memory leak when removing objects in NSMutableArray

Question

Hello everyone

I hope to store MYFileObj to NSMutableArray (fileArray) and display data on an UITavleView(tableview).

//----------------------------------MYFileObj
#import <UIKit/UIKit.h>


@interface MYFileObj :  NSObject  {

    NSString *fileName;

}

-(void) setFileName:(NSString *)s ;
-(NSString *) fileName ;


@end

the array I want to store data

NSMutableArray *fileArray;

I created new object and add to fileArray

MYFileObj *newobj=[[MYFileObj alloc] init ];
NSString *ss=[[NSString alloc] initWithFormat:@"%@",path]  ;
[newobj setFileName:ss];
[ss release];
[fileArray addObject:newobj];
[newobj release];

[atableview reloadData];

After the first time relaodData and do something, I want to reload fileArray and redraw atableview.

//code to remove all object in atableview
if([fileArray count]>0)
{  
   [fileArray removeAllObjects];
   [atableview reloadData];
}  

I notice that there are memory leak. I hope to know the method "removeAllObjects" removes only MYFileObj themselves or also removes MYFileObj's member property "fileName"?

Thanks

interdev

Answer 1

it depends how you implemented setFileName and dealloc in your MyFileObj class. Do you send a release message to fileName in dealloc ? Do you send it a retain in your setter ?

Answer 2

You do not state where you have detected the memory leak, but I'll assume from the posted code that you are not releasing the fileName in MyFileObj's dealloc method.

Answer 3

I got memory leak after removeAllobjects

the methods of MYFileObj

-(void) setFileName:(NSString *)s ;
{
    [fileName release];
    fileName= [s copy];
}
-(NSString *) fileName ;
{
        return [[fileName copy] autorelease];
}

Answer 4

A good practice is to use retain/release in the setter. This way you avoid unnecessary object creation/copy:

- (void)setFileName:(NSString *)s {
    [s retain]; // <- Retain new value
    [fileName release]; // <- Release old value
    fileName = s;
}

- (NSString *)fileName {
    return fileName;
}

- (void)dealloc {
    [fileName release]; // <- Release the instance
    [super dealloc];
}