Question

在类似的问题中，我无法找到问题的解决方案。我使用fmdb包装器从sqlite数据库中提取了一大堆数据。我的fmdb实用程序类中的方法与此类似：

  - (NSMutableArray *) getConnectionsForKey: (NSString *) key
 {

     NSString *query = [NSString stringWithFormat:@"select * from user" ];



     FMResultSet *results = [database executeQuery:query];

     NSMutableArray *retArray = [[ NSMutableArray alloc ] init ];

     while ([ results next ]) {

         NSString *fname = [ results stringForColumn:@"firstname" ];
         NSString *lname = [ results stringForColumn:@"lastname" ];


         NSMutableDictionary *aDictionary = [[ NSMutableDictionary alloc ]
                                               init
                                             ];

        [ aDictionary  
          setObject:fname 
          forKey:@"firstname" 
        ]; 

       [ aDictionary 
        setObject:lname 
        forKey:@"lastname" 
       ];



       [ retArray addObject:aDictionary ];

       [ aDictionary release ];


}

[ results close ];

return retArray;
}

将我的信息存储在一系列词典中。在我的视图控制器中，我像这样调用我的方法：

 -(void) setCurrentConnections: (NSString *) key {

   if ( currentConnections != nil ) {
         [ currentConnections removeAllObjects ];
   }

   LocalDatabase *db = [[ LocalDatabase alloc ] init ];

   [ db openDatabase ];

   currentConnections = [ db getConnectionsForKey:key ];

   [ db closeDatabase ];
  [ db release ];


}

现在，每次我调用此方法来使用新联系人更新我的数组时，我都会有一致的泄漏，并且在我使用分配工具观察时会不断积累。即使我在从数据库加载后立即释放currentConnections并且从不再次调用此方法，这种情况也会发生，所以我怀疑它是数据库实现的东西。还有其他人处理过这个问题吗？

Answer 1

currentConnections在'setCurrentConnections'中泄漏。以下是我将如何修复它（注意我也改变了'getConnectionsForKey'来返回一个自动释放的对象）。

 - (NSMutableArray *) getConnectionsForKey: (NSString *) key
 {

     NSString *query = [NSString stringWithFormat:@"select * from user" ];
     FMResultSet *results = [database executeQuery:query];

     NSMutableArray *retArray = [[ NSMutableArray alloc ] init ];
     while ([ results next ]) {

         NSString *fname = [ results stringForColumn:@"firstname" ];
         NSString *lname = [ results stringForColumn:@"lastname" ];
         NSMutableDictionary *aDictionary = [[ NSMutableDictionary alloc ] init];

        [ aDictionary  
          setObject:fname 
          forKey:@"firstname" 
        ]; 

       [ aDictionary 
        setObject:lname 
        forKey:@"lastname" 
       ];

       [ retArray addObject:aDictionary ];
       [ aDictionary release ];


       }

[ results close ];

return [retArray autorelease];
}


 -(void) setCurrentConnections: (NSString *) key {

   [ currentConnections removeAllObjects ];
   [ currentConnections release];

   LocalDatabase *db = [[ LocalDatabase alloc ] init ];

   [ db openDatabase ];

   currentConnections = [ db getConnectionsForKey:key ];
   [currentConnections retain];

   [ db closeDatabase ];
  [ db release ];

}

您可以跳过removeAllObjects的来电，只需致电发布。原始代码中的问题是您覆盖了对现有currentConnection的引用而没有先释放它，因此导致泄漏。

正确使用FMDB /内存

1 个答案: