Question

我需要找到一个代码，以便从列表框中的最小数字中减去最大数字。我添加了属性中的列表框项目，如果有人知道任何事情，请帮助我，我尝试了这段代码

  int lowestattendance = attenadances.Max();
  string lowestname = "";
  int index = 0;

   while (index < attenadances.Count) ;
   {
       if (attenadances[index] < lowestattendance)
       {
           lowestattendance = attenadances[index];
           lowestname = Names[index];
       }

       index++;
   }

   string message = string.Format(
     "the person with the lowest attendance is {0}" + "and his attendance is { 1}", 
      lowestname, 
      lowestattendance);

   MessageBox.Show(message, " lowest attendance");

它从未显示任何内容。

Answer 1

您正在寻找ArgMin功能;即使 Linq 没有这样的东西，你也可以在Aggregate的帮助下轻松实现它：

   using System.Linq;

   ...

   //TODO: typo - attendances, not attenadances 
   var lowest = attenadances
     .Select((value, index) => new {
        attendance = value,
        name = Names[index], })  
     .Aggregate((s, a) => s.attendance < a.attendance ? s : a);

   //DONE: { 1} should be {1}
   //DONE: can a woman be the top truant? - his/her 
   string message = string.Format(
     "the person with the lowest attendance is {0} and his/her attendance is {1}", 
      lowest.name, 
      lowest.attendance);

   //DONE: leading space eliminated
   MessageBox.Show(message, "lowest attendance");

如果您不想 Linq 但循环实施，我建议使用for而不是while：

  int lowestattendance = 0;
  string lowestname = null;

  for (int i = 0; i < Attenadances.Count; ++i) 
    // change min: on the very 1st item; if next item is less than current min
    if (i == 0 || attenadances[i] < lowestattendance) {
      lowestattendance = attenadances[i];
      lowestname = Names[i]; 
    } 

  string message = string.Format(
    "the person with the lowest attendance is {0} and his/her attendance is {1}", 
     lowestname, 
     lowestattendance);

  MessageBox.Show(message, "lowest attendance");

Answer 2

根据您发布的代码，格式化邮件时会收到FormatException。原因是您的占位符{ 1}不允许使用前导空格。

请更换格式化代码行

string message = string.Format(
    "the person with the lowest attendance is {0}" +
    "and his attendance is {1}", // change here from { 1} to {1}
    lowestname, lowestattendance);

如果您有其他问题，请在您的问题中更具体。

Answer 3

DonationsListFragment作为public void refreshDonations() { apiClient.donationCurrentDonations(); refreshLayout.setRefreshing(true); }循环可以更好地工作，就像这样

<?php
include("misc.inc");
session_start();
$connect = mysqli_connect($host,$user,$password,$database) or die ("Couldn't connect database");
$sql    =   "SELECT * FROM ad ORDER BY training_start desc";
$result =   mysqli_query($connect,$sql) or die("Couldn't execute query.");
echo    "<table cols='4'  cellspacing='25'>";
echo    "<th>ID</th>";
echo    "<th>Training Name</th>";
echo    "<th>Trainer Name</th>";
echo    "<th>Training Dates</th>";
echo    "<th>Registration Starts</th>";

while($row=mysqli_fetch_assoc($result))
{

extract($row );


echo    "<tr><td >$id</td>";
echo    "<td  ><a href='ad_details.php'>$training_name</a></td>";
echo    "<td >$trainer_name</td>";
echo    "<td >$training_start - $training_end</td>";
echo    "<td >$reg_start</td></tr>";

}

echo    "</table>";

?>

请注意我是如何删除分号的？

while变成for

这是因为多余的分号计为循环结束，因此计算机正在看

for (int i = 0; i < attenadances.Count; i++) { if (attenadances[i] < lowestattendance) { lowestattendance = attenadances[i]; lowestname = Names[i]; } }。因此，它永远不会做任何事情！

如何计算列表框中的两个数字

3 个答案: