如何将选择新的LINQ转换为数据表 我需要使用Windows应用程序形式C＃比较多个文件。 我已经使用LINQ和Lambda表达式来总结重复项 请帮助谢谢
我见过Convert select new to DataTable?。并尝试
var firstRecord = records.First();
if (firstRecord == null)
return;
var infos = firstRecord.GetType().GetProperties();
DataTable table = new DataTable();
foreach (var info in infos) {
DataColumn column = new DataColumn(info.Name, info.PropertyType);
table.Columns.Add(column);
}
foreach (var record in records) {
DataRow row = table.NewRow();
for (int i = 0; i < table.Columns.Count; i++)
row[i] = infos[i].GetValue(record);
table.Rows.Add(row);
}
但是它的顺序错误，其中不包含任何元素。
这些是我的完整代码。
namespace Comparison2._0
{
public partial class ComparisonForm : Form
{
public class FlatFile
{
public string Location { get; set; }
public string Item_Type { get; set; }
public string Type { get; set; }
public double Amount { get; set; }
}
public ComparisonForm()
{
InitializeComponent();
}
private void UploadTransactionReportButton_Click(object sender, EventArgs e)
{
OpenFileDialog dialog = new OpenFileDialog();
dialog.Multiselect = false;
if (dialog.ShowDialog() == DialogResult.OK)
{
String path = dialog.FileName;
//String fileName = path.Substring(path.LastIndexOf("\\") + 1);
TransactionFileNameTextBox.Text = path;
}
}
private void UploadMovementReportButton_Click(object sender, EventArgs e)
{
OpenFileDialog dialog = new OpenFileDialog();
dialog.Multiselect = false;
if (dialog.ShowDialog() == DialogResult.OK)
{
String path = dialog.FileName;
//String fileName = path.Substring(path.LastIndexOf("\\") + 1);
MovementReportTextBox.Text = path;
}
}
private void UploadFlatfileReportButton_Click(object sender, EventArgs e)
{
OpenFileDialog dialog = new OpenFileDialog();
dialog.Multiselect = true;
if (dialog.ShowDialog() == DialogResult.OK)
{
String[] path = dialog.FileNames;
//String fileName = path.Substring(path.LastIndexOf("\\") + 1);
for (int i = 0; i < path.Count(); i++)
FlatfileTextBox.Text += path[i] + "@";
}
}
private void UploadAdjustmentReportButton_Click(object sender, EventArgs e)
{
OpenFileDialog dialog = new OpenFileDialog();
dialog.Multiselect = false;
if (dialog.ShowDialog() == DialogResult.OK)
{
String path = dialog.FileName;
AdjustmentReportTextBox.Text = path;
}
}
private void CompareButton_Click(object sender, EventArgs e)
{
OleDbConnection objConn, objConn1, objConn2;
DataTable dt, dt1, dt2, TableA, TableB, TableC;
string sql, sql1, sql2;
OleDbDataAdapter oleDA;
DataSet ds;
string transactionReport = TransactionFileNameTextBox.Text;
string movementReport = MovementReportTextBox.Text;
string adjustmentReport = AdjustmentReportTextBox.Text;
String sConnectionString1 = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" +
transactionReport + ";" + "Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";
String sConnectionString2 = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source="
+ movementReport + ";" + "Extended Properties =\"Excel 12.0;HDR=YES;IMEX=1\"";
String sConnectionString3 = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source="
+ adjustmentReport + ";" + "Extended Properties =\"Excel 12.0;HDR=YES;IMEX=1\"";
//TRANSACTION FILE
objConn = new OleDbConnection(sConnectionString1);
objConn.Open();
dt = objConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
sql = "SELECT * from [Sheet$]";
oleDA = new OleDbDataAdapter(sql, sConnectionString1);
ds = new DataSet();
oleDA.Fill(ds);
TableA = ds.Tables[0];
objConn.Close();
//dataGridView.DataSource = _DtTable;
//MOVEMENT FILE
objConn1 = new OleDbConnection(sConnectionString2);
objConn1.Open();
dt1 = objConn1.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
sql1 = "SELECT * from [Sheet$]";
oleDA = new OleDbDataAdapter(sql1, sConnectionString2);
ds = new DataSet();
oleDA.Fill(ds);
TableB = ds.Tables[0];
objConn1.Close();
//dataGridView.DataSource = _DtTable1;
//ADJUSTMENT FILE
objConn2 = new OleDbConnection(sConnectionString3);
objConn2.Open();
dt2 = objConn2.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
sql2 = "SELECT * from [Sheet$]";
oleDA = new OleDbDataAdapter(sql2, sConnectionString3);
ds = new DataSet();
oleDA.Fill(ds);
TableC = ds.Tables[0];
objConn2.Close();
//dataGridView1.DataSource = TableC;
//FLATFILES
//List<string> fileLines = System.IO.File.ReadAllLines(FlatfileTextBox.Text).ToList();
DataTable TableD = ConvertToDataTable(FlatfileTextBox.Text, 4);
//dataGridView1.DataSource = tableD;
DataTable FlatFileTable = new DataTable();
