當UITextField文本改變時, 根據內容更新數據, 通過寫監聽事件即可.
添加監聽:

[timesField addTarget:self
               action:@selector(textFieldDidChange:)
     forControlEvents:UIControlEventEditingChanged]; // 監聽事件

監聽事件:

// 監聽改變按鈕
- (void) textFieldDidChange:(UITextField*) sender {

    // 文本內容
    NSInteger times = [sender.text integerValue];
    [_serviceNumList replaceObjectAtIndex:_servicePos withObject:[NSNumber numberWithInteger:times]];

    // 總價
    _totalPrice = (float)([_goodsList[_servicePos][@Price] floatValue]/100.0)*[[_serviceNumList objectAtIndex:_servicePos] integerValue];
    [_totalPriceLabel setText:[NSString stringWithFormat:@%0.1f, _totalPrice]];
}

其余UITextField屬性:

        // 輸入框
        UITextField *timesField = [[UITextField alloc] initWithFrame:CGRectMake(200*kViewRatio, 10*kViewRatio, 32*kViewRatio, 20*kViewRatio)]; // 位置大小
        [timesField setBorderStyle:UITextBorderStyleRoundedRect]; //外框類型
        NSAttributedString* timesText =[[NSAttributedString alloc] initWithString:[NSString stringWithFormat:@%ld, (long)[[_serviceNumList objectAtIndex:row] integerValue]]]; // 設置文字
        [timesField setAttributedText:timesText];
        [timesField setFont:[UIFont systemFontOfSize: 12*kViewRatio]]; // 文字大小
        [timesField setTextAlignment:NSTextAlignmentCenter]; // 文字位置
        [timesField setDelegate:self]; // 限制長度
        [timesField addTarget:self
                       action:@selector(textFieldDidChange:)
             forControlEvents:UIControlEventEditingChanged]; // 監聽事件
        [itemView addSubview:timesField]; // 添加父視圖