How to turn of the sound of App and not to turn off the sound of System in IPhone?

I know that I can turn off the sound of App and not to turn off the sound of System in Anddroid , but How to do in IPhone 开发者_StackOverflowby code , Thank you very much!

I don’t think there is an API switch for that, you have to write it yourself. If you just play sound effects you can have one separate class for that:

@interface SFX : NSObject {…}
- (void) playFooSound;
- (void) playBarSound;
@end

And this class would check internally if the sound switch is on before it plays anything:

- (void) playFooSound {
    if (!soundEnabled)
        return;
    …
}

There are many ways to do something similar depending on your situation.