FlatFileTable.Columns.Add(new DataColumn("Location"));
FlatFileTable.Columns.Add(new DataColumn("Item Type"));
FlatFileTable.Columns.Add(new DataColumn("Type"));
FlatFileTable.Columns.Add(new DataColumn("PO Total Cost(Qty Received)"));
FlatFileTable.Columns.Add(new DataColumn("Amount", typeof(double)));
FlatFileTable.Columns.Add(new DataColumn("Amount Difference"));
foreach (DataRow rowA in TableA.Rows)
{
foreach (DataRow rowD in TableD.Rows)
{
if (Convert.ToDouble(rowD["Amount"]) > 0)
{
if (rowA["Location"].ToString().Substring(0, 5).Trim() == rowD["Location"].ToString() && rowD["Type"].ToString() == "GRN" && rowA["Item Type"].ToString() == rowD["Item Type"].ToString())
{
var newRow = FlatFileTable.NewRow();
newRow["Location"] = rowD["Location"];
newRow["Item Type"] = rowD["Item Type"];
newRow["Type"] = rowD["Type"];
newRow["PO Total Cost(Qty Received)"] = rowA["PO Total Cost(Qty Received)"];
//sum += Convert.ToDouble(rowD["Amount"]);
newRow["Amount"] = rowD["Amount"];
var newSort = from row in FlatFileTable.AsEnumerable()
group row by new { Location = row.Field<string>("Location"), Item_Type = row.Field<string>("Item Type"), Type = row.Field<string>("Type") } into grp
select new
{
Location = grp.Key.Location,
//Item_Type = grp.Key.Item_Type,
Type = grp.Key.Type,
Amount = grp.Sum(r => r.Field<double>("Amount"))
};
//dataGridView1.DataSource = table;
//newRow["Amount Difference"] = Convert.ToDouble(rowA["PO Total Cost(Qty Received)"]) - Convert.ToDouble(rowD["Amount"]);
FlatFileTable.Rows.Add(newRow);
//FlatFileTable.Rows.Add(newSort.ToList());
//dataGridView1.DataSource = FlatFileTable;
//DataTable TableZ = newSort.Copt
dataGridView.DataSource = Comparison(TableA, TableB, FlatFileTable);
}
}
}
}
//dataGridView1.DataSource = FlatFileTable;
//dataGridView.DataSource = Comparison(TableA, TableB, newSort.);
//I want to pass into this function so I can compare between them
}
public DataTable ConvertToDataTable(string filePath, int numberOfColumns)
{
DataTable tbl = new DataTable();
tbl.Columns.Add(new DataColumn("Type"));
tbl.Columns.Add(new DataColumn("Amount", typeof(double)));
tbl.Columns.Add(new DataColumn("Location"));
tbl.Columns.Add(new DataColumn("Item Type"));
//foreach(var file in filePath)
string[] MultipleFiles = filePath.Split('@');
for (int i = 0; i < MultipleFiles.Count() - 1; i++)
{
string[] lines = System.IO.File.ReadAllLines(MultipleFiles[i]);
foreach (string line in lines)
{
var cols = line.Split('|');
var count = 0;
DataRow dr = tbl.NewRow();
for (int cIndex = 7; cIndex < 11; cIndex++)
{
dr[count] = cols[cIndex];
count++;
}
tbl.Rows.Add(dr);
}
}
return tbl;
}
public DataTable Comparison(DataTable A, DataTable B, DataTable C)
{
var tableC = new DataTable();
tableC.Columns.Add(new DataColumn("Location"));
tableC.Columns.Add(new DataColumn("Item Type"));
tableC.Columns.Add(new DataColumn("PO Total Cost(Qty Received)"));
tableC.Columns.Add(new DataColumn("Qty Received Actual Cost"));
tableC.Columns.Add(new DataColumn("Amount from FlatFile"));
tableC.Columns.Add(new DataColumn("Amount (Transaction - Movement)"));
tableC.Columns.Add(new DataColumn("Amount (Transaction - FlatFile)"));
foreach (DataRow rowA in A.Rows)
{
foreach (DataRow rowB in B.Rows)
{
foreach (DataRow rowC in C.Rows)
{
if (rowA["Location"].ToString() == rowB["Location"].ToString() && rowA["Item Type"].ToString() == rowB["Item Type"].ToString() &&
rowA["Location"].ToString().Substring(0, 5).Trim() == rowC["Location"].ToString() && rowA["Item Type"].ToString() == rowC["Item Type"].ToString())
{
var newRow = tableC.NewRow();
newRow["Location"] = rowA["Location"];
newRow["Item Type"] = rowA["Item Type"];
newRow["PO Total Cost(Qty Received)"] = rowA["PO Total Cost(Qty Received)"];
newRow["Qty Received Actual Cost"] = rowB["Qty Received Actual Cost"];
newRow["Amount from FlatFile"] = rowC["Amount"];
newRow["Amount (Transaction - Movement)"] = Convert.ToDouble(rowA["PO Total Cost(Qty Received)"]) - Convert.ToDouble(rowB["Qty Received Actual Cost"]);
newRow["Amount (Transaction - FlatFile)"] = Convert.ToDouble(rowA["PO Total Cost(Qty Received)"]) - Convert.ToDouble(rowC["Amount"]);
tableC.Rows.Add(newRow);
}
//}
}
}
}
return tableC;
}
private void ComparisonForm_Load(object sender, EventArgs e)
{
}
}
}
答案 0 :(得分：2)
但是它的顺序错误，其中不包含任何元素。
您收到上述错误，因为集合中显然没有记录，并且在这种情况下First失败。您需要FirstOrDefault，如果集合中没有任何项目，它将返回null：
var firstRecord = records.FirstOrDefault();