Dynamically calling a method with parameters

Question

I know it's possible to call a method by its name like this:

 NSString *string =@"methodName";
[self performSelector:NSSelectorFromString(string)];

And that it will execute the method below:

-(void)methodName
   {
              // todo:.....
   }

I'm wondering how to call a method which has parameters like this:

-(void)methodName:(NSString *)_name :withValue (NSString *) value
     {
              // todo:.....
     }

onevcat · Accepted Answer · 2012-12-28T04:58:07.120

2

You can use -performSelector:withObject:

NSDictionary *dic = @{@"name":@"stringName",@"value":@"12"};

NSString *string =@"methodName:";
[self performSelector:NSSelectorFromString(string) withObject:dic];

And in -methodName:

-(void) methodName:(id)obj
{
    NSDictionary *dic = (NSDictionary *)obj;
    [self methodName:dic[@"name"] withValue:dic[@"value"]];
}

edited Dec 28 '12 at 04:58

answered Dec 28 '12 at 04:49

onevcat

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i cant directly pass the arguments to the method? – Lochana Ragupathy Dec 28 '12 at 05:00
Yes, it is impossible by performSelector, as I know. You can refer to [this answer](http://stackoverflow.com/questions/8439052/ios-how-to-implement-a-performselector-with-multiple-arguments-and-with-afterd) for some detail. Maybe you could try dispatch if you really want multiple parameters. – onevcat Dec 28 '12 at 05:06
i go with your answer and it worked for me and better to have a dictionary while passing the args with the help of key while coding dynamically thanks onevcat – Lochana Ragupathy Dec 28 '12 at 05:18

score 2 · Answer 2 · answered Dec 28 '12 at 05:06

2

I don't know the exact syntax off the top of my head, but you can do this with NSInvocation.

answered Dec 28 '12 at 05:06

Michael Mior

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For who needs it an example here: http://stackoverflow.com/questions/11477951/comparing-two-strings-through-a-selector-unexpected-result , it also explains how to take the return value. – Ramy Al Zuhouri Dec 28 '12 at 05:10

Zen · Answer 3 · 2012-12-28T05:18:40.407

Well I dont know what exactly is needed but from my understanding , it is something like :

NSArray *fruits = [NSArray arrayWithObjects:@"Apple", @"Mango", nil]; 
NSArray *drinks = [NSArray arrayWithObjects:@"Drink1", @"Drink2",nil];
[self serveOrdersWith:fruits andDrinks:drinks];

Somewhere in the class , the method will be called with the argument array fruits i.e.

-(NSArray*)serveOrdersWith :(NSArray*)array1 andDrinks:(NSArray*)array2{
     //Your code here but I will finish with this only
    NSArray *orderArray;
    [orderArray addObject:array1];
    [orderArray addObject:array2];
    return orderArray;
}

Dynamically calling a method with parameters

3 Answers3