Develop Reference

user control and raising events from controls placed in user control

So I would like to know what is wrong with the following code, especially from a theoretical point of view.
I have a user control in which I've added a text box.
When I click in the text box I would like the Mouse clicked event raised in the user control.
To my mind, the solution should be:
Create an event handler for the mouse click event in the text box.
in this event handler, raise the mouse click event for the user control.
so this is what i have:
private void txtLog_MouseClick(object sender, MouseEventArgs e)
{
this.OnMouseClick(e);
}
i have tried it and it doesn't work, why is this?
P.S. I would really like to know why this is wrong! A correct solution is great, but I'm really trying to understand where I'm going wrong here. Thank :-)

Well, you could just click on your textbox in design mode and in the property window in events tab add the click event. or if you want to do it in runtime you can do it like this:
textbox.Click += Txt_Click;
private static void Txt_Click(object sender, EventArgs e)
{
// do your thing
}
or even shorter:
textbox.Click += (s,e) =>
{
//do your thing
};

you should do these three steps
declare an MouseClick delegation method for textbox
assign method to textbox
add this delegation to the this (form) OnMouseClick event [on user control constructor]
Step1:
private void textBox1_MouseClick(object sender, MouseEventArgs e)
{
}
Step2:
this.textBox1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.textBox1_MouseClick);
Step3:
public myUserControl()
{
InitializeComponent();
this.MouseClick += new MouseEventHandler(textBox1_MouseClick);
}

how to retrieve text of buttons clicked in windows form with one single method

I have a windows form application with multiple buttons. I need to retrieve the text property of any button clicked in order to create a query to the database. the only way I know is to create a button click event and cast the sender as button then do a switch case for each button Id which seems very hectic since I probably will have more than 100 buttons in the entire application. So my question is there a generic key press method I can create which can retrieve the text property of any button pressed/clicked on the form? Please excuse me if the question is not very clear. Any help will be appreciate

Use a single click event handler for all similar kind of buttons. This way there will be click event subscribed for every button but only one method which will be executed for all buttons. You can determine which button was pressed as follows.
Using sender object as follows;
private void button_Click(object sender, EventArgs e)
{
var buttonText = ((Button)sender).Text;
//Query using buttonText
}
Update:
Above answer will still require you to subscribe click event for each button. If you don't want that then have a look at following approach;
You could use (ClickTransparentButton or) disable (Enabled=false) all these buttons and add click event on parent Form. Once you get click event you can get button which was clicked as follows;
private void Form1_Click(object sender, EventArgs e)
{
var p = PointToClient(Cursor.Position);
var control = GetChildAtPoint(p);
if(control is Button)
{
var buttonText = ((Button)control).Text;
//Query using buttonText
}
}
But this has few disadvantages such as, you will not be able to operate these buttons using keyboard.
and more...

Create some function as buttons click handler:
private void buttonClickHandler(object sender, EventArgs e)
{
string buttonName = (sender as Button).Text;
}
2A. Connect Click event of every button to this handler.
2B. To automate connection of button click handler use something like that:
private void connectButtonsHandlers()
{
foreach(var c in this.Controls)
{
if(c is Button)
{
(c as Button).Click += buttonClickHandler;
}
}
}
Add this code to form constructor to perform connection at program start.

How to determine which form was brought to front by clicking it?

I have an application with a Panel containing children Form objects. When I click one of the children Form it brings to front. I would like to know which one is in front now...
I've looked in event list but cant find proper event form my purpose :(
These methods doesn't work:
protected void OpenedFileForm_Enter(object sender, EventArgs e)
{
MessageBox.Show("enter");
}
protected void OpenedFileForm_Click(object sender, EventArgs e)
{
MessageBox.Show("click");
}
protected void OpenedFileForm_Activated(object sender, EventArgs e)
{
MessageBox.Show("activated");
}
protected void OpenedFileForm_MouseClick(object sender, MouseEventArgs e)
{
MessageBox.Show("mouse click");
}
protected void OpenedFileForm_Shown(object sender, EventArgs e)
{
MessageBox.Show("shown");
}
OpenFileDialog openFile1 = new OpenFileDialog();
openFile1.DefaultExt = "*.txt";
openFile1.Filter = "TXT Files|*.txt|RTF Files|*.rtf";
if (openFile1.ShowDialog() == System.Windows.Forms.DialogResult.OK &&
openFile1.FileName.Length > 0)
{
switch (Path.GetExtension(openFile1.FileName))
{
case ".txt":
txtForm childTXT = new txtForm();
this.childForms.Add(childTXT);
childTXT.Parent = this.mainPanel;
childTXT.richTextBox1.LoadFile(openFile1.FileName, RichTextBoxStreamType.PlainText);
childTXT.Show();
break;
}
}

