Force UserControl to activate last active control

[Andrus]

I have UserControls in MDI child forms containing TextBoxes and other
controls.
When user re-activates form, I need that Control which was last activated is
activated again.
Currently *first* control is activated always.

To reproduce:

1. Run code.
2. Make TextBox2 as current TextBox by selecting its text
3. Activate other form
4. Activate previous form by clicking in form title bar

Observed:
TextBox1 receives focus

Expected:
TextBox2 should receive focus

How to force UserControl to forward focus to child its current child control
(TextBox2) ?

Andrus.


using System.Windows. Forms;
public class Test
{
static void Main()
{
Application.Run (new MainForm());
}
}

class MainForm : Form
{
public MainForm()
{
WindowState = FormWindowState .Maximized;
IsMdiContainer = true;
Form frm = new Childform();
frm.MdiParent = this;
frm.Show();
Form frm2 = new Childform();
frm2.MdiParent = this;
frm2.Show();
frm2.Left = 2000;
}
}

class Childform : Form
{
public Childform()
{
Controls.Add(ne w Mycontrols());
}
}

class Mycontrols : UserControl
{
public Mycontrols()
{
TextBox tb1 = new TextBox();
tb1.Text = "TextBox1";
TextBox tb2 = new TextBox();
Controls.Add(tb 1);
tb2.Top = 100;
tb2.Text = "TextBox2";
tb2.Select();
Controls.Add(tb 2);
}
}

[=?Utf-8?B?V2FsdGVyIEZyYW5r?=]

RE: Force UserControl to activate last active control

"Andrus" wrote:

How to force UserControl to forward focus to child its current child control
(TextBox2) ?

Hi Andrus,

remember the active control in your child form and focus it on activation:

private Control activeControl = null;

private void ChildForm_Deact ivate(object sender, EventArgs e)
{
activeControl = ActiveControl;
}

private void ChildForm_Activ ated(object sender, EventArgs e)
{
if (activeControl != null)
activeControl.F ocus();
}

you have to do the same in your UserControl!

Walter

[=?Utf-8?B?V2FsdGVyIEZyYW5r?=]

RE: Force UserControl to activate last active control

finished the example, because needed it myself:

public partial class ChildForm : Form
{
Control activeControl = null;
Control activeUserContr ol = null;

public ChildForm ()
{
InitializeCompo nent();
}

private void ChildForm _Deactivate(obj ect sender, EventArgs e)
{
activeControl = ActiveControl;
if (activeControl is IContainerContr ol)
{
activeUserContr ol =
((IContainerCon trol)activeCont rol).ActiveCont rol;
}
else activeUserContr ol = null;
}

private void ChildForm _Activated(obje ct sender, EventArgs e)
{
if (activeControl != null)
activeControl.F ocus();
if (activeUserCont rol != null)
activeUserContr ol.Focus();
}
}


Walter

[Andrus]

Re: Force UserControl to activate last active control

Walter,

finished the example, because needed it myself:

Thank you.
I tried your code with the following form:

Form contains ToolStripContai ner.
ToolStripContai ner contents panel contain UserControl and DataGridView.

For TextBox in UserControl in Activated event probably

if (activeControl != null)
activeControl.F ocus();

activates ToolStripContai ner and

if (activeUserCont rol != null)
activeUserContr ol.Focus();

activates UserControl.

In this case, this code does not set focus to proper TextBox. I tried also
to set TextBox in DataGridView as active control. It does not set focus to
DataGrdiView control also.

How to use this code with Usercontrol and DataGridView in ToolStripContai ner
?

Andrus.

[=?Utf-8?B?V2FsdGVyIEZyYW5r?=]

Re: Force UserControl to activate last active control

Hi Andrus

Form contains ToolStripContai ner.

Just change

activeControl = toolStripContai ner1.ActiveCont rol;

in ChildForm_Deact ivate event.

Walter

[=?Utf-8?B?V2FsdGVyIEZyYW5r?=]

Re: Force UserControl to activate last active control

one last more general approach:

Control activeControl = null;

private void ChildForm_Deact ivate(object sender, EventArgs e)
{
activeControl = this.ActiveCont rol;
while (activeControl is IContainerContr ol)
activeControl =
((IContainerCon trol)activeCont rol).ActiveCont rol;
}

private void ChildForm_Activ ated(object sender, EventArgs e)
{
if (activeControl != null)
activeControl.F ocus();
}

Walter

[Andrus]

Re: Force UserControl to activate last active control

Walter,

one last more general approach:

Thank you.
I tried it in the following form:

Form contains ToolStripContai ner.
ToolStripcontai ner body contains UserControl and editable DataGridView
having editmode EditOnEnter
DataGridView has DataGridViewTex tBoxColumn added in code.

When Editable TextBox in this DataGridView has focus, it is not focused on
form re-activate.
Focus() returns false for textbox.
Stepping into Focus() source code shows that this is caused probably because
TextBox does not have handle created: probably on deactivate
DataGridView releases TextBox because it has mode which creates edit control
only when column is activated.

Any ides how to fix this without changing datagridview edit modes?
Maybe we should activate grid container control first like in your first
code ?

An alternate, untested approach may be:

Control focusedControl;

public Form1()
{
InitializeCompo nent();
this.Load += new EventHandler(Fo rm1_Load);
}

void Form1_Load(obje ct sender, EventArgs e)
{
InitializeFocus Events(this);
}

private void InitializeFocus Events(Control control)
{
control.GotFocu s += new EventHandler(Co ntrol_GotFocus) ;
control.LostFoc us += new EventHandler(Co ntrol_LostFocus );
foreach (Control ctl in control.Control s)
{
InitializeFocus Events(ctl);
}
return;
}

void Control_GotFocu s(object sender, EventArgs e)
{
this.focusedCon trol = sender as Control;
}

void Control_LostFoc us(object sender, EventArgs e)
{
this.focusedCon trol = sender as Control;
}

void Form1_LostFocus (object sender, EventArgs e)
{
return;
}

void Form1_GotFocus( object sender, EventArgs e)
{
this.ActiveCont rol = this.focusedCon trol;
return;
}

Andrus.

[Andrus]

Re: Force UserControl to activate last active control

I created testcase for it:

1. Run code.
2. Enter some data to grid
3. Click other form caption
4. Click original form caption
5. Enter some characters

Observed: entered characters are ignored

Expected: entered characters must appear in last cell before form activation

How to fix ?

Andrus.

using System.Windows. Forms;

public class Test
{
static void Main()
{
Application.Run (new MainForm());
}
}

class MainForm : Form
{
public MainForm()
{
WindowState = FormWindowState .Maximized;
IsMdiContainer = true;
Form frm = new Childform();
frm.MdiParent = this;
frm.Show();
Form frm2 = new Childform();
frm2.MdiParent = this;
frm2.Show();
frm2.Left = 2000;
}
}

class Childform : Form
{
public Childform()
{
var grid = new DataGridView();
grid.Columns.Ad d(new DataGridViewTex tBoxColumn());
grid.EditMode = DataGridViewEdi tMode.EditOnEnt er;
Controls.Add(gr id);
}
}