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How to regain focus in application after drag and drop to grid

In my application, I have a form with two panels. Inside one panel is a button. Inside the other is a DevExpress Grid control. The grid is made up of 3 columns. You can drag values from one column into the other to copy it.
My problem is that whenever I do a drag-and-drop from one column to another, the focus on the application goes into an unusual state. The grid remains focused; I can mouse over the headers and see them react as normal. However the rest of the application is not focused. Mouse over the button in the other panel does not react, nor do the menus or form controls. If I click on the button, it reacts like I clicked on an unfocused application. I have to click again to actually activate the button. Same for every control except the grid.
I have tried using Activate() and Focus() on the button and form but to no avail.
namespace Company.StuffUploader
{
public partial class ComputationGrid : DevExpress.XtraEditors.XtraUserControl
{
private BindingList<ComputationLinkModel> _links = new BindingList<ComputationLinkModel>();
public List<ComputationLinkModel> ComputationLinkModels
{
get
{
return new List<ComputationLinkModel>(_links);
}
}
public ComputationGrid()
{
InitializeComponent();
}
private void ComputationGrid_Load(object sender, EventArgs e)
{
_gridControl.DataSource = _links;
}
private DragDropEffects GetDragEffect(DragEventArgs e)
{
var text = e.Data.GetData("System.String") as string;
if (text == null)
return DragDropEffects.None;
var link = GetLinkFromScreenPoint(new Point(e.X, e.Y));
if (link == null)
return DragDropEffects.None;
var tokens = text.Split('\t');
if (tokens.Count() != 2)
return DragDropEffects.None;
var dateString = link.movedate.ToString("yyyy-MM-dd");
if (link.StuffSurfaceName == tokens[0] && dateString != tokens[1])
return DragDropEffects.Move;
else
return DragDropEffects.None;
}
private ComputationLinkModel GetLinkFromScreenPoint(Point screenPt)
{
var pt = _gridControl.PointToClient(screenPt);
var hitInfo = _gridView.CalcHitInfo(pt);
return _gridView.GetRow(hitInfo.RowHandle) as ComputationLinkModel;
}
private void _gridControl_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
var hitInfo = _gridView.CalcHitInfo(e.Location);
if (hitInfo == null || !hitInfo.InRowCell)
return;
// Only allow dragging from target column
if (hitInfo.Column.AbsoluteIndex != 0)
return;
var link = _gridView.GetRow(hitInfo.RowHandle) as ComputationLinkModel;
if (link == null)
return;
var item = string.Format("{0}\t{1}", link.StuffSurfaceName, link.movedate.ToString("yyyy-MM-dd"));
DoDragDrop(item, DragDropEffects.Move);
}
}
private void _gridControl_DragOver(object sender, DragEventArgs e)
{
e.Effect = GetDragEffect(e);
}
private void _gridControl_DragDrop(object sender, DragEventArgs e)
{
}
private void _gridControl_DragEnter(object sender, DragEventArgs e)
{
e.Effect = GetDragEffect(e);
}
private void _unlinkButton_Click(object sender, EventArgs e)
{
}
}
}

I figured out my own problem. Calling DoDragDrop() from within MouseDown event does not seem to work correctly. The proper way is to call it from MouseMove(). The documentation on MSDN hints at this in its example code.

Ensure that you set the DXMouseEventArgs.Handled property to true in the GridView's Mouse~ event handlers. It guarantees that default handling of these events will be prohibited. Review this example to see how to do this.

Setting up and understanding ContextMenuStrip

first of all:
I´m a student that is still learning about programming.
The problem is that when I right click in a row insde the dataGridView, the RightClickDataView.Items.Add("Abgegeben"); appears as many times as I click. How can I change this?
private void dataGridViewBestellungen_MouseDown(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Right)
{
var hti = dataGridViewBestellungen.HitTest(e.X, e.Y);
dataGridViewBestellungen.Rows[hti.RowIndex].Selected = true;
RightClickDataView.Items.Add("Abgegeben");
RightClickDataView.Show(Cursor.Position);
var xy = dataGridViewBestellungen.SelectedRows;
foreach (DataGridViewRow row in xy)
{
//take the id in the datagridview
}
RightClickDataView.ItemClicked += new ToolStripItemClickedEventHandler(rightclickmenu_ItemClicked);
// close if mouse goes away from window
}
}
private void rightclickmenu_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
{
ToolStripItem item = e.ClickedItem;
dataGridViewBestellungen.ClearSelection();
if (e.ClickedItem.Text == "Zurück")
{
//change the state to erledigt
}
}

Just remove RightClickDataView.Items.Add("Abgegeben"); from your dataGridViewBestellungen_MouseDown and place this line on your constructor for example.

