Java 與 C# 輸入輸出流操作對比詳解

Java 字節流讀取文件

try (FileInputStream fis = new FileInputStream("test.java")) {
    byte[] buf = new byte[1024];
    int len;
    while ((len = fis.read(buf)) > 0) {
        System.out.println(new String(buf, 0, len));
    }
}

Java 字符流讀取文件

try (FileReader fr = new FileReader("test.java")) {
    char[] buf = new char[32];
    int len;
    while ((len = fr.read(buf)) > 0) {
        System.out.println(new String(buf, 0, len));
    }
}

C# Stream 與 byte[] 互轉

// Stream → byte[]
public byte[] StreamToBytes(Stream stream) {
    byte[] bytes = new byte[stream.Length];
    stream.Read(bytes, 0, bytes.Length);
    stream.Seek(0, SeekOrigin.Begin); // 重置位置
    return bytes;
}

// byte[] → Stream
public Stream BytesToStream(byte[] bytes) {
    return new MemoryStream(bytes);
}

C# Stream 與文件互轉

// Stream → 文件
public void StreamToFile(Stream stream, string fileName) {
    byte[] bytes = StreamToBytes(stream);
    File.WriteAllBytes(fileName, bytes);
}

// 文件 → Stream
public Stream FileToStream(string fileName) {
    byte[] bytes = File.ReadAllBytes(fileName);
    return new MemoryStream(bytes);
}

核心差異對比

最佳實踐共性

• 優先使用緩衝流提升性能
• 指定字符集（UTF-8）避免亂碼
• 及時關閉流，釋放文件句柄
• 大文件分塊讀寫，避免 OOM