My app is WinForms .NET 4 (C#) and one of the forms keeps on closing automatically after pressing a button.
The form DOES have default Accept and Cancel buttons but these are not touched.
There is a ButtonTestConnection_Click event which when clicked, does its job but closes the form somehow.
I am using the mouse to click the button so this is NOT a case of cascading keystrokes.
I am NOT setting the DialogResult in this function.
I also tried to check for stray this.Close / this.Dispose calls but found none.
Here is the code:
private void ButtonTestConnection_Click (object sender, System.EventArgs e)
{
this.Enabled = false;
this.Cursor = System.Windows.Forms.Cursors.WaitCursor;
this.ProgressBar.Minimum = 0;
this.ProgressBar.Maximum = 500;
this.ProgressBar.Value = 0;
this.ProgressBar.Visible = true;
this.ButtonTestConnection.Visible = false;
try
{
while (this.ProgressBar.Value < this.ProgressBar.Maximum)
{
// Some proxy code.
this.ProgressBar.Value++;
}
}
catch
{
}
this.ProgressBar.Visible = false;
this.ButtonTestConnection.Visible = true;
this.ProgressBar.Invalidate();
System.Windows.Forms.Application.DoEvents();
System.Threading.Thread.Sleep(10);
this.Cursor = System.Windows.Forms.Cursors.Default;
this.Enabled = true;
System.Windows.Forms.MessageBox.Show(result.ToString());
}
Check if the property DialogResult on the button equals to None.
If not, then the form will be closed when you hit that button and the form will return the setting of the Button's DialogResult property.
Usually, this happens a lot when you copy/paste an existing form's button but forget to remove on the pasted button the original DialogResult setting
I have two forms. I have a button in mainForm. When i clicked button1 the main form will show and the button1 will be Enabled false. Now i want to Enable it to True when my ChildForm gets Close. PLease help me .
My code For Enable= False is
CstmersFrm cstFm = new CstmersFrm();
cstFm.MdiParent = this;
cstFm.Show();
cstFm.BringToFront();
btnCstmr.Enabled = false;
Iam trying to Enable= True is In cstmersFrm _Closed Event
mFrm = (mainForm)this.MdiParent;
mFrm.btnCstmr.Enabled = true;
You need to register to the child form Closed event on the main form:
Form child = new Form();
child.MdiParent=this;
child.Show();
child.FormClosed+=child_FormClosed;
and then set the button to Enabled:
void child_FormClosed(object sender, FormClosedEventArgs e)
{
btnCstmr.Enabled = true;
}
I Googled around but seems my problem happens when two gropboxes are overlapping, in my case they are not overlapping!
Problem is that the Visible property of groupbox doesn't work. what am I trying to do is that groupbox1 is visible when program starts and groupbox2 is not, by clicking on a button it should goes invisible and groupbox2 should appear, clicking the same button this action should be done vice versa.
here is my code:
private void button2_Click(object sender, EventArgs e)
{
if (groupBox2.Visible == false)
{
groupBox1.Visible = false;
groupBox2.Visible = true;
}
if (groupBox1.Visible == false)
{
groupBox1.Visible = true;
groupBox2.Visible = false;
}
}
Your problem is that after the first if-statement, it immediately checks if groupBox1.Visible is false, which it always will be. It then proceeds to flip it back.
Change the if to an else, or at least and else if and your code will work.
I would like to achieve the same effect like in this article but for windows forms, is it even possible without hosting the control on different Form?
EDIT
I'm more interested in implementing the exact behavior of the control in the article, showing the control on the form and blocking the calling function, but without using other form for this purpose.
You can create a UserControl with the two buttons and the label for the message, then set its visibility to false in the constructor:
public MyDialog()
{
InitializeComponent();
Visible = false;
}
Then you add three variables to the control:
Form _parent;
bool _result;
bool _clicked = false;
the parent Form will be the Form your control is contained in and must be set before using the control, since it has to know what has to be disabled.
public void SetParent(Form f)
{
_parent = f;
}
_result will contain the result of the dialog, and _clicked will be used to determine when to close your dialog. What has to be done when you show your dialog is:
set the label
disable the form (but not the dialog)
make the dialog visible
wait for the user to click one of the buttons
hide the dialog
reenable the parent form
return the result
So you could add this method to enable/disable the parent form:
private void ParentEnabled(bool aBool)
{
if (_parent == null)
return;
foreach (Control c in _parent.Controls)
if (c != this)
c.Enabled = aBool;
}
and use it in the ShowDialog method:
public bool ShowDialog(string msg)
{
if (_parent == null)
return false;
// set the label
msgLbl.Text = msg;
// disable the form
ParentEnabled(false);
// make the dialog visible
Visible = true;
// wait for the user to click a button
_clicked = false;
while (!_clicked)
{
Thread.Sleep(20);
Application.DoEvents();
}
// reenable the form
ParentEnabled(true);
// hide the dialog
Visible = false;
// return the result
return _result;
}
Obviously the buttons have the responsibility to set the _result and _clicked variables:
private void okBtn_Click(object sender, EventArgs e)
{
_result = true;
_clicked = true;
}
private void cancelBtn_Click(object sender, EventArgs e)
{
_result = false;
_clicked = true;
}
How about creating transparent form that in the middle contains text on opaque shape (whatever you like). Then at runtime you would resize this form to have same size as the window over which you want to display it and place it so that it covers it.
Is there a way to disable a tab in a TabControl?
Cast your TabPage to a Control, then set the Enabled property to false.
((Control)this.tabPage).Enabled = false;
Therefore, the tabpage's header will still be enabled but its contents will be disabled.
The TabPage class hides the Enabled property. That was intentional as there is an awkward UI design problem with it. The basic issue is that disabling the page does not also disable the tab. And if try to work around that by disabling the tab with the Selecting event then it does not work when the TabControl has only one page.
If these usability problems do not concern you then keep in mind that the property still works, it is merely hidden from IntelliSense. If the FUD is uncomfortable then you can simply do this:
public static void EnableTab(TabPage page, bool enable) {
foreach (Control ctl in page.Controls) ctl.Enabled = enable;
}
You can simply use:
tabPage.Enabled = false;
This property is not shown, but it works without any problems.
You can program the Selecting event on TabControler to make it impossible to change to a non-editable tab:
private void tabControler_Selecting(object sender, TabControlCancelEventArgs e)
{
if (e.TabPageIndex < 0) return;
e.Cancel = !e.TabPage.Enabled;
}
You could register the "Selecting" event and cancel the navigation to the tab page:
private void tabControl1_Selecting(object sender, TabControlCancelEventArgs e)
{
if (e.TabPage == tabPage2)
e.Cancel = true;
}
Another idea is to put all the controls on the tabpage in a Panel control and disable the panel! Smiley
You could also remove the tabpage from the tabControl1.TabPages collection. That would hide the tabpage.
Credits go to littleguru # Channel 9.
Presumably, you want to see the tab in the tab control, but you want it to be "disabled" (i.e., greyed, and unselectable). There is no built-in support for this, but you can override the drawing mechanism to give the desired effect.
An example of how to do this is provided here.
The magic is in this snippet from the presented source, and in the DisableTab_DrawItem method:
this.tabControl1.DrawMode = TabDrawMode.OwnerDrawFixed;
this.tabControl1.DrawItem += new DrawItemEventHandler( DisableTab_DrawItem );
Extending upon Cédric Guillemette answer, after you disable the Control:
((Control)this.tabPage).Enabled = false;
...you may then handle the TabControl's Selecting event as:
private void tabControl_Selecting(object sender, TabControlCancelEventArgs e)
{
e.Cancel = !((Control)e.TabPage).Enabled;
}
This will remove the tab page, but you'll need to re-add it when you need it:
tabControl1.Controls.Remove(tabPage2);
If you are going to need it later, you might want to store it in a temporary tabpage before the remove and then re-add it when needed.
The only way is to catch the Selecting event and prevent a tab from being activated.
The most tricky way is to make its parent equals null (make the tab alone without parent):
tabPage.Parent = null;
And when you want to return it back (will return it back at the end of pages collection) :
tabPage.Parent = tabControl;
And if you want to return it back in a specific location among the pages you can use :
tabControl.TabPages.Insert(indexLocationYouWant, tabPage);
I had to handle this a while back. I removed the Tab from the TabPages collection (I think that's it) and added it back in when the conditions changed. But that was only in Winforms where I could keep the tab around until I needed it again.
I've removed tab pages in the past to prevent the user from clicking them. This probably isn't the best solution though because they may need to see that the tab page exists.
Using events, and the properties of the tab control you can enable/disable what you want when you want. I used one bool that is available to all methods in the mdi child form class where the tabControl is being used.
Remember the selecting event fires every time any tab is clicked. For large numbers of tabs a "CASE" might be easier to use than a bunch of ifs.
public partial class Form2 : Form
{
bool formComplete = false;
public Form2()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
formComplete = true;
tabControl1.SelectTab(1);
}
private void tabControl1_Selecting(object sender, TabControlCancelEventArgs e)
{
if (tabControl1.SelectedTab == tabControl1.TabPages[1])
{
tabControl1.Enabled = false;
if (formComplete)
{
MessageBox.Show("You will be taken to next tab");
tabControl1.SelectTab(1);
}
else
{
MessageBox.Show("Try completing form first");
tabControl1.SelectTab(0);
}
tabControl1.Enabled = true;
}
}
}
I've solved this problem like this:
I've got 3 tabs and I want to keep user at the first tab if he didnt log in,
so on the SelectingEvent of TabControl I wrote
if (condition) { TabControl.Deselect("2ndPage"); TabControl.Deselect("3dPage"); }
The user cannot click on tabs to navigate, but they can use the two buttons (Next and Back). The user cannot continue to the next if the //conditions are no met.
