如何重新加载表格视图？ Xcode 11

编程问答 2022-08-22

问题描述

我当前正在尝试向tableView添加一行，我添加视图的代码如下

     @IBAction func done(segue:UIStoryboardSegue) {
        let newContact = segue.source as! NewContactViewController
        FirstName = newContact.firstName
        LastName = newContact.lastName
           print("Adding the name: " + FirstName + " " + LastName + " to the nameArry")
        nameArry.append(FirstName + " " + LastName)
        print("Added " + nameArry[nameArry.count - 1] + " to name array")
        
        let indexPath = IndexPath(row: myContact.count + contacts.count - 1,section: 0) // Set the indexPath to the lowest part of the array
        
        tableView.beginUpdates() // Starts the update
        tableView.insertRows(at: [indexPath],with: .automatic) // Insert row at the lowest part of the table
        tableView.endUpdates() // Ends the update
        
        newContact.firstName = "" // Clears the variable "firstName"
        newContact.lastName = "" // Clears the variable "lastName"
        view.endEditing(true) // disables Editing,saw it on youtube.
    }

我将myContact.count + contacts.count用于indexPath，因为那是我在tableView上使用的

    // Get Number of items in table
    func tableView(_ tableView: UITableView,numberOfRowsInSection section: Int) -> Int {
        return (myContact.count + contacts.count)
    }

我收到以下错误：

Thread 1: Exception: "attempt to insert row 4 into section 0,but there are only 4 rows in section 0 after the update"

解决方法

为什么要删除一个？

library(dplyr)

df %>%
   janitor::adorn_totals() %>%
   mutate(across(.fns = as.character)) %>%
   #mutate_all in `dplyr` < 1.0.0
   #mutate_all(as.character) %>%
   tidyr::pivot_longer(cols = starts_with('Col'))

   
# A tibble: 12 x 4
#   Name  Date       name  value
#   <chr> <chr>      <chr> <chr>
# 1 John  23/04/2020 Col1  27   
# 2 John  23/04/2020 Col2  26   
# 3 John  23/04/2020 Col3  red  
# 4 Marco 23/04/2020 Col1  30   
# 5 Marco 23/04/2020 Col2  25   
# 6 Marco 23/04/2020 Col3  blue 
# 7 Tony  23/04/2020 Col1  56   
# 8 Tony  23/04/2020 Col2  45   
# 9 Tony  23/04/2020 Col3  green
#10 Total -          Col1  113  
#11 Total -          Col2  96   
#12 Total -          Col3  -

....写这行而不要像这样减去1 ... 

let indexPath = IndexPath(row: myContact.count + contacts.count - 1,section: 0)

因为如果要添加一行并从总数中减去它...那么更新后现有部分中包含的行数等于更新前该部分中包含的行数

,

我弄清楚了，我没有得到准确的计数，因为我没有在联系人数组中添加任何内容。

contacts.append(Contacts(MyContact: nameArry[nameArry.count - 1],Me: ""))

let indexPath = IndexPath(row: myContact.count + contacts.count - 1,section: 0)
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