关于UItableview中的UITextfield的问题

用tableview做登陆， 手机号，验证码 当在cell2中点击获取验证码的button时，button的响应函数中取第一行的cell中的UItextField时是空的，创建UITextField的代码如下，
UITextField *passWordEdit = [[UITextField alloc] initWithFrame:CGRectMake(80 + PASSWORD_LEFTRANGE, 0, SCREEN_WIDTH - 80 - PASSWORD_LEFTRANGE, row.rowHeight)];
passWordEdit.backgroundColor = [UIColor clearColor];
passWordEdit.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
passWordEdit.keyboardType = UIKeyboardTypeDefault;
// passWordEdit.placeholder = @" 密 码 :";
// userNameEdit.text = [[NSUserDefaults standardUserDefaults] objectForKey:@"lastTelephoneNumber"];
passWordEdit.borderStyle = UITextBorderStyleNone;
passWordEdit.delegate = self;
passWordEdit.secureTextEntry = YES;
passWordEdit.clearButtonMode = UITextFieldViewModeAlways;
passWordEdit.tag = 52303;
self.passWordField = passWordEdit;
其中self.passWordField是类的成员变量，但是在button的响应函数中打印self.passWordField的地址的时候是空，大家看看是为什么呢。