Question

我有一席之地,一开始便宣布“价值”为NSObject,然后在“价值”内实际生成开关说明。 “价值”可以是NSNumber、NSDate、NSData、NSString或Nil。这是法典:

for (int i = 0; i < self.columnCount; i++) {
  NSObject *value;
  switch (mysql_fields[i].type) {
    case ...
      ...
    case MYSQL_TYPE_LONG:
      value = [[NSNumber alloc] initWithInt:atoi(row[i])];
      /* [value autorelease]; */  // 2)
      break;
    case MYSQL_TYPE_DECIMAL:
      NSString *decimal = [[NSString alloc] initWithCString:(char *)row[i] encoding:NSUTF8StringEncoding];
      value = [[NSDecimalNumber alloc] initWithString:decimal];
      /* [value autorelease]; */  // 2)
      [decimal release];
      break;
    case ...
      ...
  } // end of switch
} end of for
Field *field = [[[Field alloc] initWithRecord:record] autorelease];
/* [value autorelease]; */  // 3)
[field setValue:value forKey:@"value"];
/* [value release]; */  // 4)

现在我不知道如何释放“价值”。这是我所尝试的,相应的X代码4“Analyzer”电文:

no release -> "potential leak"
[value autorelease] after alloc/init within each case statement -> "object sent autorelease too many times"
[value autorelease] directly before the last use -> "object sent autorelease too many times"
[value release] after the last use -> "Incorrect decrement of the reference count of an object not owned by the caller at this point"

Answer 1

只有在分配物体时,才会自动释放:

value = [[[NSNumber alloc] initWithInt:atoi(row[i])] autorelease];
// ....
value = [[[NSDecimalNumber alloc] initWithString:decimal] autorelease];

Answer 2

您是在休息室内宣布<代码> 数值,因此,您必须将其“AFTER”改为“INSIDE” 。

for (int i = 0; i < self.columnCount; i++)
{
    NSObject *value;
    switch (mysql_fields[i].type)
    {
        case ...
            ...
        case MYSQL_TYPE_LONG:
            value = [[NSNumber alloc] initWithInt:atoi(row[i])];
            break;
        case MYSQL_TYPE_DECIMAL:
            NSString *decimal = [[NSString alloc] initWithCString:(char *)row[i] encoding:NSUTF8StringEncoding];
            value = [[NSDecimalNumber alloc] initWithString:decimal];
            [decimal release];
            break;
        case ...
            ...
    }
    Field *field = [[[Field alloc] initWithRecord:record] autorelease];
    [field setValue:value forKey:@"value"];
    [value release];
}

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