Question

我在一个类中创建了一个DataTable对象并将其返回到主程序时遇到了一个问题。我调用一个method（1），该方法从数据表中检索一些信息，然后删除相同的行。然后，我运行另一个方法（2），该方法从列中检索数据，但是我可以看到在另一个方法（1）中删除的行没有生效。我已经计算了method（1）中的行数，并且行数确实减少了，这表明它们已被删除。

这与引用对象有关吗？

对于在问这个问题时遇到的任何错误，我们深表歉意。这是我对堆栈的第一个问题，我对编码还是很陌生。

谢谢！

主程序：

filepath = @"E:\1802370 11.05.18 qCML 6x10E6 ERM_analysed.txt";

//Create a datatable from _analysed file and delete unwated columns
DataTable dataTable = csv.convertToDataTable(filepath);

//Assign slope and r2 values for both BCR and ABL
//Delete rows after
plate.getSlopeandR2(dataTable);
plate.getSampleList(dataTable);

DataTable方法：

    //Converts text file into a datatable to be manipluated.
    public DataTable convertToDataTable(string filepath)
    {
        StreamReader sr = new StreamReader(filepath);

        string[] headers = sr.ReadLine().Split('\t');
        DataTable dt = new DataTable();
        foreach (string header in headers)
        {
            dt.Columns.Add(header);
        }
        while (!sr.EndOfStream)
        {
            string[] rows = Regex.Split(sr.ReadLine(), "\t");

            DataRow dr = dt.NewRow();
            for (int i = 0; i < headers.Length; i++)
            {
                dr[i] = rows[i];
            }
            dt.Rows.Add(dr);
        }

        sr.Close();
        return dt;

方法（1）：获取值删除行

    //Get slope and r2 values
    //Delete rows after info is retrieved
    public void getSlopeandR2(DataTable dataTable)
    {
        bool isABL = true;
        List<int> rowsToDelete = new List<int>();
        Console.WriteLine(dataTable.Rows.Count);

        foreach (DataRow row in dataTable.Rows)
        {
            int rowIndex;

            if (row["Well"].ToString() == "Slope" && isABL == true)
            {
                rowIndex = dataTable.Rows.IndexOf(row);
                ablSlope = Convert.ToDouble(dataTable.Rows[rowIndex][1]);
                ablR2 = Convert.ToDouble(dataTable.Rows[rowIndex + 2][2]);
                isABL = false;
                rowsToDelete.Add(rowIndex);
                rowsToDelete.Add(rowIndex + 1);
                rowsToDelete.Add(rowIndex + 2);
                rowsToDelete.Add(rowIndex + 3);
                rowsToDelete.Add(rowIndex + 4);
                rowsToDelete.Add(rowIndex + 5);

            }
            else if (row["Well"].ToString() == "Slope" && isABL == false)
            {
                rowIndex = dataTable.Rows.IndexOf(row);
                biomedSlope = Convert.ToDouble(dataTable.Rows[rowIndex][1]);
                biomedR2 = Convert.ToDouble(dataTable.Rows[rowIndex + 2][2]);
                rowsToDelete.Add(rowIndex);
                rowsToDelete.Add(rowIndex + 1);
                rowsToDelete.Add(rowIndex + 2);
                rowsToDelete.Add(rowIndex + 3);
                rowsToDelete.Add(rowIndex + 4);
                rowsToDelete.Add(rowIndex + 5);
                rowsToDelete.Add(rowIndex + 6);
            }

        }

        for (int i = 0; i < rowsToDelete.Count; i++)
        {
            dataTable.Rows.RemoveAt(i);
        }

        Console.WriteLine(dataTable.Rows.Count);
    }

方法（2）：检索数据（仍包括已删除的行）

        //Get unique list of sample ID's on plate
    public void getSampleList(DataTable dataTable)
    {
        string tempValue;

        foreach (DataRow row in dataTable.Rows)
        {
            if (!Samples.Contains(row["Sample Name"].ToString()))
            {
                tempValue = Convert.ToString(row["Sample Name"]);
                Samples.Add(tempValue);
            }
        }

        foreach (string id in Samples)
        {
            Console.WriteLine(id);
        }
    }

Answer 1

有两种方法可以从DataTable中删除DataRow。读取文件后，调用AcceptChanges（）在内部提交DataTable。

//Created new table sample
DataTable dt1 = new DataTable("dt1");
dt1.Columns.Add("Id", typeof(int));
dt1.Columns.Add("Name");

//Added dummy data
dt1.Rows.Add(1, "Abc");
dt1.Rows.Add(2, "Def");

//You must accept changes after reading file, so you can track changes
dt1.AcceptChanges();

//Below line will remove row permanently.
dt1.Rows.RemoveAt(0);

//Below line will mark row as deleted, still row count will be same till AcceptChanges() called.
dt1.Rows[0].Delete();
dt1.AcceptChanges();

Answer 2

从表中删除行后，接受更改

dataTable.AcceptChanges（）

for (int i = 0; i < rowsToDelete.Count; i++)
    {
        dataTable.Rows.RemoveAt(i);
        dataTable.AcceptChanges();
    }

C＃编辑DataTable更改未保存

2 个答案: