Linq代码不能正常工作

本文关键字：工作 常工作 代码 不能 Linq | 更新日期: 2023-09-27 18:13:54

我编写了以下代码，以便在网格视图中将复选框选中(true)的所有行的列值"lblJurisdiction"组合在一起

if (grdView.Rows.Count > 0)
{
    foreach (GridViewRow row in grdView.Rows)
    {
        CheckBox chkbox = row.FindControl("chkbox") as CheckBox;
        Label lblJurisdiction = row.FindControl("lblJurisdiction") as Label;
        bool saveThis = chkbox.Checked;
        if (saveThis == true)
        {
            List<String> Items = new List<String>();
            Items.Add(lblJurisdiction.Text);
            Items.Sort();
            List<string> Unique = Items.Distinct().ToList();
            string ReplacedJurisdiction = string.Join(",", Unique.ToArray());
            hdnJurisdiction.Value = ReplacedJurisdiction;
        }
    }
}

例如，网格视图包含

  • [true] [Alabama] [some value]
  • [true] [Alaska] [some value]
  • [false] [New York] [some value]
  • [false] [California] [some value]

现在隐藏字段应该包含Alabama, Alaska它只合并了一个，即阿拉斯加…

Linq代码不能正常工作

你应该改变你的变量范围!您应该在foreach循环外声明列表，并在完成计算后设置值。我还修改了你的代码，以匹配c#中常见的命名和编码约定。

if (grdView.Rows.Count > 0)
{
    var states = new List<string>();
    foreach (GridViewRow row in grdView.Rows)
    {
        var chkbox = row.FindControl("chkbox") as CheckBox;
        if (chkbox.Checked)
        {
            var lblJurisdiction = row.FindControl("lblJurisdiction") as Label;
            states.Add(lblJurisdiction.Text);
        }
    }
    hdnJurisdiction.Value = string.Join(", ", states.Distinct().OrderBy(x => x));
}

您应该将字符串连接起来，现在您在隐藏字段

中覆盖它们
if(hdnJurisdiction.Value.Length > 0 && ReplacedJurisdiction != "")
   hdnJurisdiction.Value += ", ";
hdnJurisdiction.Value += ReplacedJurisdiction;

原始代码根本没有使用LINQ。选择所有选中行的标签的LINQ查询可以如下所示:

var labels= grdView.Rows.OfType<GridViewRow>() 
               .Where(row=>(row.FindControl("chkbox") as CheckBox)?.Checked)
               .Select(row=>(row.FindControl("lblJurisdiction") as Label)?.Text)
               .Distinct()
               .OrderBy(x=>x);

或this，以查询形式:

var labels=(from row in grdView.Rows.OfType<GridViewRow>()
            let chkbox = row.FindControl("chkbox") as CheckBox
            let label=row.FindControl("lblJurisdiction") as Label
            where chkbox.Checked            
            select label.Text)
           .Distinct().OrderBy(x=>x);

一旦你有了所有的标签，你可以把它们连接起来:

var text=String.Join(labels);
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