Having minimum mousedown time on control

I have a control (basically an ON/OFF toggle switch) which I want the user to press for at least one second before switching states. I can measure the time between the mouse down and mouse up events on the control and make sure the mouse never leaves the control while down, but wanted to know:
Is there was a better method of establishing that the "click" on that control satisfies a minimum time?

There is no simpler way, you must do the steps you have described.
But, this "behavior" can be implemented in a general way - so it can be reused multiple times.
Here is an example of such implementation:
public class LongClick
{
public static void Attach(Control Control, EventHandler Handler)
{
var LC = new LongClick { Control = Control, Handler = Handler };
Control.MouseDown += LC.ControlOnMouseDown;
Control.MouseMove += LC.ControlOnMouseMove;
Control.MouseUp += LC.ControlOnMouseUp;
}
private Control Control;
public EventHandler Handler;
private DateTime? MDS;
private void ControlOnMouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left) MDS = DateTime.Now;
}
private void ControlOnMouseMove(object sender, MouseEventArgs e)
{
if (MDS == null) return;
if (e.X < 0) MDS = null;
if (e.X > Control.Width) MDS = null;
if (e.Y < 0) MDS = null;
if (e.Y > Control.Height) MDS = null;
}
private void ControlOnMouseUp(object sender, MouseEventArgs e)
{
if (MDS == null) return;
if (e.Button != MouseButtons.Left) return;
var TimePassed = DateTime.Now.Subtract(MDS.Value);
MDS = null;
if (TimePassed.TotalSeconds < 1) return;
if (Handler == null) return;
Handler(Control, EventArgs.Empty);
}
}
And the usage is:
private void Form1_Load(object sender, EventArgs e)
{
LongClick.Attach(button1, button1_LongClick);
}
private void button1_LongClick(object sender, EventArgs e)
{
MessageBox.Show("button1 long clicked!");
}
There are other variations of the implementation, one of them would be to override the control class (it is even simpler than this one).

C# Drag and Drop from one Picture box into Another

I'm working in visual studio 2012 with C# and I need to Drag a Picture box into another picture box, basically replace the target Picturebox Image with the Dragged Picture box image.
How do I do this?
Please be specific and try to explain as simplest and as best as possible.
I'm extremely new to programming, and a bit desperate so please be patient with me.

Drag+drop is hidden on the PictureBox control. Not sure why, it works just fine. The probable guidance here is that it will not be obvious to the user that you could drop an image on the control. You'll have to do something about that, at least set the BackColor property to a non-default value so the user can see it.
Anyhoo, you'll need to implement the MouseDown event on the first picturebox so you can click it and start dragging:
private void pictureBox1_MouseDown(object sender, MouseEventArgs e) {
var img = pictureBox1.Image;
if (img == null) return;
if (DoDragDrop(img, DragDropEffects.Move) == DragDropEffects.Move) {
pictureBox1.Image = null;
}
}
I assumed you wanted to move the image, tweak if necessary if copying was intended. Then you'll have to implement the DragEnter and DragDrop events on the second picturebox. Since the properties are hidden, you should set them in the form's constructor. Like this:
public Form1() {
InitializeComponent();
pictureBox1.MouseDown += pictureBox1_MouseDown;
pictureBox2.AllowDrop = true;
pictureBox2.DragEnter += pictureBox2_DragEnter;
pictureBox2.DragDrop += pictureBox2_DragDrop;
}
void pictureBox2_DragEnter(object sender, DragEventArgs e) {
if (e.Data.GetDataPresent(DataFormats.Bitmap))
e.Effect = DragDropEffects.Move;
}
void pictureBox2_DragDrop(object sender, DragEventArgs e) {
var bmp = (Bitmap)e.Data.GetData(DataFormats.Bitmap);
pictureBox2.Image = bmp;
}
This does allow you to drag an image from another application into the box. Let's call it a feature. Use a bool flag if you want to disallow this.

Hans's answer led me to the correct solution. The problem with that answer is that putting DoDragDrop inside MouseDown will prevent MouseClick events from firing.
Here's my solution:
private void PictureBox_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
var pb = (PictureBox)sender;
if (pb.BackgroundImage != null)
{
pb.DoDragDrop(pb, DragDropEffects.Move);
}
}
}
private void PictureBox_DragEnter (object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Move;
}
private void PictureBox_DragDrop (object sender, DragEventArgs e)
{
var target = (PictureBox)sender;
if (e.Data.GetDataPresent(typeof(PictureBox)))
{
var source = (PictureBox)e.Data.GetData(typeof(PictureBox));
if (source != target)
{
// You can swap the images out, replace the target image, etc.
SwapImages(source, target);
}
}
}
Full working example on my GitHub.

You can use mouse enter and leave events to do this easily. For example you have two picture boxes pictureBox1 and pictureBox2. And you want to drag the image from picture box1 and drop it onto picture box2 do somthing like this.
private void pictureBox2_MouseUp(object sender, MouseEventArgs e)
{
if (a == 1)
{
pictureBox1.Image = pictureBox2.Image;
a = 0;
}
}
private void pictureBox1_MouseEnter(object sender, EventArgs e)
{
a = 1;
}
Where 'a' is just a lock or key which checks whether the mouse has entered the control on which we want to drop this image on. Hope it helped, worked for me.

You can't set AllowDrop on PictureBox...set it for your whole form.
Code Snippet
Form1.AllowDrop = true;
Use the Form DragEnter, DragDrop events, they will work even if you drop it over the pictureBox.
private void Form1_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Move;
}
private void Form1_DragDrop(object sender, DragEventArgs e)
{
int x = this.PointToClient(new Point(e.X, e.Y)).X;
int y = this.PointToClient(new Point(e.X, e.Y)).Y;
if(x >= pictureBox1.Location.X && x <= pictureBox1.Location.X + pictureBox1.Width && y >= pictureBox1.Location.Y && y <= pictureBox1.Location.Y + pictureBox1.Height)
{
string[] files = (string[])e.Data.GetData(DataFormats.FileDrop);
pictureBox1.Image = Image.FromFile(files[0]);
}
}

Right click to select a row in a Datagridview and show a menu to delete it

I have few columns in my DataGridView, and there is data in my rows. I saw few solutions in here, but I can not combine them!
Simply a way to right-click on a row, it will select the whole row and show a menu with an option to delete the row and when the option selected it will delete the row.
I made few attempts but none is working and it looks messy. What should I do?

I finally solved it:
In Visual Studio, create a ContextMenuStrip with an item called "DeleteRow"
Then at the DataGridView link the ContextMenuStrip
Using the code below helped me getting it work.
this.MyDataGridView.MouseDown += new System.Windows.Forms.MouseEventHandler(this.MyDataGridView_MouseDown);
this.DeleteRow.Click += new System.EventHandler(this.DeleteRow_Click);
Here is the cool part
private void MyDataGridView_MouseDown(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Right)
{
var hti = MyDataGridView.HitTest(e.X, e.Y);
MyDataGridView.ClearSelection();
MyDataGridView.Rows[hti.RowIndex].Selected = true;
}
}
private void DeleteRow_Click(object sender, EventArgs e)
{
Int32 rowToDelete = MyDataGridView.Rows.GetFirstRow(DataGridViewElementStates.Selected);
MyDataGridView.Rows.RemoveAt(rowToDelete);
MyDataGridView.ClearSelection();
}

For completness of this question, better to use a Grid event rather than mouse.
First Set your datagrid properties:
SelectionMode to FullRowSelect
and
RowTemplate / ContextMenuStrip to a context menu.
Create the CellMouseDown event:-
private void myDatagridView_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
int rowSelected = e.RowIndex;
if (e.RowIndex != -1)
{
this.myDatagridView.ClearSelection();
this.myDatagridView.Rows[rowSelected].Selected = true;
}
// you now have the selected row with the context menu showing for the user to delete etc.
}
}

private void dgvOferty_CellContextMenuStripNeeded(object sender, DataGridViewCellContextMenuStripNeededEventArgs e)
{
dgvOferty.ClearSelection();
int rowSelected = e.RowIndex;
if (e.RowIndex != -1)
{
this.dgvOferty.Rows[rowSelected].Selected = true;
}
e.ContextMenuStrip = cmstrip;
}
TADA :D. The easiest way period. For custom cells just modify a little.

It's much more easier to add only the event for mousedown:
private void MyDataGridView_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
var hti = MyDataGridView.HitTest(e.X, e.Y);
MyDataGridView.Rows[hti.RowIndex].Selected = true;
MyDataGridView.Rows.RemoveAt(rowToDelete);
MyDataGridView.ClearSelection();
}
}
This is easier. Of cource you have to init your mousedown-event as already mentioned with:
this.MyDataGridView.MouseDown += new System.Windows.Forms.MouseEventHandler(this.MyDataGridView_MouseDown);
in your constructor.

All the answers posed in to this question are based on a mouse click event. You can also assign a ContenxtMenuStrip to your DataGridview and check if there is a row selected when the user RightMouseButtons on the DataGridView and decide whether you want to view the ContenxtMenuStrip or not. You can do so by setting the CancelEventArgs.Cancel value in the the Opening event of the ContextMenuStrip
private void MyContextMenuStrip_Opening(object sender, CancelEventArgs e)
{
//Only show ContextMenuStrip when there is 1 row selected.
if (MyDataGridView.SelectedRows.Count != 1) e.Cancel = true;
}
But if you have several context menu strips, with each containing different options, depending on the selection, I would go for a mouse-click-approach myself as well.

base on #Data-Base answer it will not work until make selection mode FullRow
MyDataGridView.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
but if you need to make it work in CellSelect Mode
MyDataGridView.SelectionMode = DataGridViewSelectionMode.CellSelect;
// for cell selection
private void MyDataGridView_MouseDown(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Right)
{
var hit = MyDataGridView.HitTest(e.X, e.Y);
MyDataGridView.ClearSelection();
// cell selection
MyDataGridView[hit.ColumnIndex,hit.RowIndex].Selected = true;
}
}
private void DeleteRow_Click(object sender, EventArgs e)
{
int rowToDelete = MyDataGridView.Rows.GetFirstRow(DataGridViewElementStates.Selected);
MyDataGridView.Rows.RemoveAt(rowToDelete);
MyDataGridView.ClearSelection();
}

private void MyDataGridView_MouseDown(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Right)
{
MyDataGridView.ClearSelection();
MyDataGridView.Rows[e.RowIndex].Selected = true;
}
}
private void DeleteRow_Click(object sender, EventArgs e)
{
Int32 rowToDelete = MyrDataGridView.Rows.GetFirstRow(DataGridViewElementStates.Selected);
MyDataGridView.Rows.RemoveAt(rowToDelete);
MyDataGridView.ClearSelection();
}

private void dataGridView1_CellContextMenuStripNeeded(object sender,
DataGridViewCellContextMenuStripNeededEventArgs e)
{
if (e.RowIndex != -1)
{
dataGridView1.ClearSelection();
this.dataGridView1.Rows[e.RowIndex].Selected = true;
e.ContextMenuStrip = contextMenuStrip1;
}
}

It is work for me without any errors:
this.dataGridView2.MouseDown += new System.Windows.Forms.MouseEventHandler(this.MyDataGridView_MouseDown);
this.dataGridView2.Click += new System.EventHandler(this.DeleteRow_Click);
And this
private void MyDataGridView_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
var hti = dataGridView2.HitTest(e.X, e.Y);
dataGridView2.ClearSelection();
dataGridView2.Rows[hti.RowIndex].Selected = true;
}
}
private void DeleteRow_Click(object sender, EventArgs e)
{
Int32 rowToDelete = dataGridView2.Rows.GetFirstRow(DataGridViewElementStates.Selected);
if (rowToDelete == -1) { }
else
{
dataGridView2.Rows.RemoveAt(rowToDelete);
dataGridView2.ClearSelection();
}
}

You can also make this a little simpler by using the following inside the event code:
private void MyDataGridView_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
rowToDelete = e.RowIndex;
MyDataGridView.Rows.RemoveAt(rowToDelete);
MyDataGridView.ClearSelection();
}
}

See here it can be done using the DataGridView RowTemplate property.
Note: This code isn't tested but I've used this method before.
// Create DataGridView
DataGridView gridView = new DataGridView();
gridView.AutoGenerateColumns = false;
gridView.Columns.Add("Col", "Col");
// Create ContextMenu and set event
ContextMenuStrip cMenu = new ContextMenuStrip();
ToolStripItem mItem = cMenu.Items.Add("Delete");
mItem.Click += (o, e) => { /* Do Something */ };
// This makes all rows added to the datagridview use the same context menu
DataGridViewRow defaultRow = new DataGridViewRow();
defaultRow.ContextMenuStrip = cMenu;
And there you go, as easy as that!

I have a new workaround to come in same result, but, with less code.
for Winforms... That's example is in portuguese
Follow up step by step
Create a contextMenuStrip in your form and create one item
Sign one event click (OnCancelarItem_Click) for this contextMenuStrip
Create a event 'UserDeletingRow' on gridview
and now... you've simulating on key press del from user
you don't forget to enable delete on the gridview, right?!
and finally...