If I have a project and I do not how design corresponds to the code is there a way to make the debugger break every time I press any button so I can quickly navigate to the right place in the code or am I asking for too much here?
You can make a call to System.Diagnostics.Debugger.Break() to tell any attached debuggers to break at that line.
If none are attached, Windows will try to launch any registered debuggers. If not are registered, you'll get an exception/crash of the application. So, don't leave it in the code in production :)
e.g. (as per icemanind's comment)
#if DEBUG
Debugger.Break();
#endif
If you want to break on a click of any button, it gets a bit tricky. The easiest thing is to write a Button wrapper class and override OnClick and put your Break call in there. For example:
public class ButtonWedge : Button
{
protected override void OnClick(System.EventArgs e)
{
Debugger.Break();
base.OnClick(e);
}
}
Once you add that class you can drag and drop it on the design surface. But, if you've already got code, you can edit the designer.cs file and replace System.Windows.Forms.Button with ButtonWedge.
Once in OnClick, you can see where the Click event will go by looking at the base classes Events array with the Control.EventClick key. That will contain a multicast delegate that you can look at the Method and Target properties to find out what has subscribed to this Click event. In other words, the name of the click handler at runtime will be:
string handlerName = base.Events[Control.EventClick].Target.GetType().FullName + '.'
+ base.Events[Control.EventClick].Method.Name;
It doesn't really put a break point in a particular Click event but lets you know what's going on and where...
If you meant a button on the program in the project then use Peter's answer. If you were asking can you make a button on the keyboard or mouse cause execution to break or pause, you can press Ctrl+Alt+Pause.
Why you cannot just DoubleClick on the button in design mode. Its open in code right on the function that handles a click event.
Related
Please help me to fix this problem in c#. Every time i accidentally click any Button,Text Box etc. it will go to the source code and when i delete the code, debug wont run, but when i put comment sign /* comment*/ the application will run.
Any one can help me on how to remove on click event.
this is what i want to remove
private void comboBox3_SelectedIndexChanged(object sender, EventArgs e)
{ }
Every time i delete this debug will prompt me. but when i using VB i can easily delete this no need to remove the button or txtbox etc.
Basically when you double click a control, the designer automatically create a the event handler.
It also automatically assigns the event handler to the control. It makes this change in the designer.cs file of your form. This is handeled for you.
Unfortunately, when you remove the code you pointed out, the function no longer exists. Therefore, the solutions fails to build because the reference to the function still exist in the. Designer.cs file.
You need to remove the reference in the designer.cs file:
"If you click on a control in the Form Designer, you see a list of event handlers that the designer is associating with the control in the Properties Window. Click on the lightning bolt at the top of the Window to see a listing of events. You will see method names next to events that the Form Designer is writing code for in the designer.cs file. Simply erase the name of the method for the event you wish to disconnect, hit Enter, done."
- https://social.msdn.microsoft.com/Forums/vstudio/en-US/a6f25488-b761-437f-8a65-e7e51dd4b382/remove-event-handler?forum=csharpgeneral
You would not have to do this in VB.net, as VB.net uses the handles command whereas c# performs a method like so:
button1.Click += new EventHandler(button1_Click);
Just simply remove the event from your element before deleting the method in your code:
There will be a line in form.designer.cs class just remove that.
comboBox3.SelectedIndexChanged+=new eventargs(comboBox3_SelectedIndexChanged);
Moreover, windows forms use CodDom to write a code to you have to be careful hope this will help you to learn more about creating windows form application.
https://learn.microsoft.com/en-us/dotnet/framework/winforms/controls/how-to-add-controls-to-windows-forms
I am new to Visual Studio and C#. I have created my first project -- an inventory application using MySql -- and everything works. But I needed to add a new button to the form for deleting records, so I dragged it in from the toolbox, changed the text ("Delete Product") and changed the design name ("DelBtn"). Adding the tool did not create the event handler, so I added the following with the MessageBox for testing:
private void DelBtn_Click(object sender, EventArgs e)
{
MessageBox.Show("Delete button clicked");
}
Clicking the button, however, has no effect, no MessageBox or anything else. Can someone help, please?
Go to your form designer, right-click your button, and select "Properties". In the properties window, there will be an "Events" button (it looks like a lightning bolt). Click that, and look for the Click event of your button. Make sure that DelBtn_Click is listed there. At that point, the button should respond with your code.
Hope this helps!
You need to make sure you've wired up the handler correctly. Look for the designer file that gets generated along with your form (I'm making the assumption that this is winforms).
Then you'll need a line like this in your InitializeComponent method:
this.button1.Click += new System.EventHandler(this.DelBtn_Click);
You don't have to do this in your designer file, you can do it anywhere you want that runs before your form is shown, e.g. the constructor. But it seems to me like something you did -- maybe by manually-renaming your event handler method -- has mangled the automatically-generated designer code that I mentioned above, and you probably just need to fix what's there already.
You need to delegate the event in your designer.cs if you wish:
DelBtn.Click += new System.EventHandler(this.DelBtn_Click);
Just adding a method with the same name as VS would have made for you won't bind the event to that method. Open the properties for the button and at the top of the resulting panel you'll see a lightning bolt. Click that and find the event you want and type in your method name there.
