列表框不显示来自 C# 数据源的所需结果

Question

我下面的代码在运行时显示：

string filePath = @"C:\Users\Jim\Desktop\us-500.csv";
StreamReader sr = new StreamReader(filePath);
var lines = new List<string[]>();
int Row = 0;
while (!sr.EndOfStream)
{
    string[] Line = sr.ReadLine().Split(',');
    lines.Add(Line);
    Row++;
}

var data = lines.ToArray();

bindingSource1.DataSource = data;
listBox1.DataSource = bindingSource1;

如何让它向我显示如下所示的每一行字段？

Answer 1

在使用数据源时，数组不太好用。避免将列表转换为数组，因为这不是必需的。

bindingSource1.DataSource = lines;
bindingNavigator1.BindingSource = bindingSource1;

然后尝试使用 BindingSource 的 PositionChanged 事件为 ListBox 设置 DataSource：

void bindingSource1_PositionChanged(object sender, EventArgs e) {
  var items = bindingSource1.DataSource as List<string[]>;
  if (items != null && bindingSource1.Position >= 0 && 
                       bindingSource1.Position < items.Count ) {
    listBox1.DataSource = items[bindingSource1.Position];
  }
}

Answer 2

根据您的要求，我认为可以做到。

1. 阅读每一行
2. 将每一行分成多个字段
3. 将每个字段添加到数据源
4. 绑定到数据源

.

using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
using System.IO;

namespace PopulateListBoxFromCSV_46815162
{

    public partial class Form1 : Form
    {
        ListBox lstbx = new ListBox();
        public Form1()
        {
            InitializeComponent();
            initializeListBox();
            //fillTheListBox(@"C:\temp\myfile.csv");
            fillTheListBox(@"C:\temp\myfile.csv", true);
        }

        /// <summary>
        /// Lets say you want to show field value only
        /// </summary>
        /// <param name="filePath"></param>
        private void fillTheListBox(string filePath)
        {

            List<string> results = new List<string>();
            string currentLine = string.Empty;
            using (StreamReader sr = new StreamReader(filePath))
            {
                while ((currentLine = sr.ReadLine()) != null)//for as long as there is something to read
                {
                    foreach (string item in currentLine.Split(','))//split the current line into multiple "fields"
                    {
                        results.Add(item);//add each individual field to the dataSource to create your 1FieldPerLine visual
                    }
                }
            }
            lstbx.DataSource = results;//bind your datasource
        }


        /// <summary>
        /// Lets say you wanted to show "Header" : "FieldValue"
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="ShowHeader"></param>
        private void fillTheListBox(string filePath, bool ShowHeader)
        {
            List<string> headerLine = new List<string>();
            List<string> results = new List<string>();
            int whichLineAmIon = 0;
            string currentLine = string.Empty;
            using (StreamReader sr = new StreamReader(filePath))
            {
                while ((currentLine = sr.ReadLine()) != null)//for as long as there is something to read
                {
                    string[] splitted = currentLine.Split(',');//split the line into fields
                    for (int i = 0; i < splitted.Length; i++)
                    {
                        if (whichLineAmIon == 0)//then we are on the header line
                        {
                            headerLine.Add(splitted[i]);
                        }
                        else
                        {
                            results.Add(headerLine[i] + " : " + splitted[i]);//add each individual field to the dataSource to create your 1FieldPerLine visual
                        }
                    }
                    whichLineAmIon++;
                }
            }

            lstbx.DataSource = results;//bind your datasource
        }

        private void initializeListBox()
        {
            lstbx.Dock = DockStyle.Fill;
            lstbx.BackColor = Color.Azure;
            this.Controls.Add(lstbx);
        }
    }
}

Answer 3

这里 string[] Line = sr.ReadLine().Split(','); lines.Add(Line);

您添加的是字符串数组而不是字符串。

为了解决这个问题，你必须做其他的事情，像这样。

string[] Line = sr.ReadLine().Split(',');
for (int i = 0; i < Line.Length ; i++)
{
    lines.Add(Line[i]);
    Row++;
}

Answer 4

您的列表框仅显示对象。将其绑定到 DisplayMemberPath 属性。