Question

I’ve got a question. Where is the reason for EXC_BAD_ACCESS in the following code ?

-(void)restClient:(DBRestClient *)client loadedMetadata:(DBMetadata *)metadata {
    if(metadata.isDirectory) {
        db_Path = metadata.path;
        int i = 0;
        NSString *fileName = [[NSString alloc] init];
        for(DBMetadata *file in metadata.contents) {
            fileName = [NSString stringWithFormat:@"%@", file.filename];
            [db_MetaFileNames addObject:file.filename];
            i++;
        }
        [self createMetaListArray];   
        [fileName release];                   
    }
}

-(void)createMetaListArray {
    fileNamesAtDirectory = db_MetaFileNames;
    for (int i=0; i < [fileNamesAtDirectory count]; i++) {
        NSString *filePathWithName = db_directory;

        [filePathWithName stringByAppendingFormat:
            [fileNamesAtDirectory objectAtIndex:i]];

        [filePathsAtDirectory addObject:filePathWithName];
        [filePathWithName release];
   }
}

Can Anyone here help me ?

Answer 1

Here:

NSString *fileName = [[NSString alloc] init];
for(DBMetadata *file in metadata.contents) {
  fileName = [NSString stringWithFormat:@"%@", file.filename]; 

The NSString on the first line gets overwritten with the new values on the third line. The original value leaks.

This means that:

}
[self createMetaListArray];
[fileName release];   

The release on the last line releases not the fileName that you alloc/init above, but the assignment inside the loop. You don’t alloc/copy/retain that, so you’re not “in charge” of releasing it.

You have a similar misunderstanding in the second function.

[filePathWithName stringByAppendingFormat:[fileNamesAtDirectory objectAtIndex:i]];

This does not amend filePathWithName. It returns a new string.

I suggest you read up on Cocoa’s memory management rules — you’re missing some fundamentals. Understanding those will make your life a lot easier.