c# - 将 DataTable 分配给 DataGridView 时的 "NullReferenceException was unhandled"

Question

在包含 dgdMain.DataSource = dt; 的行上，我收到 “NullReferenceException was unhandled” 错误。我试图找到一个解决方案，我相信它很简单，但我显然错过了它。感谢您提供任何意见。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.OleDb;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Dashboard
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            BindingSource bindingSource = new BindingSource();
            DataTable dt = Program.GetDataTableFromCSV("../../res/sampledata.csv");
            dgdMain.DataSource = dt;

            InitializeComponent();

        }
    }
}

...这是 GetDataTableFromCSV() :

public static DataTable GetDataTableFromCSV(string path)
{
    DataTable dataTable = new DataTable();
    String[] values;

    values = File.ReadAllLines(path);

    string[] csvRows = System.IO.File.ReadAllLines(path);
    string[] headers = csvRows[0].Split(',');

    // Adding columns name
    foreach (var item in headers)
        dataTable.Columns.Add(new DataColumn(item));

    string[] fields = null;

    foreach (string csvRow in csvRows)
    {
        //Debug.Write(csvRow+"\r\n");
        fields = csvRow.Split(',');
        DataRow row = dataTable.NewRow();
        row.ItemArray = fields;
        dataTable.Rows.Add(row);
    }

    return dataTable;
}

Answer 1

InitializeComponent 必须在上面。应该是这样的:

    public frmMain()
    {
        InitializeComponent();

        BindingSource bindingSource = new BindingSource();
        DataTable dt = Program.GetDataTableFromCSV("../../res/sampledata.csv");
        dgdMain.DataSource = dt;
    }