I am working on a personal project in winforms just to gain some experience in it since I've never had the chance to work with it before. So, I'm quite the n00b when it comes to Winforms. This is the error I'm encountering:
In form BudgetTracker, I have a button called 'AddCat'. Below is the form's constructor and the button's click eventHandler:
public form_BudgetTracker()
{
InitializeComponent();
setEvents();
}
public void setEvents()
{
this.btn_AddCat.Click += new System.EventHandler(this.btn_AddCat_Click);
}
private void btn_AddCat_Click(object sender, EventArgs e)
{
form_NewCat NewCatForm = new form_NewCat();
var NewCatFormResult = NewCatForm.ShowDialog();
NewCatForm.Show();
}
In the NewCat form that comes up, I have a Cancel button. Code:
public form_NewCat()
{
InitializeComponent();
SetEvents();
}
private void SetEvents()
{
this.btn_Add.Click += new System.EventHandler(this.btn_Add_Click);
this.btn_Cancel.Click += new System.EventHandler(this.btn_Cancel_Click);
}
private void btn_Cancel_Click(object sender, EventArgs e)
{
this.Close();
}
The problem I'm facing is, when I click Add, the new form comes up. At this point, if I click Cancel, the form disappears but instantly a new instance of the form appears. I then click cancel again, and the form disappears.
What part of my code is making the form appear twice. I checked the contructors etc, but couldn't figure it out. Any help or pointers would be appreciated.
PS - As I mentioned, I'm new to winforms programming, so any cues or pointers would be appreciated as well.
private void btn_AddCat_Click(object sender, EventArgs e)
{
form_NewCat NewCatForm = new form_NewCat();
var NewCatFormResult = NewCatForm.ShowDialog(); // <-- opens the first time
NewCatForm.Show(); // <-- opens the second time
}
Judging from your code, you're simply showing the form twice!!!
form_NewCat NewCatForm = new form_NewCat();
var NewCatFormResult = NewCatForm.ShowDialog();
NewCatForm.Show();
The second line shows the form and blocks the method until DialogResult is set, then the third line shows the form without blocking the method.
Simply remove the third line!
Try stepping through the code using the F8 key instead of running it, or hitting F5. It will show you line by line what it's about to execute.
delete NewCatForm.Show();
Related
So, I'm making a payroll management system as a hobby project to help my resume and general knowledge of c#. So, I'm making a UI and I can open a new window just fine with this code:
private void button1_Click(object sender, EventArgs e)
{
CreateAdminAcct createAcct = new CreateAdminAcct();
createAcct.StartPosition = FormStartPosition.CenterScreen;
createAcct.Show();
this.Hide();
}
however, I don't know the event to check when the little red "x" button is clicked, because when that button is clicked, I want to go back to the main screen because I hide the main screen when that button is clicked, and when i click the red "x" on the screen that just opened, it closes, but the application continues to run in the background.
If there is some better way to manage multiple menus, I'm open to suggestions, however, this is what I've found easiest.
Thanks in advance
I second Robert Harvey's suggestion; this gives the user the reassurance tha tht emain window is still open/ nothing got lost, but it's unreachably "behind" the CreateAdminAcct form while the CreateAdminAcct form is open
private void button1_Click(object sender, EventArgs e)
{
CreateAdminAcct createAcct = new CreateAdminAcct();
createAcct.StartPosition = FormStartPosition.CenterScreen;
createAcct.ShowDialog();
//do any code here that needs to access createAcct before it's lost
MessageBox.Show(createAcct.NewAdmin.Name);
}
If you really do want to hide your main form, pass the main form itself to createAcct, and make it createAcct's job to re-open the main form when it is closing
private void button1_Click(object sender, EventArgs e)
{
CreateAdminAcct createAcct = new CreateAdminAcct(this); //note passing this form to constructor
createAcct.StartPosition = FormStartPosition.CenterScreen;
createAcct.Show();
}
class CreateAcctForm : Form{
private Form _showWhenClosing;
CreateAcctForm(Form revertTo){
InitializeComponent();
_showWhenClosing = revertTo;
}
}
void Form_Closing(object sender, ...){ //event
_showWhenClosing.Show();
}
Side note: please rename your controls after you drop them ona form. code that's stuffed with label57, textbox25 is effectively obfuscated and really wearisome to follow
I checked and found this article that is referred to MANY times in this type of question, and it is NOT the answer I want...
I have a form, Form_Main frmMainPage, it creates Form_Status frmStatus.
When it does so, I disable the controls on frmMainPage so the user can't mess with things while things are processing.
When things are done processing they can close the frmStatus window to go back to frmMainPage to continue working. I cannot re-enable the controls from frmStatus. I tried to use the frmMainPage_Enter, but it goes crazy when it first loads, so that isn't really an option.
I have the following in Form_Main.cs
public void EnableForm() {
this.gridData.Enabled = true;
this.txtLocation.Enabled = true;
this.txtSupplier.Enabled = true;
this.txtItem.Enabled = true;
this.FillTable("", "", "");
}
When I use this (per article above):
private void btnClose_Click(object sender, EventArgs e) {
Form_Main f2 = new Form_Main();
f2.Show();
f2.EnableForm();
this.Close();
}
It creates a second Form_Main, which is not what I want. I want to know how to change the controls in the existing form.
Edit: No, it is not this that was also suggested. Most of the answers deal with changing controls on Form 2 from Form 1 when Form 2 is created by Form 1. In my case I need to do the opposite and change controls on Form 1 FROM Form 2, which was created by Form 1. Kind of a circular thing.
I can think of a couple of ways to do this. First (and most common) is to show the second form modally (which means that the first form's code pauses while the second form's code is running):
private void button1_Click(object sender, EventArgs e)
{
var statusForm = new frmStatus();
// ShowDialog will prevent frmMainPage from being accessible.
// This form's code will pause at the next line until the second form is closed
statusForm.ShowDialog();
}
There are occasions where you want to have both forms accessible at the same time. If this is the case, another method would be to add an event handler for the second form's FormClosed event, where you can re-enable the controls on the first form. This will allow both forms to be accessed at the same time:
private void button1_Click(object sender, EventArgs e)
{
var statusForm = new frmStatus();
// Add an event handler for the second form's FormClosed event, and
// put code in that event handler to re-enable controls on this form
statusForm.FormClosed += statusForm_FormClosed;
// Disable our controls on this form and show the second form
DisableForm();
statusForm.Show();
}
private void statusForm_FormClosed(object sender, FormClosedEventArgs e)
{
// When the second form closes, re-enable controls on this form
EnableForm();
}
private void DisableForm()
{
this.gridData.Enabled = false;
this.txtLocation.Enabled = false;
this.txtSupplier.Enabled = false;
this.txtItem.Enabled = false;
}
public void EnableForm()
{
this.gridData.Enabled = true;
this.txtLocation.Enabled = true;
this.txtSupplier.Enabled = true;
this.txtItem.Enabled = true;
this.FillTable("", "", "");
}
you dont need to do this disable enable.
you just need to show your new from with ShowDialog(); like this:
frmStatus.ShowDialog();
instead of just:
frmStatus.Show();
Hi I'm relatively new to C# and completely new to windows form and basically trying to create a subliminal messaging program that at timed intervals will quickly display a message for it to then be hidden again.
I've managed to by looking through various other posts created another form that will pop up and then hide very quickly using
msgObject.Activate();
that brings the form to the front. However it is stopping me from being able to type when I'm working and I basically wanting to know if it is possible to make some kind of message or form appear at the front of all my other programs without it interrupting my current work or opening or closing of other windows and tasks if that makes sense. As currently it brings the form to the front of everything but will also stop me from being able to type etc.
I'm not sure if this is possible with my current method of using a form but if there is a way of achieving the result I'm after I'd be very grateful to find out
Thanks.
Here is more of my code to clarify
public partial class FormHomePage : Form
{
private bool startSubliminal = false;
msg msgObject = new msg();
List<string> subliminalMessages = new List<string>();
public FormHomePage()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void timer1_Tick(object sender, EventArgs e)
{
if (startSubliminal)
{
msgObject.Show();
msgObject.BringToFront();
msgObject.Activate();
}
}
private void button1_Click(object sender, EventArgs e)
{
subliminalMessages.Add(txtBox1.Text);
msgObject.LabelText = txtBox1.Text;
txtBox1.Text = string.Empty;
startSubliminal = true;
msgObject.Show();
msgObject.BringToFront();
}
private void timer2_Tick(object sender, EventArgs e)
{
msgObject.Hide();
}
}
How are you showing the second form (the message form) in the first place? You're probably using .Show() (right?), which will make the form "steal" the focus anyway. The same applies to .Activate() and .BringToFront().
