item in dt.Rows)
{
cbeMaterialy.Items.Add(item);
}
gvView.Columns["ColumnName"].ColumnEdit = cbeMaterialy;
//user cannot write but multiple columns
RepositoryItemGridLookUpEdit editor = new RepositoryItemGridLookUpEdit();
editor.DataSource = dt;
column.ColumnEdit = editor;
//SOLUTION!
I mixed some answer from Devexpress team and came up with this:
public class Main()
{
//user can choose element from DB or write new value
RepositoryItemGridLookUpEdit riglue = new RepositoryItemGridLookUpEdit();
MyGridLookupDataSourceHelper.SetupGridLookUpEdit(riglue, GetMaterialyDataView(), "Kod", "Kod");
elementsEditGrid.gvView.Columns[ColumnName].ColumnEdit = riglue;
}
///////////////////
public class MyGridLookupDataSourceHelper
{
RepositoryItemGridLookUpEdit edit;
public MyGridLookupDataSourceHelper(RepositoryItemGridLookUpEdit edit, ITypedList dataSource, string displayMember, string valueMember)
{
this.edit = edit;
//enable writing into RepositoryItemGridLookUpEdit
edit.TextEditStyle = DevExpress.XtraEditors.Controls.TextEditStyles.Standard;
edit.DataSource = dataSource;
edit.DisplayMember = displayMember;
edit.ValueMember = valueMember;
edit.ProcessNewValue += edit_ProcessNewValue;
AddExistingValuesToDataSource();
}
public static void SetupGridLookUpEdit(RepositoryItemGridLookUpEdit edit, ITypedList dataSource, string displayMember, string valueMember)
{
new MyGridLookupDataSourceHelper(edit, dataSource, displayMember, valueMember);
}
//Add new values to temporary data source (not to DataBase!)
void edit_ProcessNewValue(object sender, DevExpress.XtraEditors.Controls.ProcessNewValueEventArgs e)
{
GridLookUpEdit lookUp = sender as GridLookUpEdit;
RepositoryItemGridLookUpEdit ri = lookUp.Properties;
DataTable dt = (ri.DataSource as DataView).Table;
DataRow row = dt.NewRow();
row[ri.DisplayMember] = e.DisplayValue;
row[ri.ValueMember] = e.DisplayValue;
dt.Rows.Add(row);
ri.View.RefreshData();
e.Handled = true;
//if user wants to add new values to database (data source)
//INSERT INTO DataSourceTable (ColumnName) VALUES (e.DisplayValue)
}
//Adds to temporary data source values already stored in RepositoryItemGridLookUpEdit (in case values aren't from DB)
void ProcessExistingValues(RepositoryItemGridLookUpEdit sender, object value)
{
RepositoryItemGridLookUpEdit ri = sender;
DataTable dt = (ri.DataSource as DataView).Table;
DataRow row = dt.NewRow();
row[ri.DisplayMember] = value;
row[ri.ValueMember] = value;
dt.Rows.Add(row);
ri.View.RefreshData();
}
private void AddExistingValuesToDataSource()
{
//SELECT from DB values that are already in riglue and add them to TEMPORARY DATA SOURCE (in case values aren't from DB)
//DataView dataView = SELECT ColumnName FROM table WHERE rowID = XXX
foreach (DataRow row in dataView.AsEnumerable())
{
string kod = (string)row["ColumnName"];
ProcessExistingValues(this.edit, kod);
}
}
}
You can set the RepositoryItemGridLookUpEdit.TextEditStyle property to Standard and you will be able to type. When a user types something different from what is contained in the lookup data source, the RepositoryItemGridLookUpEdit.ProcessNewValue event will be raised. In the event handler, you can add a new value to the data source to use it further.
RepositoryItemComboBox doesn't has DataSourse property, which allow to bind table with multiple column.
ComboBoxEdit Has DataSourse property, So you can bnd table with multiple column, OR create multiple column.

How to set a DataGridView column to a DataGridViewComboBoxColumn?

Here is my code:
DataSet data = new DataSet();
data.ReadXml("data.xml");
DataGridView grid = new DataGridView();
var genreCboBoxItems = data.Tables[0].AsEnumerable().Select(genre => genre.Field<string>("genre")).Distinct().ToArray();
// TODO: Make is so the 'genre' column in grid is a combo box?
grid.DataSource = data.Tables[0];
grid.Dock = DockStyle.Fill;
this.Controls.Add(grid);
*edit: genreCboBoxItems
Try this: (not tested)
var column = new DataGridViewComboBoxColumn();
column.DataSource = data.Tables[0].AsEnumerable().
Select(genre => new { genre = genre.Field<string>("genre") }).Distinct();
column.DataPropertyName = "genre";
column.DisplayMember = "genre";
column.ValueMember = "genre";
grid.DataSource = data.Tables[0];
// Instead of the below line, You could use grid.Columns["genre"].Visible = false;
grid.Columns.Remove("genre");
grid.Columns.Add(column);
This might help you cast DataGridViewColumn to DataGridViewComboBox.
First create DataGridViewComboBoxColumn using designer with proper name. Then say you have a list of String list and other string values to bind to that datagridview then use this code:
Below code will bind a list to two DataGridViewTextBoxCell and a DataGridViewComboBoxCell. Note AllCriterias is a list with two string values and a list of string. DGVEligibilityCriteria is the grid name.
for (int i = 0; i < AllCriterias.Count; i++)
{
DataGridViewTextBoxCell Cmb1 = (DataGridViewTextBoxCell)DGVEligibilityCriteria.Rows[i].Cells[0];
Cmb1.Value = AllCriterias[i].Name;
DataGridViewTextBoxCell Cmb2 = (DataGridViewTextBoxCell)DGVEligibilityCriteria.Rows[i].Cells[1];
Cmb2.Value = AllCriterias[i].Type;
DataGridViewComboBoxCell Cmb = (DataGridViewComboBoxCell)DGVEligibilityCriteria.Rows[i].Cells[2];
foreach (var filtervalue in AllCriterias[i].FilterValues)
{
Cmb.Items.Add(filtervalue);
}
}
Need to display the fist index as default by setting selectindex property.
Use this code : Here "filterValues" is the name of the DataGridViewComboBoxCell which u created in the datagridview designer.
foreach (DataGridViewRow row in DGVEligibilityCriteria.Rows)
{
row.Cells["filterValues"].Value = (row.Cells["filterValues"] as DataGridViewComboBoxCell).Items[0];
}

