calling an application from other application

Question

hello,

I am writing an application in Objective-C whose functionality is to call and execute another application.Pls can i know the procedure???Let me also know where i need to keep the calling application which has to load and execute???

Answer 1

I'm not sure I fully understand your question, but if all you're trying to do is launch another app, there are a number of ways to do this. The most straightforward is probably by using the NSTask class. Here is a simple example of launching iCal from within an Objective-C application using an NSTask.

NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/Applications/iCal.app/Contents/MacOS/iCal"];
[task launch];
[task release];

Answer 2

See the -launchApplication: method of the NSWorkspace class.

Answer 3

It is worth noting at this point that you are unlikely to be able to launch another application on the iPhone; the best you can do is probably detaching to another app; and even that might be nontrivial. (On the iPhone, 3rd party/userland applications cannot live in the background.)

Answer 4

The only way to "launch" another application is if the other application "cooperates" with yours, if you will.

The cooperation comes in the form of a URL protocol scheme that an application exposes. Examples are mailto: (exposed by the system mail application) and sms: (exposed by the Messages app).

http://wiki.akosma.com/IPhone%5FURL%5FSchemes seems to have a comprehensive list of third party apps exposing a custom protocol scheme that you can make use of.

Launching another app is a matter of calling [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"twitterrific://..."]; (for example).

As of OS 3.0 you can also check if a given URL protocol scheme is available via UIApplication's -canOpenURL: — checking if some app has registered the protocol scheme, or in other words checking if an application is installed.

If you are writing both apps yourself then launching a custom protocol scheme is pretty simple, however you can't launch an arbitrary iPhone app, and you wouldn't be able to enumerate available apps anyway because of the sandbox.