Instead, what you can do is to show the message form and make sure it stays on top the current form, and then activate the current/main form once again.
Something like this should work:
var frm = new YourMsgForm();
frm.Show(this);
this.Activate();
Here's a demonstration:
Note that I used .Show(this) instead of .Show(), that's in order to set the current form as the Owner of the new one, that way we guarantee that the new form will stay on top of the current one. This is equivalent to calling frm.Owner = this; then frm.Show();.
Another way to make sure the form stays on top is by setting the TopMost property instead of the Owner property. However, doing so will make the new form on top of the other windows as well (not just your application).
I'm currently trying to bring two forms to the front when I activate them from the Task bar or via Alt+Tab. The problem is that I can't close the main form if the second one exists:
This is the code I use
private void Haupt_Activated(object sender, EventArgs e)
{
cardLibrary.Focus(); //Focus the second form
this.Focus(); //refocus the first one
}
What am I doing from?
EDIT:
Haupt is the main form.
CardLib is variable in Haupt
this is how CardLib is called:
private void cMenuOpenLibrary_Click(object sender, EventArgs e)
{
if (!Config.libOpen)
{
if (cardLibrary == null) cardLibrary = new CardLib(this);
cardLibrary.Show();
cardLibrary.Left = this.Left - cardLibrary.Width - 5;
cardLibrary.Top = this.Top;
}
}
EDIT 2: Sry I was being dumb. Adding closing the CardLib via Haupt_FormClosed fixed it.
If you are calling second form from
Second.ShowDialog();
then this will create this problem as a dialog retains focus until it is closed
Instead of
Second.ShowDialog();
use
Second.Show();
How can this.focus in second form focus the first form???
this.Focus(); //refocus the first one
I have a countdown Timer form - on the first form the user will enter the countdown time - warning times, end message, etc. There are also two Radio buttons (Max/Min) and depending on which is selected they will open a new Max or Min form where the time will actually start to countdown. It is working fine and counting down as I expect. However, if I exit the Max or Min form and try to run again with new times I get the error. The code is below - note the comment out ShowDialog(this); was something I tried - it let me close and open the new forms ok but it did not actually start the countdown. UpdateLabels is the function that does the updating of Labels.
bool Max = rbMax.Checked;
if (Max == true)
{
//_Max.ShowDialog(this);
_Max.Show();
}
else
//_Min.ShowDialog(this);
_Min.Show();
UpdateLabels();
}
I also tried the following which I read online as a possible solution but it also did not work...
private void Max_FormClosing(object sender, FormClosingEventArgs e)
{
this.Hide();
this.Parent = null;
}
Can anyone help me out - I can post the UpdateLabels function if needed. I am pretty new to UI C# development so any help would be great. Thanks.
The problem is, that a closed form can not be used anymore (be reopened). Thats why the code you posted tries to stop closing and only hides your window. But for doing this, the Cancel-property must be set to true:
private void Max_FormClosing(object sender, FormClosingEventArgs e) {
this.Hide();
this.Parent = null;
e.Cancel=true;
}
To show the form after closing it this way, show it with the Show() method.
However this is probably only a workaround and you could solve the problem with another design.
Maybe it would be wise, to create a new instance of your form, every time you need it, instead of trying to reopen it every time. This also has the advantage that the form only requesires resources if it is really needed.
What you can do is add a following check before calling .Show method:
if(_Max == null || _Max.IsDisposed)
_Max = new MaxForm();
_Max.Show();
and similarly for _Min form
Whenever a form is closed, all its resources are freed. This means that you can't access the object any more, since it no longer exists - it's been freed and deleted from memory. To prevent that, you can cancel the closing of the form, and hide it instead (which will appear transparent to the user).
this.Hide();
e.Cancel=true;
An updated version of your code is as follows:
private void Max_FormClosing(object sender, FormClosingEventArgs e)
{
e.Cancel = true;
this.Hide();
this.Parent = null;
}
The solution is simple that instantiate the object of the called form in the button click event e.g.
private void buttonSetting_Click( object sender, EventArgs e )
{
***_setting = new SettingWindow();*** //When I need to show the settings window
_setting.Show();
}
create new instatnce if object is not available
if(frmRGB==nullptr || frmRGB.IsDisposed==true )
{
frmRGB= new Form();
}
Create Object inside button click event
like this
private void btn_supplier_order_Click(object sender, EventArgs e)
{
form_supplier_order so = new form_supplier_order();
so.Show();
}