查詢體必須與選擇子句或一組子句結束...的DataGridView

Question

誤差凸起

查詢體必須與選擇子句或一組子句結束

List<DataGridViewRow> selectedRows = 
    (from row in DataGridView1.Rows.Cast<DataGridViewRow>() 
    where Convert.ToBoolean(row.Cells("CheckBoxColumn").Value) == true).ToList(); 

Answer 1

你應該改變這種

from row in DataGridView1.Rows.Cast<DataGridViewRow>() 
where Convert.ToBoolean(row.Cells("CheckBoxColumn").Value) == true 

這個

from row in DataGridView1.Rows.Cast<DataGridViewRow>() 
where Convert.ToBoolean(row.Cells("CheckBoxColumn").Value) == true 
select row 

值得注意的是，你將有相同的結果，如果你在下面的語法寫整個查詢：

var selectedRows = DataGridView1.Rows 
           .Cast<DataGridViewRow>() 
           .Where(row => Convert.ToBoolean(row.Cells("CheckBoxColumn").Value) == true) 
           .ToList(); 

Answer 2

當寫在查詢語法LINQ查詢它必須有一個select clause它：

var result = from item in collection 
      select item; 

你的情況：

var result = (from row in DataGridView1.Rows.Cast<DataGridViewRow>() 
       where Convert.ToBoolean(row.Cells("CheckBoxColumn").Value) 
       select row).ToList(); 

請注意，做Convert.ToBoolean(row.Cells("CheckBoxColumn").Value) == true是多餘的，因爲Convert.ToBoolean(row.Cells("CheckBoxColumn").Value)已經是布爾值