How to sort DataGridView when bound to a binding source that is linked to an EF4 Entity

I have a DataGridView that is linked to a BindingSource.
My BindingSource is linked to an IQueryable list of entities:
public void BindTo(IQueryable elements)
{
BindingSource source = new BindingSource();
source.DataSource = elements;
bindingNavigator1.BindingSource = source;
dataGridView1.DataSource = source;
}
I am wanting my users to be able to click on the grid headers to sort the data - struggling to get this to work. Is it possible? If so, how do I do it?
I recently struggled with this same issue; it seems that the IQueryable interface doesn't provide enough information for the DataViewGrid to know how to sort the data automatically; so you have to either repackage your collection from the Entity source using something it can use or do what I did and handle the sorting functionality manually:
private void myDataGridView_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
DataGridViewColumn column = myDataGridView.Columns[e.ColumnIndex];
_isSortAscending = (_sortColumn == null || _isSortAscending == false);
string direction = _isSortAscending ? "ASC" : "DESC";
myBindingSource.DataSource = _context.MyEntities.OrderBy(
string.Format("it.{0} {1}", column.DataPropertyName, direction)).ToList();
if (_sortColumn != null) _sortColumn.HeaderCell.SortGlyphDirection = SortOrder.None;
column.HeaderCell.SortGlyphDirection = _isSortAscending ? SortOrder.Ascending : SortOrder.Descending;
_sortColumn = column;
}
I hope that helps.
VB.NET
If you are using a bindingsource with linq syntax you can sort your data like this
In this case When loading a bindningsource associated with a datagridview from entity framwork objects "NCFile" with having a foreign column to a list of "NCFilePartSet "
bsFileSections.DataSource = From ncfps In NCFile.NCFilePartSet Order By ncfps.Sort Select ncfps
or like this
bsFileSections.DataSource = NCFile.NCFilePartSet.OrderBy(Function(ncfps) ncfps.Sort)
where "Sort" is a column in NCFilePartSet
Updates on entities continue working and reflects back to the database
Yes, it is possible to easily have a sortable DGV when bound to EF data. Use the BindingListView from the BLW library (also, check out How do I implement automatic sorting of DataGridView?).
public void BindTo(IQueryable elements)
{
BindingSource source = new BindingSource();
source.DataSource = new BindingListView(elements.ToList());
bindingNavigator1.BindingSource = source;
dataGridView1.DataSource = source;
}
In my tests, even when .ToList() was called within the constructor (as above), changes were propagated to the DB, which surprised me.
This code snippet works very well, and fast enough for most purposes...
int iColNumber = 3; //e.g., sorting on the 3rd column of the DGV
MyBindingSource.DataSource = MyBindingList.OrderByDescending(o => o.GetType().GetProperty(MyDataGridView.Columns[iColNumber].Name).GetValue(o));
I suggest you to dynamically convert entities into data table. There is a method
public static DataTable GetTableFromList<T>(IEnumerable<T> list)
{
DataTable dt = new DataTable();
PropertyInfo[] properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
foreach (PropertyInfo property in properties)
dt.Columns.Add(property.Name, property.PropertyType);
foreach (T item in list)
{
DataRow newRow = dt.NewRow();
foreach (PropertyInfo property in properties)
{
newRow[property.Name] = property.GetValue(item);
}
dt.Rows.Add(newRow);
}
return dt;
}
After conversion pass table into bindingsource
source.DataSource = GetTableFromList<T>(elements);
Be aware of property types that cannot be converted into a column types.
maybe this will help you.
internal class CustomDataGridView : DataGridView
{
public SortOrder MySortOrder { get; set; }
protected override void OnColumnHeaderMouseClick(DataGridViewCellMouseEventArgs e)
{
BindingSource MyBindingSource = (BindingSource)base.DataSource;
DataTable MyDataTable = (DataTable)MyBindingSource.DataSource;
switch (MySortOrder)
{
case SortOrder.None:
MyDataTable.DefaultView.Sort = base.Columns[e.ColumnIndex].Name + " ASC";
MyDataTable = MyDataTable.DefaultView.ToTable();
MyBindingSource.DataSource = MyDataTable;
MySortOrder = SortOrder.Ascending;
break;
case SortOrder.Ascending:
MyDataTable.DefaultView.Sort = base.Columns[e.ColumnIndex].Name + " DESC";
MyDataTable = MyDataTable.DefaultView.ToTable();
MyBindingSource.DataSource = MyDataTable;
MySortOrder = SortOrder.Descending;
break;
case SortOrder.Descending:
MyDataTable.DefaultView.Sort = Properties.Settings.Default.OderDataGridView; //SqlOriginOrder
MyDataTable = MyDataTable.DefaultView.ToTable();
MyBindingSource.DataSource = MyDataTable;
MySortOrder = SortOrder.None;
break;
}
base.Columns[e.ColumnIndex].HeaderCell.SortGlyphDirection = MySortOrder; //mini arrow
}
}

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