How to change a control property from a UserControl - winforms

I have a form named Form1 and 2 UserControl named USC1,USC2. In USC1 i have a Button. Two USCs(USC1,USC2) have been added to Form 1 and the Visible attribute of USC2 is set to false. When i click the button in USC1, how do I get the USC2 to Visible (USC2.Visible = true) ?
Picture:

Change the modifier of the Button to public or expose it via a property. In the form's constructor after InitializeComponent(), subscribe to the button's click event:
public Form1()
{
InitializeComponent();
USC1.button1.Click += OnButtonClick;
}
private void OnButtonClick(object sender, EventArgs e)
{
USC2.Visible = true;
}

Related

OnAddedToForm designer event for UserControl?

Is there an event for a UserControl that only fires the first time it is added to a form? I basically want to show a memmo on how to use the control to the user once they add the control into the form, but never show it afterwards (until they add another instance of this control).
An easy way to do that could be:
Use the event ParentChanged from Control : Control.ParentChanged Event
UserControl is an heritance of Control
In your UserControl, you could use a private field to define if the item has been already added to a parent.
This code could work for you:
public class CustomUserControl : UserControl
{
private bool _firstTimeAdded = false;
private void Init()
{
this.ParentChanged += CustomUserControl_ParentChanged;
}
private void CustomUserControl_ParentChanged(object sender, EventArgs e)
{
if (Parent is Form && !_firstTimeAdded)
{
_firstTimeAdded = true;
// Show your memmo
}
}
}

Adding tabpage to a tabcontrol which is on another form on click of button

I have a winform called form1 which has tabcontrol with some tabpages and one button on clicking of which I open another form called form2. I want to add tabpage to form1 tabcontrol on click of button which is present on form2.
Assumed that you have not created a tabcontrol at runtime in the Firstform.
In FirstForm.cs
private void button1_Click(object sender, EventArgs e)
{
SecondForm obj = new SecondForm(this);
obj.Show();
}
public void addTabpage()
{
TabPage tbpg = new TabPage();
tbpg.Text = "New tabpage";
tabControl1.TabPages.Add(tbpg);
this.BringToFront();
}
In SecondForm.cs, change the constructor as follows
static FirstForm objpub;
public SecondForm(FirstForm obj)
{
InitializeComponent();
objpub = obj;
}
private void button1_Click(object sender, EventArgs e)
{
if (objpub != null)
{
objpub.addTabpage();
}
}
If this answer does not meet your problem, then provide your code.
Cheers !

Windows Forms method Form.ShowDialog() strange behaviour

I was trying to show a form(FormChild), with some radio buttons in, just to select, close, and get the value of the selected radio button from the calling form(FormParent). On a click event handler for a Button in FormParent, I just did:
var formChild=newFormChild();
formChild.ShowDialog(this);
All was working great until I decided to handle the CheckedChanged event of one of the RadioButtons inside FormChild:
private void SomeRadioButton_CheckedChanged(object sender, EventArgs e)
{
Close();
}
Now the formChild.ShowDialog(this); did not showed formChild and formChild immediately returns DialogResult.Cancel.
Any explanation on this?
Thanks in advance
The lowest Tab Index radiobutton will be checked by default, If this event handler is assigned to that button it will cause the situation that you are describing.
You can either change your Tab Order or create a Boolean Flag that is set in your Forms Shown EventHandler to keep it from Triggering until you check it again.
public partial class Form1 : Form
{
bool initDone;
public Form1()
{
InitializeComponent();
}
private void radioButton1_CheckedChanged(object sender, EventArgs e)
{
if (initDone)
{
if (((RadioButton)sender).Checked == true)
{
Close();
}
}
}
private void Form1_Shown(object sender, EventArgs e)
{
initDone = true;
}
}
Is there anywhere if your code that sets the value of the RadioButton? If you programmatically set the "Checked" property of the RadioButton, it will fire the event.
In your situation, the event handler contains your Form.Close() so the form never gets the chance to be visible to the user.
Note: Setting the RadioButton.Checked as "true" in the designer will not fire the event.

how to change the layout of a control inside a parent wpf form from a child winform?

i have two separate projects inside a solution, one is a wpf the other is windows form and i have referenced the winform to the wpf project.. Inside the wpf window is an image control, when clicked, a windows form with a button would appear.
How i can be able to change the image source of the image control inside the wpf form when the button inside the winform is clicked...
i have seen a similar question to this but i cant understand the answers...
You could pass a delegate/Action into the Winform to perform the action
Here is a very quick example
WPF
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
// pass in the method you want to call when the winform button is clicked
var winform = new Form1(() => ChangeImage()).ShowDialog();
}
private void ChangeImage()
{
// your change image logic
}
}
Winforms
public partial class Form1 : Form
{
private Action _action;
public Form1()
{
InitializeComponent();
}
public Form1(Action action)
{
_action = action;
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
if (_action != null)
{
// call the method in the WPF form
_action.Invoke();
}
}
}

Toggle DataGridView row selection where SelectionMode is FullRowSelect

I have a DataGridView where SelectionMode=FullRowSelect and MultiSelect=False.
When a user clicks on a row it is selected as expected. However, clicking on the same row again does not deselect the row.
How can the row selection be made to toggle between selected and unselected?
As far as I know there is no out of the box functionality that will do this.
I managed to get the effect you are asking for with the following code:
public partial class Form1 : Form
{
private bool selectionChanged;
public Form1()
{
InitializeComponent();
}
private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
if (!selectionChanged)
{
dataGridView1.ClearSelection();
selectionChanged = true;
}
else
{
selectionChanged = false;
}
}
private void dataGridView1_SelectionChanged(object sender, EventArgs e)
{
selectionChanged = true;
}
}
That uses the dataGridView's SelectionChanged and CellClick events, along with a class level variable holding the state of the selection.

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