I am a fairly new to Visual C# but have coded in Delphi for a long time. I have created a form that has a simple panel that is hidden unless you type in a particular key on the keyboard (I do have "KeyPreview" set for true for the form and I am using the KeyDown event to handle determining if the correct key was pressed and to make the panel visible/invisible). Just beneath the panel is a webBrowser component.
What is happening is as follows:
When my form initially starts, I have code for the "Shown" event that makes sure the form has focus initially:
private void Form1_Shown(object sender, EventArgs e)
{
if (!Focused)
{
Focus();
}
}
When the form is focused at this point, my code for detecting the proper keystroke to get the panel to appear or disappear works fine.
Here is where things get strange and I'm not sure of what to do. There are two parts I am dealing with for what is wrong:
If I click on another form and then on the caption bar of my form again to get focus on my form and try a keystroke, the keystroke detection does not work. However, if I click on another form and then back on my form one more time, the keystroke detection for the form does work. What can I do to make sure that this works each time my from has focus again?
If I click on the web browser component within my own form, the KeyDown code for the form no longer gets enacted. Even if I click on the caption bar for the form, the KeyDown event does not work. What do I need to do to assure that, if a component within my form is clicked, my form will still respond for the KeyDown event?
Thanks in advance for any advice.
I can't say why your caption bar seems to be intercepting key events. It may be that various components on the form can have focus and thus capture keyboard events. I know the web browser control works this way. You may consider capturing keyboard events globally.
I saw something on Codeproject that shows how to do this. I hope this helps.
They use UserActivityHooks.
UserActivityHook actHook;
void MainFormLoad(object sender, System.EventArgs e)
{
actHook= new UserActivityHook(); // crate an instance
// hang on events
actHook.OnMouseActivity+=new MouseEventHandler(MouseMoved);
actHook.KeyDown+=new KeyEventHandler(MyKeyDown);
actHook.KeyPress+=new KeyPressEventHandler(MyKeyPress);
actHook.KeyUp+=new KeyEventHandler(MyKeyUp);
}
As for the webbrowser control, of course it is going to interecept keyboard events. Users often have to enter text in forms and developers often code javascript on webpages to specifically hook into keyboard events. So the webbrowser control must be able to capture those.
Related
I am trying to finish my final school project. I am creating a c# winform game to be specific. We can not use anything else.
I will not be posting here code because I got it pretty messed up and I guess u can answer me just with this info.
Setup:
I got my program set up like this. The is main form and two user controls. I switch those controls within the main form during the game. The first one is MENU and the second one is GUI with picturebox acting as a gamescene.
Problem:
Setup quite not important I guess. But what I need to do is to do some action when I press key Down on the first Control (while it is active in the form). Sounds easy I thought at first but the onKeyDown event in the menu.cs(1st usercontrol) is doing nothing when i press the key(The event method is not blank). I tried this.previewKey = true; in the menu load method but it did not even recognize it.
So my question is: Is there any way to use onKeyDown in usercontrols code?
I did it this way becouse I use the same keys in the second controls and i didnt want it to get messy (which obviously did the oposite huh)
TLDR: Need to use onKeyDown event in userControls (keyPreview might be the key)
BONUS
I also need to somehow link variables from Controls 1 to Form and Controls 2.
I looked it up and found out it would be easy in situacion like "Form to Form" but since it is userControls I cant figure it out and I feel like I am just a tiny bit from finishing it.(feels terrible sitting here 9 hours xD please help)
On the keypress event make sure it is for the selected control an not the main form. If you are capturing for the form to determine which key was pressed then use the keypress event for that. You can use a messagebox to verify that you have the right control. Every key has an integer value and you can access and use those by using the properties of e.
Bonus. Depending on how you implemented your code you will have to use either global varibles to pass the data across the forms or use delegates to actively access and set controls on another form
You have to register the event in the Form.Designer.cs :
private void InitializeComponent()
{
// Your form properties here
this.KeyDown += new System.Windows.Forms.KeyEventHandler(this.Form1_KeyDown);
}
You're KeyDown event can be used like this in the Form.cs code :
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
// To know if your event is working and the value of the key who's pressed
MessageBox.Show("Key Pressed = "
+ e.KeyCode.ToString()
+ ", Value = "
+ e.KeyValue.ToString());
// Example - add some actions bellow
if (e.KeyValue == 13)
MessageBox.Show("Return Key Pressed");
}
Is there a "generic" event for a Windows Form that will trigger any time the user clicks anything on a form? I need to make sure that a certain text box has input focus at all times, so if the user clicks on a button (or anything else, for that matter), the input focus needs to be redirected to this text box.
Is there an event in the Form class that will handle this, or do I have to handle a Click event to all controls recursively on the form?
I did some digging but I can't find what I want so far.
I actually figured something out - every time the TextBox loses focus, just refocus it.
textBox.LostFocus += TextBox_LostFocus;
private void TextBox_LostFocus(object sender, EventArgs e)
{
textBox.Focus();
}
I'm fairly new to Visual Studio in C#.
I was wondering how to pop up a message box when the user clicks anywhere within the form window.
Basically, I don't want them accessing and interacting with the program unless they have a password.
Code for the Form1() is really simple right now:
public Form1()
{
InitializeComponent();
}
The actual interface has a bunch of buttons and settings (buttons and settings I don't want the user to be able to interact with unless they have verified themselves).
regarding the 1st questions.