private int currentTab = 0;
private void frmOneTimeEntry_Load(object sender, EventArgs e)
{
tabMenu.Selecting += new TabControlCancelEventHandler(tabMenu_Selecting);
}
private void tabMenu_Selecting(object sender, TabControlCancelEventArgs e)
{
tabMenu.SelectTab(currentTab);
}
private void btnNextStep_Click(object sender, EventArgs e)
{
switch(tabMenu.SelectedIndex)
{
case 0:
//if conditions met GoTo
case 2:
//if conditions met GoTo
case n:
//if conditions met GoTo
{
CanLeaveTab:
currentTab++;
tabMenu.SelectTab(tabMenu.SelectedIndex + 1);
if (tabMenu.SelectedIndex == 3)
btnNextStep.Enabled = false;
if (btnBackStep.Enabled == false)
btnBackStep.Enabled = true;
CannotLeaveTab:
;
}
private void btnBackStep_Click(object sender, EventArgs e)
{
currentTab--;
tabMenu.SelectTab(tabMenu.SelectedIndex - 1);
if (tabMenu.SelectedIndex == 0)
btnBackStep.Enabled = false;
if (btnNextStep.Enabled == false)
btnNextStep.Enabled = true;
}
tabControl.TabPages.Remove(tabPage1);
This is an old question, but someone may benefit from my addition. I needed a TabControl that would show hidden tabs successively (after an action was performed on the current tab). So, I made a quick class to inherit from and called HideSuccessive() on Load:
public class RevealingTabControl : TabControl
{
private Action _showNextRequested = delegate { };
public void HideSuccessive()
{
var tabPages = this.TabPages.Cast<TabPage>().Skip(1);
var queue = new ConcurrentQueue<TabPage>(tabPages);
tabPages.ToList().ForEach(t => t.Parent = null);
_showNextRequested = () =>
{
if (queue.TryDequeue(out TabPage tabPage))
tabPage.Parent = this;
};
}
public void ShowNext() => _showNextRequested();
}
There is the XtraTabPage.PageEnabled property allowing you to disable certain pages.
Here the solution that i implement:
private void switchTapPage(TabPage tabPage)
{
foreach(TabPage page in tabControl1.TabPages)
{
tabControl1.TabPages.Remove(page);
}
tabControl1.TabPages.Add(tabPage);
}
Basically, i just call this method sending the tabPage that i currently need to show, the method will remove all the tabPages on the tabControl and after that it will just add the one that i sent it.
So the rest of the tabHeaders will not shown and they will be inaccessible, because they dont even exists in the tabControl.
I took the idea from the #stormenet answer.
You can do it through the tabpages: tabPage1.Hide(), tabPage2.Show() etc.
In the form load event if we write this.tabpage.PageEnabled = false, the tabpage will be disabled.
Assume that you have these controls:
TabControl with name tcExemple.
TabPages with names tpEx1 and tpEx2.
Try it:
Set DrawMode of your TabPage to OwnerDrawFixed;
After InitializeComponent(), make sure that tpEx2 is not enable by adding this code:
((Control)tcExemple.TabPages["tpEx2").Enabled = false;
Add to Selection tcExemple event the code below:
private void tcExemple_Selecting(object sender, TabControlCancelEventArgs e)
{
if (!((Control)e.TabPage).Enabled)
{
e.Cancel = true;
}
}
Attach to DrawItem event of tcExemple this code:
private void tcExemple_DrawItem(object sender, DrawItemEventArgs e)
{
TabPage page = tcExemple.TabPages[e.Index];
if (!((Control)page).Enabled)
{
using (SolidBrush brush = new SolidBrush(SystemColors.GrayText))
{
e.Graphics.DrawString(page.Text, page.Font, brush, e.Bounds);
}
}
else
{
using (SolidBrush brush = new SolidBrush(page.ForeColor))
{
e.Graphics.DrawString(page.Text, page.Font, brush, e.Bounds);
}
}
}
It will make the second tab non-clickable.
I could not find an appropriate answer to the question. There looks to be no solution to disable the specific tab. What I did is to pass the specific tab to a variable and in SelectedIndexChanged event put it back to SelectedIndex:
//variable for your specific tab
int _TAB = 0;
//here you specify your tab that you want to expose
_TAB = 1;
tabHolder.SelectedIndex = _TAB;
private void tabHolder_SelectedIndexChanged(object sender, EventArgs e)
{
if (_TAB != 0) tabHolder.SelectedIndex = _TAB;
}
So, you don't actually disable the tab, but when another tab is clicked it always returns you to the selected tab.
in C# 7.0, there is a new feature called Pattern Matching. You can disable all tabs via Type Pattern.
foreach (Control control in Controls)
{
// the is expression tests the variable and
// assigned it to a new appropriate variable type
if (control is TabControl tabs)
{
tabs.Enabled = false;
}
}
Use:
tabControl1.TabPages[1].Enabled = false;
By writing this code, the tab page won't be completely disabled (not being able to select), but its internal content will be disabled which I think satisfy your needs.
The solution is very simple.
Remove/comment this line
this.tabControl.Controls.Add(this.YourTabName);
in IntializeComponent() method in MainForm.cs
MyTabControl.SelectedTab.Enabled = false;