从文本文件中读取固定宽度的记录 [英] Read fixed width record from text file

问题描述

我有一个充满记录的文本文件，其中每条记录中的每个字段的宽度都是固定的.我的第一种方法是简单地使用 string.Substring() 解析每条记录.有没有更好的办法?

I've got a text file full of records where each field in each record is a fixed width. My first approach would be to parse each record simply using string.Substring(). Is there a better way?

例如，格式可以描述为:

For example, the format could be described as:

<Field1(8)><Field2(16)><Field3(12)>

具有两条记录的示例文件可能如下所示:

And an example file with two records could look like:

SomeData0000000000123456SomeMoreData
Data2   0000000000555555MoreData    

我只是想确保我没有忽略比 Substring() 更优雅的方式.

I just want to make sure I'm not overlooking a more elegant way than Substring().

更新:我最终使用了 Killersponge 建议的正则表达式:

Update: I ultimately went with a regex like Killersponge suggested:

private readonly Regex reLot = new Regex(REGEX_LOT, RegexOptions.Compiled);
const string REGEX_LOT = "^(?<Field1>.{6})" +
                        "(?<Field2>.{16})" +
                        "(?<Field3>.{12})";

然后我使用以下内容访问字段:

I then use the following to access the fields:

Match match = reLot.Match(record);
string field1 = match.Groups["Field1"].Value;

推荐答案

Substring 对我来说听起来不错.我能立即想到的唯一缺点是这意味着每次都复制数据，但在您证明这是一个瓶颈之前，我不会担心这一点.子串很简单:)

Substring sounds good to me. The only downside I can immediately think of is that it means copying the data each time, but I wouldn't worry about that until you prove it's a bottleneck. Substring is simple :)

您可以使用正则表达式一次匹配整个记录并捕获字段，但我认为这有点矫枉过正.

You could use a regex to match a whole record at a time and capture the fields, but I think that would be overkill.

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