Have you tried the Form.Activated Event?
http://msdn.microsoft.com/en-us/library/system.windows.forms.form.activated(v=vs.80).aspx
Edit:
If you are in an MDI application, you might need to use MdiChildActivate instead.
http://msdn.microsoft.com/en-us/library/system.windows.forms.form.mdichildactivate.aspx

This code can only work when you set the Form.TopLevel property to false. Which makes it turn into a child control, almost indistinguishable from a UserControl.
This has many side-effects, for one there is no notion of "front" anymore. The Z-order of child controls is determined by their position in their parent's Controls collection. And it affects the events it fires, Activated and Deactivated will never fire. Furthermore, the Form class was designed to be a container control, it doesn't like taking the focus itself. Its child controls get the focus, the Form class doesn't have any use for focus. Which is why the Enter, Click and MouseClick events don't fire, they are events that require focus.
Long story short, what you are trying to do doesn't make a wholeheckofalot of sense. If it is strictly the Z-order you want to fix then write an event handler for the MouseDown event:
void OpenedFileForm_MouseDown(object sender, MouseEventArgs e) {
var frm = (Form)sender;
frm.BringToFront();
}
You could add frm.Select() to get the Enter event to fire, but only do that if the form doesn't contain any focusable controls itself. Do note that there is evidence that you don't assign the events correctly in your code. The Shown event does fire. It is also important that you set the FormBorderStyle to None, the title bar cannot indicate activation status anymore.

Ok, I got this! Thx for help everyone. You gave me a hint to think about equity of my strange MDI idea where Panel is parent for other Forms. I Removed SplitContainer containing Panel and just did standard MDI application, where Forms are MDIChildren of main Form.
childTXT.MdiParent = this;

Handling an event on a dynamically-added Button after postback

Basically, I have an update panel in which i have a link button, when user clicks on the link button all the contents are cleared and textbox shows up in which user enters something and when user hit enter key, the update panel should be refreshed or gets updated or repopulated with all the contents .
How can I do it ???
The way I am trying to do this is that when event handler of link button is fired, I created a hidden button dynamically and assign it a new event handler which will get fired when user hits enter key.This new dynamic button is created inside link button event handler. In this new button event handler I will repopulate the contents back.
The problem with my way is the event handler of dynamically created button is not fired.
Why ???
Please try to answer in c#.
Thanks in advance.
Regards,
My code #
protected void Submit_Click1(object sender, EventArgs e)
{
Label1.Text = TextBox1.Text + TextBox2.Text + " are sucessfully registered";
Button mento = new Button();
mento.cssclass = "invisible";
mento.Click += new EventHandler(mento_click);
// here this new mento button is attached to update panel
updatepanel1.ContentTemplateContainer.Controls.add(mento);
}
Now the problem is mento_click event handler does not get fired ???

You can catch the enter key, in the textbox?
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
//add event keydown
textBox1.KeyDown += new KeyEventHandler(textBox1_KeyDown);
}
void textBox1_KeyDown(object sender, KeyEventArgs e)
{
switch (e.KeyCode )
{
case Keys.Enter:
//YOur updatecode here:
MessageBox.Show("You press enter");
break;
default:
break;
}
}
}

You have to attach the event on page_init or page_load every time theres a request, or the event wont get hooked up to the control.
you can check out this link to understand why:
http://msdn.microsoft.com/en-us/library/ms178472.aspx
Example
if you want to hook it up on the submit you should do something like:
page_init(object sender, EventArgs e)
{
CreateControls();
}
private void CreateControls()
{
//Create button with event and add to the panel
}
clickEvent(object sender, EventArgs e)
{
updatePanel.Update();
}
That should fire correctly the event. Im sorry i just wrote this on the fly and didnt test it, but i hope it gives you de general idea.
Cheers.