You usually create a second model form , that is transparent and is on top of your form.
Handle the on-click event of the transparent form .
Regarding the second questions- you should rethink your design , maybe do not show the sensitive form at all untill a user has typed the password.
By the way , you have not specified what tech do you use?
is it desktop (winforms / wpf , other)/ web (web forms, asp mvc, other) ?
recommended reading for client side windows programming.
http://msdn.microsoft.com/en-us/library/dd492132.aspx
Edit:
In order to put a form on top of another form , you use a model dialog.
http://msdn.microsoft.com/en-us/library/39wcs2dh(v=vs.110).aspx
In order to create a form transparent
http://msdn.microsoft.com/en-us/library/czke9azk(v=vs.110).aspx
Also , it still depends on your UI technology.
Provided links are form winforms, other technology may require a different approach.
Edit:
As another answer pointed out , you could also bind to the original forms click event , but you will also have to bind to every child control click event recursively.
Click on form and press F4 key that show property window then click on event button there you click on click event that show in .cs file of form .
Make function like
private void Form1_Click(object sender, EventArgs e)
{
MessageBox.Show("Click");
}
I am pasting text in textbox1.text and I need textbox1 should fire its leave event by itself.
For now I am using this following code. but i will appreciate if anyone can suggest me an elegant or better way:-
private void event()
{
textbox1.Text = SearchedText;
textbox1.Focus();
textbox2.Focus();
}
First I am pasting text, then setting up Focus on the control, then set up focus again on second control. It is firing leave event of textbox1, but any thing better?
Just call the code directly, no need to wait for an event:
private void textBox1_Leave(object sender, EventArgs e) {
mumble();
}
private void someEvent() {
textBox1.Text = SearchedText;
mumble();
}
void mumble() {
// etc...
}
Just calling textBox1_Leave(this, EventArgs.Empty) works fine too.
You should handle the TextChanged or Validated events instead of the Leave event.
To FORCE Leave, Validating and so on Events, no matter what, I've found ONE working solution.
First i tried:
ProcessTabStop(true);
ProcessTabStop(false);
instead of:
textbox1.Focus();
textbox2.Focus();
Problem with the TextBox 1 and 2 Focus() is that its only Active Component that needs Leave, Validating and so on fired, not other Controls, and besides, what if the form is dynamic, you as a programmer not necessarily have any idea what Control you are trying to Leave, that's why i changed Control.Focus() method to ProcessTabStop method above. The problem is then, if only ONE Control has TabStop true, there is no control to go to and back from. So Events are NOT Fired.
Next problem is that i not necessarily Close the Form with the mouse so Focus doesn't change, I use a Key (Ctrl+Enter) to Accept the Form, and then Leave, validating and so on are NOT fired, when i Send Form Close, as Form Close registers weather there are changes or not. But Values are set in Leave on TextBoxes, so I had to find a solution that worked no matter what i did to it. I almost gave up, actually i had a problem report all filled out, when I thought, what if i set ActiveControl to Null and then to the Control it came from. It worked, but had som "Flicker" due to color change on Parent Panel depending on Active or Inactive.
The "Workaround" that works in all cases is:
Control Old = ActiveControl;
// ActiveControl.SuspendLayout();
// ActiveControl.FindForm().SuspendLayout();
ActiveControl = null;
ActiveControl = Old;
// ActiveControl.FindForm().ResumeLayout();
// ActiveControl.ResumeLayout();
That seems to fire Leave, Validating and so on Events, no matter number of Form Controls and TabStopped Controls. You MAY need to SuspendLayout on either ActiveControl, or Form. My Control (Parent Panel) changes color when Active/Inactive, if I do not Suspend Layout on Form, parent panel gets an unwanted "flicker" effect.
Looking at the solution, it is very obvious, now I've found it, but took me half a day to try different things that solved one or another problem, but not all.
I know this a VERY old thread, but one of very few articles I've found on the subject of Forcing Leave Event to be Fired.
Let's say I have internet explorer embedded in a windows form and I then navigate to a random page on the web. How can I determine when a textbox (or any other control that can accept text input for that matter) becomes the item in focus? Basically, every time the mouse is clicked I can check to see if the item in focus is a textbox or some other control for text input and then act appropriately.
Thanks in advance,
Bob
You still haven't explained the roll of the WebBrowser but the problem seems to be tracking the Input Focus. I don't know of a Form level event but you can hook an eventhandler to the Enter or GotFocus event of all relevant Controls.
// in Form_Load
foreach (var control in this.Controls) control.Enter += OnEnterControl;
private void OnEnterControl(object sender, EventArgs e)
{
focusControl = (sender as Control);
}
I believe what you want to do is sink the HTMLTextContainerEvents2 dispinterface and respond to onFocus (and potentially onBlur).
You're right that you'll have to do the interop via pinvoke yourself. I assume you can get IHTMLElement pointers to all of the objects you want to track (by using getElementsByTagName or some such thing). Once you have that,
Query the IHTMLElemnt for IConnectionPointContainer.
Call IConnectionPointContainer::FindConnectionPoint(DIID_DHTMLTextContainerEvents2)
Call IConnectionPoint::Advise() on the IConnectionPoint obtained in step 2.
And of course you need to implement IDispatch::Invoke() which will be your callback.
Handle DISPID_HTMLELEMENTEVENTS2_ONFOCUS, etc.