使用while循环时显示多个结果行，而不是一行

本文关键字：一行 使用 循环 显示 结果 while | 更新日期: 2023-09-27 18:22:02

以下是行为摘要：当循环迭代到记录集的末尾时，检索值。然后，值将显示在它们各自的位置。

问题是，我只想显示一组值。使用while可以显示与要查询的表中的记录一样多的值。下面的示例：

应显示的内容：

<div>
    <div>Service One is Stopped</div>
    <div>Service Two is Running</div>
    <div>Service Three is Stopped</div>
</div>

实际情况：

<div>
    <div>Service One is </div> 
    <div>Service Two is Running</div>
    <div>Service Three is </div>
    <div>Service One is </div>
    <div>Service Two is </div>
    <div>Service Three is Running</div>
    <div>Service One is Stopped</div>
    <div>Service Two is </div>
    <div>Service Three is </div>
</div>

以下是违规代码。如果这是一个微不足道的问题，我深表歉意。我正在摆脱两年多不写代码的习惯，有时甚至是简单的事情也会让你：-）。非常感谢您的帮助！！！

@using System.Configuration;
@using System.Data.SqlClient;
@using System.Data;
@using System.Linq;
@{
  System.Data.SqlClient.SqlConnection cn = null;
  cn = new System.Data.SqlClient.SqlConnection(ConfigurationManager.ConnectionStrings["sqlConn"].ToString());
  cn.Open();
  System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand("SELECT DISTINCT * FROM servicehealth", cn);
  var myreader = cmd.ExecuteReader();
}
@{
int rowCount = 0;
}
@while (myreader.Read())
{
        rowCount++;
        string service1status = "";
        string service2status = "";
        string service3status = "";
        string servicename = @myreader["servicename"].ToString();
        switch (servicename.ToLower())
        {
            case "serviceone":
                service1status = @myreader["servicestate"].ToString();
                break;
            case "servicetwo":
                service2status = @myreader["servicestate"].ToString();
                break;
            case "service3":
                service3status = @myreader["servicestate"].ToString();
                break;
        }
<div>
    <div>Service One is @service1status</div>
    <div>Service Two is @service2status</div>
    <div>Service Three is @service3status</div>
</div>
}

编辑：以下是有问题的表格的缩写：

ServiceId                   |  ServiceName  |   ServiceState  |  StartTrackTime  |  LastUpdated
1111-11111-111111-11111111  |  ServiceOne   |   Stopped       |  1/30/2012 0:00  |  1/30/2012 17:57
2222-22222-222222-22222222  |  ServiceTwo   |   Running       |  1/30/2012 0:00  |  1/30/2012 17:57
3333-33333-333333-33333333  |  ServiceThree |   Running       |  1/30/2012 0:00  |  1/30/2012 17:57

使用while循环时显示多个结果行，而不是一行

看起来您可以在while的每次迭代中输出服务及其状态，并将其放置在包含的div标记之间。您应该为找到的每项服务获取一条线路。

<div>
@while (myreader.Read())
{
     string servicestatus = servicestatus = @myreader["servicestate"].ToString();
     string servicename = @myreader["servicename"].ToString();
    <div>@servicename is @servicestatus</div>
}
</div>

您需要将字符串声明和div标记移动到while循环之外：

@{
int rowCount = 0;
string service1status = "";
string service2status = "";
string service3status = "";
while (myreader.Read())
{
    rowCount++;
    string servicename = @myreader["servicename"].ToString();
    switch (servicename.ToLower())
    {
        case "serviceone":
            service1status = @myreader["servicestate"].ToString();
            break;
        case "servicetwo":
            service2status = @myreader["servicestate"].ToString();
            break;
        case "service3":
            service3status = @myreader["servicestate"].ToString();
            break;
    }
}
}
<div>
    <div>Service One is @service1status</div>
    <div>Service Two is @service2status</div>
    <div>Service Three is @service3status</div>
</div>
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