Develop Reference

WinForm closing when 'ok' is selected on messagebox

I have a mainform where you can open another window and change options. One of the options is to copy highlighted text to the clipboard. if the user doesn't highlight text and clicks btnCopy then I want a message to be shown that no text was highlighted. When the user selects 'ok' I want the messagebox to close but I want the 'options' window to stay open.
Right now when the user clicks 'ok' both the message box and 'options' window closes. Why is the 'options' window closing?
Here is my code:
private void btnCopy_Click(object sender, EventArgs e)
{
string copySearch = txtSavedSearches.SelectedText;
if (copySearch == "")
{
DialogResult dialog = MessageBox.Show("You did not select anything to copy. Please select the query to copy.", "Copy search", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
else
{
Clipboard.SetText(copySearch);
this.Close();
}
}

You obviously set the DialogResult property of btnCopy to something different than DialogResult.None.
If - in a Form that is not the application's main window - a Button is clicked that has the DialogResult property set (to something different than None), this click causes the Form to close and the calling ShowDialog() method to return that DialogResult.
Find out where you set that property and remove it.
From MSDN (Button.DialogResult):
If the DialogResult for this property is set to anything other than None, and if the parent form was displayed through the ShowDialog method, clicking the button closes the parent form without your having to hook up any events. The form's DialogResult property is then set to the DialogResult of the button when the button is clicked

Why is the 'options' window closing?
The following line will cause the options form to close:
this.Close();
You don't need to do anything to close a MessageBox; it goes away by itself when the user clicks OK, and then your code resumes running from the point where MessageBox.Show was called. MessageBox.Show is a method that returns a value denoting which button the user clicked to get the box to go away (the value varies depending on a) which buttons you chose to show as part of the call to .Show(...) and b) which button the user clicked
Right now when the user clicks 'ok' both the message box and 'options' window closes. Why is the 'options' window closing?
This cannot be, as the message box is shown in the do-if-true part of the IF, and the call to close the options form is called in the ELSE (do if false) part. These two parts cannot run in succession, they must be one or the other. Either your option form closes without a messagebox showing, or a messagebox shows and your form doesn't close
-
Edit:
Renee believes you have set this property:
on your btnCopy button to be something other than None
And then you have also opened your options form like this:
OptionsForm f = new OptionsForm();
f.ShowDialog();
These two things combined will conspire to cause your form options to close any time that btnCopy is clicked (unless the clickevent is canceled)

Create a message box that user can choose to "Don't show it again."

Made a mass messenger & a multi-message/spammer in one, works fine, just want to make it even better. Obviously I had to write code to have skype allow the program so it can do what it does, here it is,
private void Form1_Load(object sender, EventArgs e)
{
//I entered a message box so it doesn't crash instantly.
MessageBox.Show("Please allow SkypeBot.vshost.exe to access skype. (Look at your Skype application)");
Skype skype = new Skype();
skype.Attach();
getContacts(skype);
}
how can I make it stop showing the MessageBox and just go straight to loading the form if the user already allowed it in the past (since it doesn't ask to allow it anymore after you've allowed it once)
here is what it looks like, if any are wondering, for some reason;
http://imgur.com/f0aaiZN,
works fine, just want to improve it so any answers to the requests above are appreciated :D

You can prevent showing the message by adding a check box to the dialog so the user can choose "Don't show this message again". Then you can save the value of the check box in settings and based on that setting, decide to show or not to show the dialog.
As a simple solution, you can create your own custom message box:
Create a new Form and name it MessageForm as your custom message box and put buttons like "OK" button and other buttons if you want. And for each button set proper value for DialogResult property. So when you show your form using ShowDialog if you click on a button, without writing code, the form will close with that dialog result.
Add a bool setting to your project Settings file, for example name it DontShow.
Put a check box on form and set its text to "Don't show this message again" and then handle CheckedChanged event and save the value of check box in the DontShow setting:
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
Properties.Settings.Default.DontShow = this.checkBox1.Checked;
Properties.Settings.Default.Save();
}
Now you can show your MessageForm this way:
if(!Properties.Settings.Default.DontShow)
new MessageForm().ShowDialog();
You can enhance your MessageForm by accepting the message in constructor or even adding a public static void ShowMessage(string) to it to use it like message box.

want to stop user input by messagebox but bypassed by a Enter keydown

I'm coding a windows form application running on a barcode scanner.
The plantform is .Net2.0CF/C#.
What i want is whenever user input wrong, the app will pop a messagebox and block the next input(actually,a scan action) until user click the OK on the screen.
But normally the user will continuously scan the next stuff as they didn't find anything went wrong, this will insert a Enter keydown so the messagebox will be closed, in one word, the messagebox does not stop the user.
How can i code this? Below is a very simple code snippet
private void tb_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode.ToString() == "Return")
{
if(!ValidateInput(tb.Text))
MessageBox.Show("Error");
}
}

You can create your own window (Form) that displays the error message, but does not react on the enter key.
It should contain a button which the user can click (as you wrote), however you need to make sure the button does not have focus when the window is displayed. (Because if it had focus, pressing the return key will "click" the button.)
A simple way for doing this is adding another control which has TabStop set to true (e.g. a textbox, another button) and which has a lower TabIndex property than the button.
Additionally, maybe you might want to do a
System.Media.SystemSounds.Beep.Play();
when showing the window to draw the user's attention to the window.