To all of you strugling with postback from buttons in asp.net, I would like to mention an alternative and ancient method of dealing with button-click events.
1) name your dynamically created buttons using a Prefix (like for instance this one: btn_). That way, every button you create will have a name starting with this prefix. For example the first button you create will have the name btn_0. You can achieve this by a routine like this one:
For _counter As Integer = 0 To 3
Dim butt As New Button
' the next 1 line is convenient when programming for the .net 4.0 framework:
butt.ClientIDMode = UI.ClientIDMode.Static
butt.butt.ID = "btn_" & _counter
butt.Text = "someting"
page.controls.add(butt)
next
2) ... and then, to handle it all, you can do it like this in the on_load event of your asp.net page:
If IsPostBack Then
For Each key As String In Request.Form
If InStr(Trim(key), "btn_") > 0 Then
Response.Write(Request.Form(key))
End If
Next
End If

How can I keep multiple controls in focus?

I have a tree view on the left side. Selecting a node displays relevant information in a form on the right side.
Would I be able to keep the tree and any one control (textbox, combobox, checkbox) on the right in focus at the same time? This will enable a user to select a field, make a change, select another node, and without having to go back and select the same field again, just type and change the value of the same field.
Thanx.
EDIT
I suppose one could implement such behaviour manually:
private Control __cFocus;
private void {anyControl}_Focus(object sender, EventArgs e)
{
__cFocus = (Control)sender;
}
private void treeView1_AfterSelect(object sender, EventArgs e)
{
__cFocus.Focus();
}
I was just wondering if there exists an automatic / more elegant solution
EDIT 2
Ok, so it seems I'll have to implement it manually. Manual implementation it is then. However, now there seem to be another problem; not sure if I should ask this as a separate question.
When selecting a node the textbox gains focus as intended, but only when using the keyboard. It doesn't work when selecting a node with the mouse. First I thought that it might be a mouse event that's interfering, but stepping revealed that the MouseUp event fired first and then the AfterSelect event which sets the focus, so I don't think it's interfering. The textbox's Enter event is also fired, but for some reason it loses focus again to the tree.
Thanx

no, you cannot keep two controls in focus at the same time. But what you can do is set the focus to the target control in the treeview AfterSelect event
private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
{
textBox1.Focus();
textBox1.SelectAll();
}
then in your textbox leave, save the changes, like so:
private void textBox1_Leave(object sender, EventArgs e)
{
//save changes here
}
this way, everytime you select an item in the treeview, check your textbox for change and save as needed, then you will refocus on the textbox for your next edit

There only can be one element having the focus!
But I have an idea for you that might solve your problem. Assuming you have a window with a TreeView and a TextBox. Set the HideSelection property of the TreeView to false and subscribe the AfterSelect event (like edeperson already answered) like this:
private void OnTreeViewAfterSelect(object sender, TreeViewEventArgs e)
{
textBox1.Text = e.Node.Text;
textBox1.Focus();
}
Then subscribe the KeyDown event of the TextBox and do following in the event method:
private void OnTextBoxKeyDown(object sender, KeyEventArgs e)
{
if ((e.KeyCode == Keys.Up) || (e.KeyCode == Keys.Down))
{
treeView1.Focus();
SendKeys.Send(e.KeyCode == Keys.Up ? "{UP}" : "{DOWN}");
}
}
At last subscribe the Leave event of the TextBox and do following in the event method:
private void OnTextBoxLeave(object sender, EventArgs e)
{
if (treeView1.SelectedNode != null)
{
treeView1.SelectedNode.Text = textBox1.Text;
}
}
And, voilá it should work like you expected it...

If you want to focus on it , you can use usercontrol. you can put your textbox on usercontrol and set focus of this textbox on usercontrol using set properties on treeview select.

No you may not, only one control may be in focus at any given time.
See Moonlight's comment for one way to achieve the behavior that you seek.