Question

我需要能够将数据从dataGridView保存到.txt，然后才能将相同的数据加载到适当的位置。它是数据绑定。

这是我到目前为止的代码。我可以保存到文件但是，它只会将文件中的第一条记录加载到dataGridView中。非常感谢任何帮助！

private void LoadButton_Click(object sender, EventArgs e)
    {
        if (openFileDialog1.ShowDialog().Equals(DialogResult.OK))
        {
            cardlist = new List<Card>();
            using (System.IO.StreamReader file = new System.IO.StreamReader(openFileDialog1.FileName))
            {
                Card newcard = new Card();
                newcard.CardName = file.ReadLine();
                newcard.NumBorrowed = Convert.ToInt32(file.ReadLine());
                cardlist.Add(newcard);
            }
            dataGridView1.DataSource = cardlist;

        }
    }

    private void SaveButton_Click(object sender, EventArgs e)
    {
        if (saveFileDialog1.ShowDialog().Equals(DialogResult.OK))
        {
            using (System.IO.StreamWriter file = new System.IO.StreamWriter(saveFileDialog1.FileName))
                foreach (Card currentCard in cardlist)
                {
                    file.WriteLine(currentCard.CardName);
                    file.WriteLine(currentCard.NumBorrowed);
                }
        }
    }
    public class Card
    {
        public String CardName { get; set; }
        public int NumBorrowed { get; set; }
    }

Answer 1

您需要遍历文件中的所有项目

替换它：

using (System.IO.StreamReader file = new System.IO.StreamReader(openFileDialog1.FileName))
{
    Card newcard = new Card();
    newcard.CardName = file.ReadLine();
    newcard.NumBorrowed = Convert.ToInt32(file.ReadLine());
    cardlist.Add(newcard);
}

有了这个：

int lineCount=0;
string line=string.Empty;
using (System.IO.StreamReader file = new System.IO.StreamReader(openFileDialog1.FileName))
{
    Card newcard = new Card();
    while((line=file.ReadLine()) != null)
    {
    if(lineCount == 0)
    {
     newcard.CardName = line;
     lineCount = 1;
    }
    else if(lineCount == 1)
    {
     newcard.NumBorrowed = Convert.ToInt32(line);
     lineCount = 0;
    }
     cardlist.Add(newcard);
}

或

int i=0; foreach(var line in File.ReadLines(openFileDialog1.FileName)) { Card newcard = new Card(); if(i==0) { newcard.CardName = line; i = 1; } else if(i==1) { newcard.NumBorrowed = Convert.ToInt32(line); i=0; } cardlist.Add(newcard); }

Answer 2

请尝试以下代码：

using (System.IO.StreamReader file = new System.IO.StreamReader(openFileDialog1.FileName))
{
    string line;

    while ((line = file.ReadLine()) != null)
    {
        Card newcard = new Card();
        newcard.CardName = line;
        newcard.NumBorrowed = Convert.ToInt32(line);
        cardlist.Add(newcard);
    }
}

这将导致代码循环遍历文件，直到它到达空行（即文件结尾）。

这会将整个行放在CardName和NumBorrowed内。

为了使其正常工作，您需要为每个循环读取2行，如下所示：

string line;
string line2;

while ((line = file.ReadLine()) != null && (line2 = file.ReadLine()) != null) {
}

然后你可以更正你的代码：

Card newcard = new Card();
newcard.CardName = line;
newcard.NumBorrowed = Convert.ToInt32(line2);
cardlist.Add(newcard);

或者，您可以更改文件格式，而不是每个信息有2行，您可以将其压缩到一行具有单独的值（即Jake^50其中^是分隔符）

然后，您需要修改代码以将行拆分为数组并从中拉取值。

Answer 3

如果我有我的druthers，我写的文本文件用每行一条记录分隔，然后不用担心1条坏线会弄乱所有以下的行，但是对于你当前的结构，这应该有用了有一点错误检查。

        using (StreamReader reader = new StreamReader(openFileDialog1.FileName))
        {
            bool stillReading = true;
            while (stillReading)
            {
                string card, numBorrowed;
                card = reader.ReadLine();
                numBorrowed = reader.ReadLine();
                if (card != null && numBorrowed != null)
                {
                    int numB;
                    Card newcard = new Card
                    {
                        CardName = card,
                        NumBorrowed = Int32.TryParse(numBorrowed, out numB) ? numB : 0
                    };
                    cardlist.Add(newcard);
                }
                else
                {
                    stillReading = false;
                }
            } 
        }

保存到文本文件和dataGridView C＃并加载

3 个答案: