I am new to C# programming language. I am trying to create a windows form application in c# .net using VS 2012. I have created a text label and I want to display a text when the application is loaded. I see only click event rather than load event. would anyone please suggest what to do? (I am expecting something like "lblText_Load")
The label does not have an event for loaded. You can either use the Form's Load event, or the OnShown event.
I suggest using the OnShown event because this will be triggered after the form is loaded and displayed. The OnLoad event for the form occurs when it begins to load not after.
You can use the form's Load event. See MSDN for additional information.
private void Form1_Load(object sender, System.EventArgs e)
{
lblText.Text = "w00t \o/";
}
On the load event of the form you can do what you want.
private void Form1_Load(object sender, System.EventArgs e) {
lblText.Text = "Evaluation Tool";
}
Forms have lots of events you can use (Load, Activated, Shown , etc.)
Related
I am a VB.NET Developer trying to learn C# in my spare time. Please see the code below:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.Load += Form1_Load;//event handler code
}
private void Form1_Load(object sender, EventArgs e)
{
string test = "got here";
}
}
This is a Windows Form app. If I add the event handler code to the constructor then Form1_Load handles the load event.
Now see the Web Forms app below:
public partial class _Default : Page
{
protected void Page_Load(object sender, EventArgs e)
{
string s = "got here";
}
}
Page_Load is fired without any event handler code?
My question is: Are Page Life Cycle events automatically wired to function names e.g. Page_Load automatically handles the page load in c# ASP.NET? Why does this not apply to Windows Forms? Where do you put the Event Handler code in windows forms? the .designer?
In Asp.Net you can set AutoEventWireup value. Please check this article https://support.microsoft.com/en-us/kb/324151
However when I need to handle an event the easiest way for me is going to the aspx source view, find the the runatserver control and specify my handler there. For example:
<asp:TextBox ID="txtCustomer" runat="server" />
As you type "on..." the list of events is shown (events are identified by ray icon), select OnLoad and Create.
<asp:TextBox ID="txtCustomer" OnLoad="txtCustomer_Load" runat="server" />
Now go to your cs code behind file and you'll see default handler was created there.
protected void txtCustomer_Load(object sender, EventArgs e)
{
}
Another option is going to Design View, right click on the control and go to properties. Click on the ray icon and add your handler.
Winform do not auto fire event as Asp.Net because winform has not page life Cycle.
To handle a event in winform, you select a component in design mode. Look at the right panel, you will see the events tab. There are alot event here. Double click to handle it.
I am following this walkthrough on MSDN: Creating a Custom Tab by Using the Ribbon Designer
Looking at steps 3 and 4:
In step 3 it adds an event handler to the ribbon_Load function, basically adding a click event to a button in the ribbon:
private void MyRibbon_Load(object sender, RibbonUIEventArgs e)
{
this.button1.Click += new RibbonControlEventHandler(this.button1_Click);
}
Then, in step 4 they add another event handler in the way that I am more used to, like so:
private void button1_Click(object sender, RibbonControlEventArgs e)
{
MergeReportInterface ui = new MergeReportInterface();
ui.ShowDialog();
}
I am not really understanding the purpose of this, because all it does is cause the event to fire twice. If I comment out the event handler that was added to the load function the event occurs once.
Could someone please explain to me what the point of this is? if there is any, or if there is some error on the MSDN site. What should be the proper way to handle a ribbon click event?
private void button1_Click(object sender, RibbonControlEventArgs e)
{
MergeReportInterface ui = new MergeReportInterface();
ui.ShowDialog();
}
This is not adding an event handler. This is the method that your event will call.
this.button1.Click += new RibbonControlEventHandler(this.button1_Click);
This is saying 'When button1 fires its Click event, call this.button1_Click'.
Your code only sets up one event handler, it should only fire once.
However, it's likely you created the button1_Click method by double clicking a button on your form designer. This, behind the scenes, adds an additional event handler. This is why you're getting the event fired twice.
