只讀指定範圍

Question

我有一個文本文件，我只想從中讀取指定的跨度（如位置20到80）。

我正在使用下面的代碼，但它從0讀取跨度的長度。

char[] buffer = new char[span.Length]; 
using (StreamReader reader = new StreamReader(filename)) 
{    
    reader.ReadBlock(buffer, 0, span.Length); 
} 

有人可以幫我嗎？由於

Answer 1

char[] buffer = new char[span.Length]; 
using (StreamReader reader = new StreamReader(filename)) 
{  
    reader.BaseStream.Seek(span.Start, SeekOrigin.Begin); // or SeekOrigin.Current if you want to loop 
    reader.Read(buffer, 0, span.Length); 
} 

假設的span類型有Start屬性。

Answer 2

你試過了嗎？

char[] buffer = new char[span.Length]; 
using (StreamReader reader = new StreamReader(filename)) 
{    
    reader.ReadBlock(buffer, 20, span.Length); 
} 

Answer 3

char[] buffer = new char[span.Length]; 
using (StreamReader reader = new StreamReader(filename)) 
{    
    reader.ReadBlock(buffer, startIndex, span.Length); 
} 

的startIndex =從哪裏開始
span.Length =字符的數量閱讀