Develop Reference

WPF MouseLeftButtonDown makes FlowDocument unable to select text

I add a function that adds text to FlowDocument when the mouse clicks.
There is no Click event in FlowDocument, so I listen to FlowDocument.MouseLeftButtonDown and MouseLeftButtonUp and check whether the mouse moves between down and up. When I click the mouse left button, the text successfully adds. However, I can't select any text in the FlowDocument.
I tried PreviewMouseLeftButtonDown and PreviewMouseLeftButtonUp. The behavior is the same. Isn't there a PostMouseLeftButtonDown?
My Code:
Point mouseDownPoint;
private void doc_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
mouseDownPoint = Mouse.GetPosition(doc);
e.Handled = true;
}
private void doc_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
var mouseUpPoint = Mouse.GetPosition(doc);
if ((mouseUpPoint - mouseDownPoint).Length < 8) /* add text */;
}

The control handles the event internally.
If you register the event handler programmatically like this, your doc_MouseLeftButtonUp event handler should get invoked (note that last handledEventsToo parameter):
doc.AddHandler(ContentElement.MouseLeftButtonUpEvent,
(MouseButtonEventHandler)doc_MouseLeftButtonUp, true);
Note that you may also have to take care of the MouseLeftButtonUp that is raised by the control itself.

I found the solution. Listen to FlowDocument.MouseLeftButtonDown and do not use e.Handled=true and listen to FlowDocumentScrollViewer.PreviewMouseLeftButtonUp will get text selection and add text behavior at the same time.

Dragging over the buttons to show a word in windows form C#

I have a windows form that includes a text box and 3 buttons
The text property of the first button is C.
The text property of the second button is A
Text property of the third button is R.
Is there a way to show a car word in the text box by dragging the mouse over the previous buttons?
I tried to write the code in the MouseMove event & DragEnter event but I did not get anything.
I need to click on the first button "C" then keep pressing and dragging over the other buttons to create the word "CAR" in the textBox

You can do this using Event MouseHover
private void BtnC_MouseHover(object sender, EventArgs e)
{
TxtCar.Text += BtnC.Text;
}
private void BtnA_MouseHover(object sender, EventArgs e)
{
TxtCar.Text += BtnA.Text;
}
private void BtnR_MouseHover(object sender, EventArgs e)
{
TxtCar.Text += BtnR.Text;
}

Button mouse over ForeColour change

To create a mouse over button I use this code
private void btnCreateAccount_MouseHover(object sender, EventArgs e)
{
btnCreateAccount.ForeColor = Color.Gold;
}
private void btnCreateAccount_MouseLeave(object sender, EventArgs e)
{
btnCreateAccount.ForeColor = Color.Black;
}
The mouse over button works however when I hover over the button there is a good at least 1 second delay. I would think that it should change colour as soon as the mouse is placed over the button and not with a (in my opinion) too long delay.
Is there any way of fixing that code by like refreshing the button or something along those lines? or perhaps someone has a code that works perfectly?

You are handling the Mouse Hover event. This will require the cursor to be still for a short while in order to fire.
The pause required for this event to be raised is specified in milliseconds by the MouseHoverTime property.
This is read only.
Normally if you want the colour to change immediately you should handle the Mouse Enter event:
private void btnCreateAccount_MouseEnter(object sender, EventArgs e)
{
btnCreateAccount.ForeColor = Color.Gold;
}

Button KeyPress Not Working for Enter Key

I have a button for which I set the KeyPress event.
this.myButton.KeyPress += new KeyPressEventHandler(this.myButtonEvent_keypress);
private void myButtonEvent_keypress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Return || e.KeyChar == (char)Keys.Space)
{
// do something
}
}
Now whenever the Space key is pressed, I get the event triggered. This part works fine.
But for some reason, the Enter key press is not triggering the KeyPress
event. Also Alt, Ctrl, Shift are not working.
How can I make the button receive Enter key press?
UPDATE:
I tried below too without any luck
this.myButton.MouseClick += new MouseEventHandler(myButton_Click);

When a Button has focus and you press Enter or Space the Click event raises.
So to handle Enter or Space it's enough to handle Click event and put the logic you need there.
So you just need to use button1.Click += button1_Click;
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show("Clicked!");
}
If you really want to know if Enter or Space was pressed, you can hanlde PreviewKeyDown event:
private void button1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if(e.KeyCode== Keys.Enter)
{
MessageBox.Show("Enter");
}
if (e.KeyCode == Keys.Space)
{
MessageBox.Show("Space");
}
}

Enter and space can be handled using click event.
this.myButton.Click += new EventHandler(myButton_Click);

The Button control in WinForms will eat Enter, Space, Tab, ESC, and a few other special key's press events. One method to intercept these events is to override Control.ProcessDialogKey. Or you can override IsDialogKey to say if a key should be handled as a special case.
A another option is to set KeyPreview = true on you parent Form. Then you can handle all KeyPress events at the Form level and use Form.ActiveControl if you need to see what control has Focus

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.