So you have two options:
Go back into the IDE and remove the click handler via your form designer. Go to your code and manually write the method button1_Click.
OR
Remove this line: this.button1.Click += new RibbonControlEventHandler(this.button1_Click);, as VisualStudio is doing that for you automatically.
As the title suggests, I cannot get a single event to fire from an MDIChild application. No mouse event, no load, keypress, nothing at all.
private void btnSave_Click(object sender, EventArgs e)
{Console.WriteLine("Clicked");}
this.btnSave.Click += new System.EventHandler(this.btnSave_Click);
Selected the event from the properties window, manually subscribed to the event and yet nothing at all.
As the comments suggest you could insert a break point to see if these events are being fired.
From the information in your question it looks like the issue is that you're calling
Console.WriteLine
From a Winforms application.If you want to see somethng appear you could try
MessageBox.Show("Clicked")
Console applications would show Console.WriteLine, but the fact that you have buttons suggests a WinForms app.
Im designing a dialerPad form using Windows form, there is a textbox which should only take numbers and not text, my problem is that when i add the code
private void txtDialedNumber_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
//Blaah Blaah Code;
}
but its not getting registered in the other DialPad.Designer.CS page. For example the fallowing code registers TextChangedEvent
this.txtDailedNumber.TextChanged += new System.EventHandler(this.txtDailedNumber_TextChanged);
Can anybody help me on this?
You should never change *.designer.cs files manually.
What you should be doing is opening the design view of your form, selecting the object, and then setting the event handler in the objects properties:
Alternatively, if you want to register event handler manually (instead of using the designer), just put it under the InitializeComponent() call in the constructor for your form.
I would try to simplify Greg's answer.
Select the text box > go to properties > events tab> KeyPress Event > select the method this.txtDailedNumber.KeyPress
You are done.
I am working on a C# WinForm application.
I want to trigger some processing once the form has been "shown" and the layout of the form is complete.
I am using the "_Shown" event, but this seems to trigger before the layout of the form has completed. Is there event I can use that fires once the layout is complete?
Put Application.DoEvents() at the start of the form's Shown event handler. This will force all the controls to be rendered.
I don't see an event after Shown you can use for this purpose. Could you not use a timer to delay your processing in the Shown event?
An old trick in VB6 used to be to use the Paint event:
bool firstShown = false;
void form_Paint(Object sender, EventArgs e) {
if ( !firstShown ) {
YourMethodThatNeedsToRunOnShown();
firstShown = true;
}
//the rest of your paint method (if any)
}
It is a little hacky, but it does work
This works for me and is much less "hacky" than other suggestions:
protected override void OnLayout(LayoutEventArgs levent)
{
base.OnLayout(levent);
if(someControl == null)
return; // be careful of OnLayout being called multiple times
// otherwise, do some stuff here, set control sizes, etc.
}
AS far as I can remember the event order is something like
Form.Load
Form.Layout
Form.VisibleChanged
Form.GotFocus
Form.Activated
Form.Shown
So if something is still happening after Form.Show it's because of the way you coded it.
Are you maybe creating the form dynamically?
The best solution is the Shown() event: http://msdn.microsoft.com/en-us/library/system.windows.forms.form.shown.aspx
"The Shown event is only raised the first time a form is displayed; subsequently minimizing, maximizing, restoring, hiding, showing, or invalidating and repainting will not raise this event."
Try using Form.GotFocus (inherited from control)..
something like this.
private void Form1_Load(object sender, EventArgs e)
{
this.GotFocus += new EventHandler(Form1_gotFocus);
this.Focus();
}
private void Form1_gotFocus(object sender, EventArgs e)
{
// You will need to Switch focus from form at the end of this function,
//to make sure it doesnt keep Firing.
}
According To msdn , the following happens:
When you change the focus by using the keyboard (TAB, SHIFT+TAB, and so on), by calling the Select or SelectNextControl methods, or by setting the ContainerControl..::.ActiveControl property to the current form, focus events occur in the following order:
Enter
GotFocus
Leave
Validating
Validated
LostFocus