File.ReadAllLines(FileName)数组大小限制 [英] File.ReadAllLines(FileName) array size limit

问题描述

如果我使用:

 字符串 FileName = " ;
字符串 [] DataFile = File.ReadAllLines(FileName); 

现在说文件有5行...
因此，DataFile数组的最后一个文件行位于4.

如果我想在DataFile [5]处添加一行(它位于数组的底部，并且超过文件位置的末尾)，则会得到一个OutOfRangeException，这是可以理解的.做我想做的最好的方法是什么?

解决方案

正如GanesanSenthilvel所说，使用List< string>而是使用Array.Resize()方法.

以下是一些示例:

列表< string> dataFile = 新列表< string>();
dataFile.AddRange(File.ReadAllLines(FileName)); 

那么您可以用相同的方式添加其他文件行

 dataFile.AddRange(File.ReadAllLines(SomeOtherFile)); 

或

 字符串 [] data = 新 "  等等"， 等等等等"， 等等等等"};
dataFile.AddRange(data); 

或一行

 dataFile.Add(" );  pre> 

或

 字符串 someData = " ;
dataFile.Add(someData); 
 



如果您确实想使用Array.Resize()方法，也可以使用

 字符串 [] data = 新  2 ];
data [ 0 ] = " ;
data [ 1 ] = " 跨度>;
Array.Resize( ref  data，data.Length +  1 );
data [ 2 ] = "  span>; 
 

您的目标是将行添加到现有文件的末尾
为什么不使用此代码

StreamWriter sw= File.AppendText("c:\\temp.txt");
            sw.WriteLine();
            sw.WriteLine("hello");
            sw.Flush();
            sw.Close();

谢谢
--RA

您可以很好地使用

 List< string> </ 字符串 >  

以避免OutOfRangeException

If I use:

string FileName = "MyFile.txt";
string[] DataFile = File.ReadAllLines(FileName);

Now say the file has 5 lines...
Therefore the DataFile array will have its last file line on 4.

If I want to add a line at say DataFile[5] (which is at the bottom of the array and past the end of file position), I get an OutOfRangeException which is understandable. What is the best way to do what I want to do? essentially I want the array to be resized.

解决方案

As GanesanSenthilvel said use a List<string> instead or the Array.Resize() method.

Here are some examples:

List<string> dataFile = new List<string>();
dataFile.AddRange(File.ReadAllLines(FileName));

then you could add another files lines in the same way

dataFile.AddRange(File.ReadAllLines(SomeOtherFile));

or

string[] data = new string[] { "blah", "blah blah", "blah blah blah" };
dataFile.AddRange(data);

or a single line

dataFile.Add("some line of data");

or

string someData = "blah blah blah blah";
dataFile.Add(someData);

You could if you really wanted to use the Array.Resize() method i.e.

string[] data = new string[2];
data[0] = "some data";
data[1] = "some more data";
Array.Resize(ref data, data.Length + 1);
data[2] = "even more data";

Your Target is add line to the existing file at end
why don''t you use this code

StreamWriter sw= File.AppendText("c:\\temp.txt");
            sw.WriteLine();
            sw.WriteLine("hello");
            sw.Flush();
            sw.Close();

Thanks
--RA

Instead of array of String, you can very well use

List<string></string>

to avoid OutOfRangeException

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