c#-4.0 - 如何修复 System.FormatException 从文本文件读取数据到列表框

问题描述

我的代码从表单应用程序中获取数据并将结果显示在列表框中并将数据保存在文件中。接下来我加载代码时，它应该从文件中读取数据并填充列表框。我有一个 System.FormatException 输入字符串格式不正确。

在我准备好读取文件之前，代码一直有效。我已经删除了空格和美元符号，但问题仍然存在。请任何帮助将不胜感激。

我的 FileIO 类代码如下

public static class FileIO
{
    const string path = "Customers.txt";

    // writes data from the array to the file
    public static void WriteData(List<Customer> customers)
    {
        FileStream fs = null;
        StreamWriter sw = null;
        try
        {
            // open the file for writing; overwrite old content

            fs = new FileStream(path, FileMode.Create, FileAccess.Write);
            sw = new StreamWriter(fs);
            // write data
            foreach (Customer item in customers)
                sw.WriteLine(item.DisplayCustomersInfo("|"));
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error while writing to the file: " +
                ex.Message, ex.GetType().ToString());
        }
        finally
        {
            if (sw != null) sw.Close(); // also closes fs
        }
    }

    // reads data from the file, puts in a list, and returns it
    public static List<Customer> ReadData()
    {
        List<Customer> customers = new List<Customer>();

        FileStream fs = null;
        StreamReader sr = null;
        string line; // for reading
        string[] columns; // result from splitting the line
                          // open the file for reading and read number into data
        try
        {
            fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read);
            sr = new StreamReader(fs);
            while (!sr.EndOfStream) // while there is data in the file
            {
                line = sr.ReadLine(); // read the next line
                line.Trim();
                columns = line.Split(','); // split line into substring from line with comma delimiters

                Customer c = new Customer(Convert.ToInt32(columns[0]), columns[1], Convert.ToChar(columns[2]),
                Convert.ToDecimal(columns[3].Remove(0, 1)));//this is where I think the problem is.

                               customers.Add(c);

            }
        }
        catch (FormatException)
        {
            MessageBox.Show("File contains bad format data. Aborting reading");
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error while reading the file: "
                + ex.Message, ex.GetType().ToString());
        }
        finally
        {
            // close the file if open
            if (sr != null) sr.Close(); //file stream gets closed too
        }
        return customers;
    }
}

下面是文本文件。

12345|RRRR|R|$58.05

12345|CCCCC|C|$60.05

12345|IIII|I|$116.09

我用过 , 和 ; 作为使用 | 之前的分隔符。

我希望从文件中读取数据并填充列表框并添加更多数据。

标签： c#-4.0

c#-4.0 - 如何修复 System.FormatException 从文本文件读取数据到列表框

问题描述

解决方案

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