You need to go on the form, click on the button, on the properties menu you need to click on event,find onclick and double click the blank space.
It will automatically create the onclick method for you.
I have a button with an event handler attached to it; 2-clicking it in the designer takes me to the code. Nowhere is the handler being unhooked/detached.
Some code I expected to run apparently isn't, so I put a bunch of MessageBox.Show()s in the handler, even at the very beginning, but none of them display (Note: I can't step through the code; I have to do it this way (arggghhhh)).
Here's some of the code:
private void btnFind_Click(object sender, System.EventArgs e) // Find and list Records
{
MessageBox.Show("Made it into btnFind_Click 0"); //TODO: Remove after debugging
try
{
if (barcodeScanner != null)
{
// Turn off the listening
barcodeScanner.BarcodeScan -= new BarcodeScanner.BarcodeScanEventHandler(barcodeScanner_BarcodeScan);
}
MessageBox.Show("Made it into btnFind_Click 1"); //TODO: Remove after debugging . . .
What could be preventing this code from being executed?
UPDATE
Based on Mike C's idea, I added a MessageBox to the button_close handler. And when I click it, it does fire, but only after other code runs first; in this case, that other code doesn't prevent the Close_Click from (eventually) firing; with the Find button, though, it completely preempts it...IOW, I see the message from the Close button at the end when I click it, but I never see any of the messages in the Find button handler when I click it...
UPDATE 2
Oh my lanta/say it ain't so, Joe! What's happening is an event is being kicked off in the form's overloaded constructor, and somehow this event is always fired just then (after clicking the find button). The message I'm seeing, that preempts everything in the button event handler, takes place in a method which is called by processBarcode() which is called by processBarcode1(), which is invoked from barcodeScanner_BarcodeScan1(), which is called by barcodeScanner_BarcodeScan(), which is set up in frmEntry's overloaded constructor. If the previous coder had intended to drive me insane, he couldn't have done much better.
I guess there's a reason there's so much maintenance work "out there" or "out here": because there's so much bad broken code AND because the cats who make such a mess scratch a bunch of sand on it and walk away.
And this code is chock full of "huh?!?##$%^?!?" moments, where bizarre gyrations are not commented on at all, and yet there is this comment:
// Check connection
checkConnection();
The problem could be that the Click event of the button is not subscribed to properly. If there is no line resembling
this.btnFind.Click += new System.EventHandler(this.btnFind_Click);
in the Designer file of the form, that's it.
I am developing a web application in asp.net and c#, now in a particular aspx page whenever I doubleClick(design view) on a button or on a drop down list, instead of going to
public void btn_click event or DropDown_SelectedIndexChanged event, the cursor points to protected void Page_Load only. Strange!! any remedy?
Not a fix for your VS misbehaving, if it is doing so. But this will help you wire up your events and perhaps notice anomalous event assignments:
Select the control in question, right-click>Properties, switch to the 'events' tab (lightning bolt) and either enter the name of a method or simply double click the empty space to generate an event handler in your codebehind.
This is also where you will see if Page_Load is already, for whatever reason, assigned to the event you are having trouble with.
HTH
May be both your btn_click event and DropDown_SelectedIndexChanged event delegates have Page_Load as the method. Check your events tab for button and dropdown.
this happens to me when I have my project running in debug mode and forget to stop it before editing my code. Long shot, but sometimes the obvious things are the things we overlook :)
.NET newbie alert
Using Visual C# 2008 Express Edition I have accidentally created a click event for a button. I then deleted the automatically-created method code, which resulted in an error saying that the function, which had now been referenced in the form loading code, could no longer be found.
Deleting the following line from the Form1.Designer.cs file's InitializeComponent() function...
this.btnCopy.Click += new System.EventHandler(this.btnCopy_Click);
... seems to do the trick, however, it makes me feel very dirty because of the following warning at the beginning of the #region:
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
I haven't been able to find a way to do this using the form designer, which I assume is the means implied by this warning. What is the correct way to do this?
You do have to be careful when working in the designer.cs files but you don't have to feel dirty about it (when I make the same mistake it is just easier to fix it the designer.cs file). You can do it visually like this:
Open the form in the form designer.
In the form designer, click the button of interest.
Press F4 (or right click the button and then click properties). The properties pane should show up.
At the top of the properties pane, click the lightning bolt. This shows the events for the button.
Find the click event and clear its handler.
Okay, I am usually the one advocating the use of notepad2 or some other text editor to perform coding tasks.
But, since you ask how to do so in the Designer...
Open the form where the erroneous event was added to a control.
Select the control.
Right-click, select "Properties".
Change to "Events" by selecting the button with the lighting-bolt icon.
Select the event you need to remove.
After placing the mouse in the box which is showing the event handler method name, delete all of the text in that box and press enter. This will remove the event handler and the delegate assignment for this event on your control.
The only caveat being: if you wish to preserve your event handler method (i.e. it is not auto-generated by Visual Studio) - you probably want to avoid deleting the assignment in this manner. Because when I say that it removes the event handler - I should say that the declaration of the event handler method in "Form1.cs" (for example) will be deleted as well.