TableView UISearchBar Crashes while Searching

[vksmaini]

I've been playing around with a search facility for my application table view for a while now trying to get it working but i keep getting the same error in my console.

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: ' [NSCFDictionary rangeOfStringptions:]: unrecognized selector sent to instance

DataSource is an array which is taking itz value from a dictionary.... and tableData will be storing data that will be displayed in table.

Q: Suppose I have a dictionary with 5 values each having different keys corresponding to those values.. then i put that dictionary in an array. Can that array be used as a dataSource for search? and i am using the same array in cellForRowAtIndexPath to display data on my cells.

Plz suggest with code snippet.

Here is my code for textDidChange

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
    {   
        [tableData removeAllObjects];// remove all data that belongs to previous search

        if([searchText isEqualToString:@""]){
            searchText==nil;
            [tableview reloadData];     
            return;     
        }

        NSInteger counter = 0;  
        for(NSString *name in dataSource)       
        {       
            NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init];      
            NSRange r = [name rangeOfString:searchText options:NSCaseInsensitiveSearch];        
            if(r.location != NSNotFound)            
            {           
                if(r.location== 0)//that is we are checking only the start of the names.                
                {               
                    [tableData addObject:name];             
                }           
            }       
            counter++;      
            [pool release];     
        }   
        [tableview reloadData]; 
    }