How to set row selection after releasing the mouse left click? - winforms

I have a datagridview. In this gridview when I left click and hold on the line and drag and drop it down to another line it is working fine but the selection of row remain same.
eg. If I select row# 2 and drag it to row# 4 , row# 2 drop at position 4 but row selection remain same. I want that when I drop it to row# 4 selected row should be row# 4.
I have done some code for drag and drop functionality.
private void dataGridView1_MouseMove(object sender, MouseEventArgs e)
{
if ((e.Button & MouseButtons.Left) == MouseButtons.Left)
{
// If the mouse moves outside the rectangle, start the drag.
if (dragBoxFromMouseDown != Rectangle.Empty &&
!dragBoxFromMouseDown.Contains(e.X, e.Y))
{
// Proceed with the drag and drop, passing in the list item.
DragDropEffects dropEffect = dataGridView1.DoDragDrop(
dataGridView1.Rows[rowIndexFromMouseDown],
DragDropEffects.Move);
}
}
}
private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
{
rowIndexFromMouseDown = dataGridView1.HitTest(e.X, e.Y).RowIndex;
if (rowIndexFromMouseDown != -1)
{
Size dragSize = SystemInformation.DragSize;
dragBoxFromMouseDown = new Rectangle(new Point(e.X - (dragSize.Width / 2),
e.Y - (dragSize.Height / 2)),
dragSize);
}
else
// Reset the rectangle if the mouse is not over an item in the ListBox.
dragBoxFromMouseDown = Rectangle.Empty;
}
private void dataGridView1_DragOver(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Move;
}
private void dataGridView1_DragDrop(object sender, DragEventArgs e)
{
Point clientPoint = dataGridView1.PointToClient(new Point(e.X, e.Y));
// Get the row index of the item the mouse is below.
rowIndexOfItemUnderMouseToDrop =
dataGridView1.HitTest(clientPoint.X, clientPoint.Y).RowIndex;
// If the drag operation was a move then remove and insert the row.
if (e.Effect== DragDropEffects.Move)
{
DataGridViewRow rowToMove = e.Data.GetData(
typeof(DataGridViewRow)) as DataGridViewRow;
dataGridView1.Rows.RemoveAt(rowIndexFromMouseDown);
dataGridView1.Rows.Insert(rowIndexOfItemUnderMouseToDrop, rowToMove);
}
}

add the lines
dataGridView1.Rows[rowIndexOfItemUnderMouseToDrop].Selected = true;
dataGridView1.Rows[rowIndexFromMouseDown].Selected = false;
at the end of dataGridView1_DragDrop so that the selection will change. you have changed the rows problematically, and that means that the selection of the dataGridView did not changed with it.

Related

Lost focus when viewModel is updated

I would like to update row of datagrid when selection is changed.
private void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
Strint rowID = ((String)((DataGrid)sender).SelectedValue);
RadekTabulky row = Client.getRadek(rowID);
if(row != null)
{
dataGrid.SelectionChanged -= DataGrid_SelectionChanged;
int index = dataGrid.SelectedIndex;
viewModel.Sumy = new SumStorage(viewModel.Soubor, viewModel.Radky);
dataGrid.SelectedIndex = index;
dataGrid.SelectionChanged += DataGrid_SelectionChanged;
}
}
I wrote this simple code. But when I click on row, the row is selected, updated but it looks like grid lost focus and I cannot see which row is selected. When I click again at same row, it will get that blue color indicating it is selected.
Is there a way how to update viewModel without losing this focus?

Using Shift key Multi selection of checkbox( Find Controls within 2 points/ rectangle

