Ios 如何将sqlite3表分配给nsarray

我正在开发一个聊天应用程序，我正在使用sqlite存储和检索聊天历史，我能够插入值，但在检索时，我在数组中得到nil，这是我的代码

messageArray=[DBObject AllRowFromTableName:@"chatTable" withUserID:myJID withFriendID:chatWithUser];


for (int i=0; i<[messageArray count]; i++) {

    Message *msg=[[Message alloc] init];
          msg.text=[[messageArray objectAtIndex:i] msg];
    if ([[messageArray objectAtIndex:i] lft_rght]==0) {
        msg.fromMe=YES;
    }
    else{
        msg.fromMe=NO;
    }

    msg.type=SOMessageTypeText;

    NSString *dateString =[[messageArray objectAtIndex:i] tim_dte];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"HH:mm,yyyy/MM/dd"];
    NSDate *dateFromString = [[NSDate alloc] init];
    dateFromString = [dateFormatter dateFromString:dateString];
    msg.date=dateFromString;

    [self.chatHistoryArray addObject:msg];

---

我收到msg.text empty。请在处理返回数组的循环中帮助我，这些行

Message *msg=[[Message alloc] init];
msg.text=[[messageArray objectAtIndex:i] msg];

应该是

Message *msg=[[Message alloc] init];
msg.text=[[messageArray objectAtIndex:i] text];

您还应该在循环之外创建一次NSDateFormatter，并使用它，因为它不是要创建的“快速”对象

您可能还需要重构对

[messageArray objectAtIndex:i]

的常量调用。创建一个局部变量，该局部变量只获取一次引用，然后使用该局部变量。所以重构后的代码看起来像

messageArray=[DBObject AllRowFromTableName:@"chatTable" withUserID:myJID withFriendID:chatWithUser];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"HH:mm,yyyy/MM/dd"];

for (int i=0; i<[messageArray count]; i++) {
    Message * baseMessage = [messageArray objectAtIndex:i];
    Message *msg=[[Message alloc] init];
    msg.text= baseMessage.text;
    msg.fromMe= (baseMessage.left_rght == 0);
    msg.type=SOMessageTypeText;
    msg.date=[dateFormatter dateFromString:baseMessage.tim_dte];

    [self.chatHistoryArray addObject:msg];
}

messageArray=[DBObject AllRowFromTableName:@“chatTable”with userid:myJID with friendid:chatWithUser]；
NSDateFormatter*dateFormatter=[[NSDateFormatter alloc]init]；
[日期格式化程序setDateFormat:@“HH:mm，yyyy/mm/dd”]；
对于（int i=0；i您似乎没有返回您创建的
数组
？准备工作也确实有效吗？注释掉的NSLog“IN-LOOP”在未注释掉时触发了吗？
messageArray=[DBObject AllRowFromTableName:@"chatTable" withUserID:myJID withFriendID:chatWithUser];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"HH:mm,yyyy/MM/dd"];

for (int i=0; i<[messageArray count]; i++) {
    Message * baseMessage = [messageArray objectAtIndex:i];
    Message *msg=[[Message alloc] init];
    msg.text= baseMessage.text;
    msg.fromMe= (baseMessage.left_rght == 0);
    msg.type=SOMessageTypeText;
    msg.date=[dateFormatter dateFromString:baseMessage.tim_dte];

    [self.chatHistoryArray addObject:msg];
}