(IPhone/iPad Development) How to Determine the first ios app startup

Find the "application: didfinishlaunchingwitexceptions:" method in appdelegate. m and add the following code:

If (! [[NSUserDefaults standardUserDefaults] boolForKey: @ "everLaunched"]) {
[[NSUserDefaults standardUserDefaults] setBool: YES forKey: @ "everLaunched"];
[[NSUserDefaults standardUserDefaults] setBool: YES forKey: @ "firstLaunch"];
}
Else {
[[NSUserDefaults standardUserDefaults] setBool: NO forKey: @ "firstLaunch"];
}

The general solution is to use two keys: @ "everLaunched" to determine whether the user has logged on before,

@ "FirstLaunch" is used to determine other parts of the program.

When the key @ "everLaunched" is started for the first time, the key @ "everLaunched" will not be assigned an address and is set to YES. @ "firstLaunch" to YES.
Use the following code to determine other parts of the program:

If ([[NSUserDefaults standardUserDefaults] boolForKey: @ "firstLaunch"]) {
// Determine whether it is the first time

UIAlertView * alert = [[UIAlertView alloc] initWithTitle: @ "First time"
Message: @ "Enter App"
Delegate: self
CancelButtonTitle: @ "I know"
OtherButtonTitles: nil];
[Alert show];
[Alert release];

}
The first code running key @ "firstLaunch" will be set to NO.

 

It has been tested. The above method is more effective and easier than I thought.

 

From andy Pan's column