只包含每个重复

Question

中的第一个的Linq Key必须将列表投递到我的应用程序中的字典，但即时通讯出现错误，指出“具有相同密钥的项目已被添加”。 我需要第一密钥和他的值

Dictionary<string, string> cells = 
      (from cell in sheet.Cells["A1:J20"] 
      where cell.Start.Column == 1 && cell.Value != null 
      select sheet.Cells[cell.Start.Row, 1, cell.Start.Row,9].Value) 
      .Cast<object[,]>() 
      .Distinct().ToDictionary(k => Convert.ToString(k[0, 2]), v => 
      Convert.ToString((v[0, 8]))); 

例Excel中：

• 键 =>值

• 键1 =>值1

• 密钥2 => Value2
• 密钥3 =>值3
• 密钥3 =>值4
• 密钥3 =>值5
• 键6 => Value6
• KEY7 => Value7
• Key23 => Value8

EDIT

Dictionary<string, string> dict = new Dictionary<string, string>(); 

        var cells = (from cell in sheet.Cells["A1:B16"] 
           where cell.Start.Column == 1 && cell.Value != null 
           select sheet.Cells[cell.Start.Row, cell.Start.Column, cell.Start.Row, 2].Value) 
                 .Cast<object[,]>(); 

周期，并添加到字典：

foreach (var i in cells) { 
         if (dict.ContainsKey(Convert.ToString(i[0, 0])) == false) 
          dict.Add(Convert.ToString(i[0, 0]), Convert.ToString(i[0, 1])); 
         // dict.Distinct(); 

        } 

但我需要在LINQ代码！

Answer 1

我决定我的问题

Dictionary<string, string> dict = (from cell in sheet.Cells["A1:B34"] 
           where cell.Start.Column == 1 && cell.Value != null 
           select sheet.Cells[cell.Start.Row, cell.Start.Column, cell.Start.Row, 2].Value) 
                 .Cast<object[,]>() 
                 .GroupBy(k => Convert.ToString(k[0,0])) 
                 .Select(k => k.First()) 
                 .ToDictionary(k => Convert.ToString(k[0, 0]), v => Convert.ToString(v[0, 1])) 

Answer 2

警告：未经测试的代码，我不能很容易地创建一个测试环境：

Dictionary<string, string> cells = 
     (from cell in sheet.Cells["A1:J1"] 
     where cell.Value != null 
     let key = sheet.Cells[cell.Start.Row, 3].Value.ToString() 
     let val = sheet.Cells[cell.Start.Row, 9].Value.ToString() 
     group val by key into vg 
     select new { vg.Key, Val = vg.FirstOrDefault() }) 
     .ToDictionary(k => k.Key, v => v.Val); 

此外，优化了很多，似乎怀疑我。