Develop Reference

ASP.NET - How to check if one or more field values have been changed

I have a web form where I register a new employee. There're 3 parts in the form: Personal info, Address info, Special Status. But there's only one button for the whole form. When I submit the form all the information is updated to the database. So three Update statements are executed against the database. The methods are UpdatePersonalInfo, UpdateAddressInfo and UpdateSpStatus. Is there a way to check if there's been a change in any field in the certain part and run update method only if it's true. So something like this:
if (There's been any change to the personal data of the employee)
{
UpdatePersonalInfo;
}
if (There's been any change to the address information of the employee)
{
UpdateAddressInfo;
}
Sure I know, I can save all the previous values in a session object in PageLoad and then compare them one by one before running the method. But I thought maybe there's a magic way of doing this more easily.

Not sure that this is a better solution than any of the alternatives you already mentioned, but you could create a default handler to attach to the TextChanged, SelectedIndexChanged, etc events of your controls to keep track of which ones have changed.
List ChangedControls = new List(Of, String);
private void ChangedValue(object sender, System.EventArgs e) {
WebControl cntrl = (WebControl) sender;
ChangedControls.Add(cntrl.ID);
}
Then on your button click scour the ChangedControls list for the relevant controls.

Reopen Silverlight AutoCompleteBox popup without reloading suggestions from webservice

I have an AutoCompleteBox binded to an ObservableCollection ItemsSource which I filter on my own by querying entities from a domainservice.
I used the scenario of populating from a webservice call from the blog of Jeff Wilcox, by setting the PopulatingEventArgs.Cancel to True, and when my collection is ready, I call PopulateComplete() on the ACB.
My goal is to reopen the dropdown on mouseover (or click) but without reloading again all the data from the web. I found a question on stackoverflow where the answer was to set IsDropDownOpen to True. But in this case, the ACB population starts again, and another call goes to the webservice.
Of course, when the user starts typing, the filtering should be done again.
(for ex. you type "ric" and the box suggests "rice" and "ricin", you select rice, but you change your mind and want to select another one from the same collection, lets say "ricin". In this case you already have the suggestions containing "ric" in memory, no need to load them again..)
I found an alternative way in which instead of setting IsDropDownOpen, I just simply call the PopulateComplete() method. This does exactly the same thing that I want, but with a little fail: after my ACB loses focus, the dropdown is not opened again on mouseover liek it should. Even when I click back into the acb textbox.
So is there a fix for this, or does someone know why the PopulateComplete() only reopens the dropdown when the ACB has focus for the first time? Or this was only my luck that calling this method reopened the dropdown and the IsDropDownOpen property should be used instead (afaik this would be only possible with some flags indicating that its a fake populating event triggered by my mouseover and after PopulatingEventArgs.Cancel i should call immediately PopulateComplete. but i dont get it, if this may work (haven't tried yet), why not when calling simply the PopulateComplete)?

Well, I tried the IsDropDownOpen with a testing bit, and almost worked:
private void FoodBox_MouseEnter(object sender, MouseEventArgs e)
{
//FoodBox.PopulateComplete(); not working after acb loses focus...
testbit = true;
FoodBox.IsDropDownOpen = true;
}
Here's the overloaded Populating method (no need for setting ItemsSource explicit because its bound to an ObservableCollection):
public void FoodBox_Populating(object sender, PopulatingEventArgs e)
{
e.Cancel = true;
if (!testbit)
{
VM.LoadFoodSuggestions(FoodBox.SearchText);
}
else
{
testbit = false;
FoodBox.PopulateComplete();
}
}
This works good so far, execpt that the search does not start because when (for the first time) you mouseover and select the acb, it sets the testbit to true.
So I added another event handler that takes care of setting the testbit to false every time the user inputs text on the keyboard, ensuring that the suggestions are regenerated/reloaded after SearchText is modified by the user, but not when you select an item from the dropdown:
private void FoodBox_TextChanged(object sender, RoutedEventArgs e)
{
testbit = false;
}
I still don't know why calling PopulateComplete() isn't enough without setting the IsDropDownOpen to Ture, and setting that to true, also delays the dropdown opening approximately with the time specified in the MinimumPopulateDelay, but at least it gives me the functionality I wanted. (Maybe digging into the source of acb would answer this mistery)
Maybe this functionality implemented in the basic acb would be helpful in a future release of the control.

How to distinguish between User Control load on form and load when runtime

I created a user control using C# for windows form application. This user control has some properties. In runtime, if the user does not enter values for this properties I want to show a message box and exit the application.
The problem is when I write the checking code in the Load event of User Control. When I drag & drop it on the form the message box will appear.
private void UserControl1_Load(Object sender, EventArgs e)
{
if (_getFirstPageArgument==null || _getFirstPageArgument.Length==0)
{
throw new Exception("Some Message");
}
}
How do I distinguish between load on the form and load on run time?

I fear there is a larger problem here. But to solve your immediate problem (if I understand correctly...) There is a form attribute called DesignMode. When you are in the visual studio design mode, this will be true. At runtime, this will be false.

For beginners, #Nimas case can be a good study point to understand that Visual Studio actually runs and executes parts of our code even when we are in design time, which is why the constructor is invoked. Even "DesignMode" property is not 100% reliable. You can find an interesting note here related to that http://weblogs.asp.net/fmarguerie/archive/2005/03/23/395658.aspx

If you only want to know when the type itself has been loaded into the runtime (not a specific instance), you can put code into the static constructor for that class.
If I'm misinterpreting your question, please clarify using a timeline when you want specific events to happen.

Unable to Affect Scintilla Control Programmatically at Runtime

I'm attempting to use the ScintillaNET control in an application I am working on. I drag and drop the control into my form and run form. The control appears on the form. This is good. In addition, if I set any of the properties in the control's properties editor (ConfigurationManager.Language, for example), I am able to type in that language and see syntax highlighting occur.
Where I run into problems is when I attempt to change properties programmatically. For example, I attempt to load text from a file into the form (I'm doing this in the form's Load). The text doesn't display. I also can't seem to show the line numbers or do any other number of tasks (including programmatically change the Language).
Any idea what I may be doing wrong? Even something as simple as the code below doesn't seem to work:
private void scintilla1_Load(object sender, EventArgs e)
{
scintilla1.ConfigurationManager.Language = "xml";
}

Simply add scintilla1.ConfigurationManager.Configure();
private void scintilla1_Load(object sender, EventArgs e)
{
scintilla1.ConfigurationManager.Language = "xml";
scintilla1.ConfigurationManager.Configure();
}

After spending some time playing around with the different events, it appears that I cannot affect the Scintilla control until after it is already visible. Hence, the "Load" event does not let me make any programmatic changes to the control until I've set it visible.
It's a little strange, and seems sort of pointless to me to have the Load event at all, but I just wanted to let everybody know what is happening in case someone else ran into the same problem.

Problem changing values in textbox

Simplifying
I have a text box and a button
The button just create an messagebox with the text from the textbox.
But i change the value of the textbox, the new value apears (Ex: Type 123) but the message box does not show the value.
If i try to use the value in the programming (get the value by textbox1.text) the variable has nothing ( textbox1.text = "") but i can still see what i typed in the form.
Anyone has any clue?

Your button's click event handler should look something like this
private void button_Click(object sender, EventArgs e)
{
MessageBox.Show(textBox.Text);
}
I suspect you already have code similar to this and that at some point the textbox is cleared or otherwise set to String.Emppty but without seeing actual code it is difficult to help you

When/where did you check the value of textBox1.Text? If you're checking it in the constructor, Form1_Load, or anything else that occurs before you'll have typed text, you will get an empty value.
To properly check the value of textBox1.Text, you should set what's called a breakpoint on the line that calls MessageBox.Show(textBox1.Text). To do this, click in the grey area of the source editor (it's on the far left) on the line containing MessageBox.Show(..). A red circle will appear and your code should be highlighted. When you run your application and click on your button, your application should pause and Visual Studio will highlight that line and from here you can hover over "textBox1.Text" in the MessageBox.Show() line and it should show you the current value.
If your application is as simple as a form, a textbox, and your button1_Clicked event handling code, this should work no problem. If it is not this simple, then you need to look for anything that sets the value of the textBox in your code and make sure it isn't passing any blank values by using breakpoints.
To solve this properly, though, we really need more information.

Thanks Eric and Crippledsmurf. As both of you said, its hard to help without the code.
The problem I found is that when calling the form, I send some objects by reference, so I can track them down and I found that when (don't ask me why it happens that way, I'm still working on it) the construtor is called he make an new component, so the component in the interface no longer represents the one pointed by the variable "textbox1" (Yes Crash893, I haven't mispelled the name).
I found that I was making some mess with the references, and probably that was causing the problem. I fixed the problem by changing the actions performed by references for delegates and events, but I couldn't track down the exactly source of the problem.
Thanks, again, everyone for the insights.