In order to select multiple checkbox within Wrap panel using Shift Key.
Capturing the Mouse down event position on Shift Keydown, on second mouse down with shift keydown, getting the 2 positions of the selection, then Need to Select the checkbox control with in the selected area.
How do I find the controls within 2 positions (System.Window.Point) or System.Windows.rect. The following code is selecting all of the checkbox within the wrappanel(lesscolorpanel).
private System.Windows.Point startPoint;
System.Windows.Point checkpPoint;
private System.Windows.Point PointWhereMouseIs;
private void LessColourPanel_OnPreviewMouseDown(object sender, MouseButtonEventArgs e)
{
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
if (startPoint == checkpPoint)
{
//GET THE MOUSE POSITION
startPoint = Mouse.GetPosition(lessColourPanel);
PointWhereMouseIs = checkpPoint;
}
else if(PointWhereMouseIs==checkpPoint)
{
//CAPTURE END MOUSE POSITION
PointWhereMouseIs = Mouse.GetPosition(lessColourPanel);
//FIND CONTROLS WIHIN RECTANGLE
Rect selareaRect = new Rect(startPoint, PointWhereMouseIs);
foreach (System.Windows.Controls.CheckBox chkitemBox in FindVisualChildren<System.Windows.Controls.CheckBox>(lessColourPanel))
{
var rectBounds = VisualTreeHelper.GetDescendantBounds(chkitemBox);
Vector vector = VisualTreeHelper.GetOffset(chkitemBox);
rectBounds.Offset(vector);
if (rectBounds.IntersectsWith(selareaRect))
{
chkitemBox.IsChecked = true;
}
}
startPoint = checkpPoint;
}
}
}
Got it, and for viewers refer Ashley Davis post
The credit goes to Ashley Davis.

Change datagrid column values in DatagridCombobox selectedindexchanged event

I have a datagrid with DatagridComboboxcolumn as one of the column in winforms.
Combobox is contain two items Y,N.
If user select Y,I need to change the value for the two columns of same row.
Same thing will happen when User select "N".
I have tried to register ComboBox_SelectedIndexChanged as follows.
But not able to get the row index or coulmn index for the selected row and change the values of the same row columns.
Please help me asap.
private void gridTesr_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
ComboBox combo = e.Control as ComboBox;
if(combo != null)
{
// Remove an existing event-handler, if present, to avoid
// adding multiple handlers when the editing control is reused.
combo.SelectedIndexChanged -=new EventHandler(ComboBox_SelectedIndexChanged);
// Add the event handler.
combo.SelectedIndexChanged +=new EventHandler(ComboBox_SelectedIndexChanged);
}
}
private void ComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
}
Try declaring your own method to handle the ComboBox.SelectedIndexChanged event.
private void gridTesr_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
ComboBox combo = e.Control as ComboBox;
if(combo != null)
{
// Remove an existing event-handler, if present
combo.SelectedIndexChanged -= this.MyComboEventHandler;
// Add the event handler
combo.SelectedIndexChanged += this.MyComboEventHandler;
}
}
private void MyComboEventHandler(object sender, EventArgs e)
{
string myValue = ((ComboBox)sender).SelectedItem.ToString();
DataGridViewCell cell = gridTesr.CurrentCell;
MessageBox.Show(string.Format("The current ComboBox resides in the Row {0} and Column {1} and it currently has the {3} value.",
cell.RowIndex, cell.ColumnIndex, myValue));
}