Form Opened As Modal Dialog Closes When Button Is Pressed, Even Though Close() is not called

I'm writing a Windows application that basically runs in the background with a notification icon to interact with it. The notification icon can do basic things like exit the application or show information about it. It can also launch a modal configuration dialog.
The code that creates the dialog is pretty straightforward:
using(var frmSettings = new SettingsForm(configuration))
{
frmSettings.ConfigurationChanged += ConfigurationChangedHandler;
frmSettings.UnhandledException += UnhandledExceptionHandler;
frmSettings.ShowDialog();
}
The SettingsForm class basically has three GroupBox controls, with a Label and TextBox control in each, and 4 Button controls at the bottom: "Advanced...", "Restore Defaults", "Cancel", and "Apply". Each TextBox has a Validating event handler wired up through the designer. Each button has a Click handler wired up through the designer. Each of them does pretty obvious things: opens another modal dialog with more advanced settings, restores the textboxes to their default values, closes the dialog, or saves the changes, fires the ConfigurationChanged event, and then closes the dialog (but only if all fields are valid!).
When there is a form entry error I cancel the corresponding Validating event by setting ((CancelEventArgs)e).Cancel = true. However, the default behavior of both forms was to prevent the user from changing focus when validation failed. I found this pretty annoying and eventually found the option in the designer to still automatically validate when the user leaves the field, but to allow them to leave even if validation fails: AutoValidate = EnableAllowFocusChange.[1]
My "Apply" button Click handler looks basically like this:
private void btnApply_Click(object sender, EventArgs e)
{
try
{
if(this.ValidateChildren())
{
this.Configuration.Field1 = this.txtField1.Text;
this.Configuration.Field2 = this.txtField2.Text;
this.Configuration.Field3 = this.txtField3.Text;
if(this.Configuration.Changed)
{
this.Configuration.Save();
this.OnConfigurationChanged(new ConfigurationChangedEventArgs(
this.Configuration));
}
this.Close();
}
}
catch(Exception ex)
{
this.OnUnhandledException(new UnhandledExceptionEventArgs(
"Failed To Apply Configuration Settings",
ex));
}
}
I'm currently testing out the code by breaking on the first line and stepping through the method line by line. Essentially, ValidateChildren is returning false as expected and the entire if block, including the this.Close() are skipped. Yet, if I step all the way to the bottom of the method and then step out of it I end up back on the frmSettingsForm.ShowDialog() line and the form is magically closed.
The "Apply" button is set as the form's AcceptButton. I wonder if it's implicitly attached a handler to the button's Click event to automatically close the form when the button is pressed. That doesn't sound like it logically should be assumed, especially considering there doesn't seem to be a way to cancel the Click event, but it's the only explanation that I can come up with. To test that theory, I have tried unsetting the AcceptButton in the designer, but my form still closes when the data is invalid.
What is closing my form and how do I stop it?
[1]: If anybody else has trouble finding it, it's a form property, not a property of each individual control (as I expected it would be).

Do you have the DialogResult of the Button set? If so, when you click the Button, the DialogResult of the Form will be set to that value and the modal Form will close. To prevent this, when validation fails in your Click handler, set the Form's DialogResult to DialogResult.None.

I don't know why that happens, but you could override the event OnFormClosing and check for the value of DialogResult according to your logic.
If (DialogResult != Windows.Forms.DialogResult.Cancel )
e.Cancel = True

MessageBox in c#

I want to show messagebox to the user, such that the user cannot refuse to confirm the message box. User should not be allowed to do anything else in the screen until he confirms the messagebox.
This is a windows based c# application.
The main thing is, even if i use windows message box. Some times it is hiding behind some screen. But for my case, i want message box to be on top most whenever it appears.
I am using some other third party applications, which over rides my message box. I want to overcome this.
How to do this...

You will have to create your own form, make it modal, change the z-order to make it always on top, and capture all keystrokes and mouse clicks.
Always on top: http://www.codeguru.com/cpp/w-d/dislog/article.php/c1857

Take a look at this article
MessageBox.Show Examples in Windows Forms C#
Edit:
You can also use the topmost property of a form to make it on top of all windows in a given application.
How to: Keep a Windows Form on Top
To display a form as a modal dialog call the ShowDialog method.
Form frmAbout = new Form();
frmAbout.ShowDialog();

If standard implementation of MessageBox doesn't do what you need, you will have to create your own form and use ShowDialog() method.

It sounds like the messagebox is being displayed on another thread. You need to make sure that you call MessageBox.Show on the main UI thread. Below is a code snippet that illustrates a way to achieve this:
public class FooForm: Form
{
//This is just a button click handler that calls ShowMessage from another thread.
private void ButtonShowMessage_Click(object sender,EventArgs e)
{
//Use this to see that you can't interact with FooForm before closing the messagebox.
ThreadPool.QueueUserWorkItem(delegate{ ShowMessage("Hello World!");});
//Use this (uncomment) to see that you can interact with FooForm even though there is a messagebox.
//ThreadPool.QueueUserWorkItem(delegate{ MessageBox.Show("Hello World!");});
}
private void ShowMessage(string message)
{
if( InvokeRequire)
{
BeginInvoke(new MethodInvoker( () => MessageBox.Show(message)));
}
else
{
MessageBox.Show(message);
}
}
}
I am assuming that you don't have a scenario where you have multiple UI threads and when one of them pops a messagebox, you want that messagebox to be modal for the entire UI. That's a more complicated scenario.