Properties and Events

  • Thread starter Thread starter Ryan Ternier
  • Start date Start date
R

Ryan Ternier

I'm running a small C# app and I am trying to accomplish the following:

//Presentation Tier
txtMyTextBox.text = MyObject.SomeProperty;



//Business Tier

class MyObject
{
.....
public string SomeProperty
{
....
}

public event System.EventHandler SomeProperty_OnChange;
.....
}

What I want is when anything modifies the SomeProperty property, for the
PresentationTier to be pushed that data.

The class the SomeProperty belongs to runs many loops, and I want the
property text changing each time it hits a new loop to show the new data in
the textbox without the Presentation Tier having to do any of the work.

I did this in VB a long time ago, and totally forget how to do it haha.

Any help would be very appreciated.
 
Ryan,

Instead of naming your event SomeProperty_OnChange, name it
SomePropertyChanged. This will cause data bindings to update when you fire
the event.

Hope this helps.
 
Whenever you set your property you'll get an event.

public class MyObject {
public event EventHandler SomeProperty_Changed;
public string SomeProperty {
get { return this.someProperty; }
set { if ( this.someProperty != value ) { this.someProperty = value;
OnSomePropertyChanged(null); }
}

private void OnSomePropertyChanged(EventArgs e) {
if ( SomeProperty_Changed != null ) { SomePropertyChanged(this, e); }
}
}
 
Ok,

I'm running:
public string ConnectedTo
{
get
{
return p_strServer;
}
set
{
p_strServer = value;
this.ServerChanged(this,null);
}
}

public event System.EventHandler ServerChanged;

I'm getting errors when I hit this.ServerChanged(this, null);

And to fire it, is that going:

p_strServer = "NewServer"
this.ServerChanged;

?



Nicholas Paldino said:
Ryan,

Instead of naming your event SomeProperty_OnChange, name it
SomePropertyChanged. This will cause data bindings to update when you fire
the event.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

Ryan Ternier said:
I'm running a small C# app and I am trying to accomplish the following:

//Presentation Tier
txtMyTextBox.text = MyObject.SomeProperty;



//Business Tier

class MyObject
{
....
public string SomeProperty
{
....
}

public event System.EventHandler SomeProperty_OnChange;
....
}

What I want is when anything modifies the SomeProperty property, for the
PresentationTier to be pushed that data.

The class the SomeProperty belongs to runs many loops, and I want the
property text changing each time it hits a new loop to show the new data
in
the textbox without the Presentation Tier having to do any of the work.

I did this in VB a long time ago, and totally forget how to do it haha.

Any help would be very appreciated.
Click to expand...
Click to expand...
 
Ok I tried this,

In my Class I tried setting the Property by:
This.MyProperty = strURL[2];

MyProperty got the value of the string, but didn't throw back to my original
form.
My form load has the following code:

label1.DataBindings.Add(new Binding("Text",MyClass,"MyProperty"));

It still doesn't change on the form when the property changes in the class.


lblError.DataBindings.Add(new Binding("Text",objReminder,"ConnectedTo"));
 
Ryan,

You want to name your event ConnectedToChanged:

public event System.EventHandler ConnectedToChanged;

Then, you would fire the ConnectedToChanged event when the property
changed, like so:

public string ConnectedTo
{
get
{
return p_strServer;
}
set
{
p_strServer = value;

// You should check for null here, as you might not have any
listeners. You should
// Also pass EventArgs.Empty.
this.ConnectedToChanged(this, null);
}
}


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

Ryan Ternier said:
Ok,

I'm running:
public string ConnectedTo
{
get
{
return p_strServer;
}
set
{
p_strServer = value;
this.ServerChanged(this,null);
}
}

public event System.EventHandler ServerChanged;

I'm getting errors when I hit this.ServerChanged(this, null);

And to fire it, is that going:

p_strServer = "NewServer"
this.ServerChanged;

?



in
message news:[email protected]...
Ryan,

Instead of naming your event SomeProperty_OnChange, name it
SomePropertyChanged. This will cause data bindings to update when you fire
the event.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

Ryan Ternier said:
I'm running a small C# app and I am trying to accomplish the following:

//Presentation Tier
txtMyTextBox.text = MyObject.SomeProperty;



//Business Tier

class MyObject
{
....
public string SomeProperty
{
....
}

public event System.EventHandler SomeProperty_OnChange;
....
}

What I want is when anything modifies the SomeProperty property, for
the
PresentationTier to be pushed that data.

The class the SomeProperty belongs to runs many loops, and I want the
property text changing each time it hits a new loop to show the new
data
in
the textbox without the Presentation Tier having to do any of the work.

I did this in VB a long time ago, and totally forget how to do it haha.

Any help would be very appreciated.
Click to expand...
Click to expand...
Click to expand...
 
Yes that worked!

Thank you very Much.
Nicholas Paldino said:
Ryan,

You want to name your event ConnectedToChanged:

public event System.EventHandler ConnectedToChanged;

Then, you would fire the ConnectedToChanged event when the property
changed, like so:

public string ConnectedTo
{
get
{
return p_strServer;
}
set
{
p_strServer = value;

// You should check for null here, as you might not have any
listeners. You should
// Also pass EventArgs.Empty.
this.ConnectedToChanged(this, null);
}
}


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

Ryan Ternier said:
Ok,

I'm running:
public string ConnectedTo
{
get
{
return p_strServer;
}
set
{
p_strServer = value;
this.ServerChanged(this,null);
}
}

public event System.EventHandler ServerChanged;

I'm getting errors when I hit this.ServerChanged(this, null);

And to fire it, is that going:

p_strServer = "NewServer"
this.ServerChanged;

?



in
message news:[email protected]...
Ryan,

Instead of naming your event SomeProperty_OnChange, name it
SomePropertyChanged. This will cause data bindings to update when you fire
the event.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

I'm running a small C# app and I am trying to accomplish the following:

//Presentation Tier
txtMyTextBox.text = MyObject.SomeProperty;



//Business Tier

class MyObject
{
....
public string SomeProperty
{
....
}

public event System.EventHandler SomeProperty_OnChange;
....
}

What I want is when anything modifies the SomeProperty property, for
the
PresentationTier to be pushed that data.

The class the SomeProperty belongs to runs many loops, and I want the
property text changing each time it hits a new loop to show the new
data
in
the textbox without the Presentation Tier having to do any of the work.

I did this in VB a long time ago, and totally forget how to do it haha.

Any help would be very appreciated.
Click to expand...
Click to expand...
Click to expand...
 
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