WPF Datagrid drag and drop questions

I have a WPF Datagrid and I'm implementing drag and drop functionality.
The datagrid has a list of "files" and the user can drag them and copy the file to the desktop.
This is done like this:
string[] files = new String[myDataGrid.SelectedItems.Count];
int ix = 0;
foreach (object nextSel in myDataGrid.SelectedItems)
{
files[ix] = ((Song)nextSel).FileLocation;
++ix;
}
string dataFormat = DataFormats.FileDrop;
DataObject dataObject = new DataObject(dataFormat, files);
DragDrop.DoDragDrop(this.myDataGrid, dataObject, DragDropEffects.Copy);
I have two questions:
1. When I want to drag multiple items- this is a problem because after I select a couple and start clicking on one to start dragging- only that gets selected and the other items get deselected. I tried the solution that is given here but for some reason it doesn't work.
2. I want to remove the dragged item from the datagrid after it is copied. The problem is that I don't know how to check if the file was copied or whether the user just dragged it on the screen without copying it.
I hope you can help me solve these problems.
Thanks!
I think this i what you are looking for:
add this code to the DataGrid__PreviewMouseLeftButtonDown event handler:
private void DataGrid_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
this.startingPosition = e.GetPosition(null);
DependencyObject dep = (DependencyObject)e.OriginalSource;
// iteratively traverse the visual tree until get a row or null
while ((dep != null) && !(dep is DataGridRow))
{
dep = VisualTreeHelper.GetParent(dep);
}
//if this is a row (item)
if (dep is DataGridRow)
{
//if the pointed item is already selected do not reselect it, so the previous multi-selection will remain
if (songListDB.SelectedItems.Contains((dep as DataGridRow).Item))
{
// now the drag will drag all selected files
e.Handled = true;
}
}
}
and now the draging won't change you selection.
Have a good luck!
I used that article to write my answer
Improved on finding the row.
Also selecting the clicked row when not dragging is added.
This now behaves exactly as other Microsoft selectors (eg Outlook)
public TreeDataGrid()
{
Loaded += TreeDataGrid_Loaded;
LoadingRow += new EventHandler<DataGridRowEventArgs>(TreeDataGrid_LoadingRow);
}
#region MultiSelect Drag
object toSelectItemOnMouseLeftButtonUp;
void TreeDataGrid_LoadingRow(object sender, DataGridRowEventArgs e)
{
e.Row.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(Row_PreviewMouseLeftButtonDown);
e.Row.PreviewMouseLeftButtonUp += new MouseButtonEventHandler(Row_PreviewMouseLeftButtonUp);
}
void Row_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
DataGridRow row = (DataGridRow)sender;
toSelectItemOnMouseLeftButtonUp = null; // always clear selecteditem
if (SelectedItems.Contains(row.Item)) //if the pointed item is already selected do not reselect it, so the previous multi-selection will remain
{
e.Handled = true; // this prevents the multiselection from disappearing, BUT datagridcell still gets the event and sets DataGrid's private member _selectionAnchor
toSelectItemOnMouseLeftButtonUp = row.Item; // store our item to select on MouseLeftButtonUp
}
}
void Row_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
DataGridRow row = (DataGridRow)sender;
if (row.Item == toSelectItemOnMouseLeftButtonUp) // check if it's set and concerning the same row
{
if (SelectedItem == toSelectItemOnMouseLeftButtonUp) SelectedItem = null; // if the item is already selected whe need to trigger a change
SelectedItem = toSelectItemOnMouseLeftButtonUp; // this will clear the multi selection, and only select the item we pressed down on
typeof(DataGrid).GetField("_selectionAnchor", BindingFlags.Instance | BindingFlags.NonPublic).SetValue(this, new DataGridCellInfo(row.Item, ColumnFromDisplayIndex(0))); // we need to set this anchor for when we select by pressing shift key
toSelectItemOnMouseLeftButtonUp = null; // handled
}
}
#endregion

moving multiple controls

I need to move a multiple textboxes with a mouse cursor.
I decided that I do it that way.
If a textbox is clicked (and Control button is pressed) textbox is added to list of selected items. Then when button is still pressed and when mouse moves I do an operation of moving controls. However my code doesn't work well. Textboxes are moving but very very fast. Here is my code
List<TextBox> items;
private void txtBox_PreviewMouseDown(object sender, RoutedEventArgs e)
{
isClicked = true;
startPoint = Mouse.GetPosition( (sender as TextBox).Parent);
items = CurrentSelection;
}
private void txtBox_PreviewMouseMove(object sender, RoutedEventArgs e)
{
Point mousePos = Mouse.GetPosition(parentCanvas);
if (isClicked)
{
foreach (TextBox item in items)
{
double left = Canvas.GetLeft(item);
double top = Canvas.GetTop(item);
Canvas.SetLeft(item, left + (startPoint.X - mousePos.X));
Canvas.SetTop(item, top + (startPoint.Y - mousePos.Y));
}
}
}
Basically I iterate through all selected items and change their position on canvas. However I probably calculate a new position in a wrong way.
The problem is, that you always calculate the delta to the initial start point. You must actualize startPoint after every call to txtBox_PreviewMouseMove. Somethin like...
private void txtBox_PreviewMouseMove(object sender, RoutedEventArgs e) {
Point mousePos = Mouse.GetPosition(parentCanvas);
if (isClicked){
foreach (TextBox item in items) {
double left = Canvas.GetLeft(item);
double top = Canvas.GetTop(item);
Canvas.SetLeft(item, left + (startPoint.X - mousePos.X));
Canvas.SetTop(item, top + (startPoint.Y - mousePos.Y));
}
startPoint=mousePoint;
}
}
...should do the job. Another thing I have seen, is that the direction is probably inverted. This can be easily corrected. Change the calculcation to...
Canvas.SetLeft(item, left + (mousePos.X-startPoint.X ));
Canvas.SetTop(item, top + (mousePos.Y-startPoint.Y));
... and this problem should also be gone.

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