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2026-06-10

读取文件字节 - ReadBytesFromFile ​

函数简介 ​

从文件中读取指定偏移量和大小的字节数据。

接口名称 ​

ReadBytesFromFile

DLL调用 ​

c
long ReadBytesFromFile(long instance, string filePath, int offset, long size);

参数说明 ​

参数名类型说明
instance长整数型OLAPlug对象的指针，由 CreateCOLAPlugInterFace 接口生成。
filePath字符串要读取的文件完整路径。
offset整数型起始偏移量（字节）。
size长整数型读取的字节数，0 表示读取整个文件。

示例 ​

SDK 调用 ​

cpp
#include "OLAPlugServer.h"

OLAPlugServer ola;
long handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0);
csharp
using OLAPlug;

var ola = new OLAPlugServer();
long handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0);
python
from OLAPlugServer import OLAPlugServer

ola = OLAPlugServer()
handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0)
java
import com.olaplug.OLAPlugServer;

OLAPlugServer ola = new OLAPlugServer();
long handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0);
cpp
var ola = com("OlaPlug.OlaSoft")
var handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0)
vbscript
Set ola = CreateObject("OlaPlug.OlaSoft")
handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0)
text
.局部变量 ola, OLAPlug
ola.创建 ()
handle ＝ ola.ReadBytesFromFile("C:\\test.txt", 0, 0)
aardio
import OLAPlugServer;
var ola = OLAPlugServer();
var handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0);
text
变量 ola <类型 = OLAPlugServer>
ola = 新建 OLAPlugServer
长整数 handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0)
cpp
#include "OLAPlugServer.h"

OLAPlugServer ola;
long handle = ola.ReadBytesFromFile("C:\\test.txt", 0, 0);

原生 DLL 调用 ​

cpp
long instance = CreateCOLAPlugInterFace();
ReadBytesFromFile(instance, "C:\\test.txt", 0, 0);
csharp
using System.Runtime.InteropServices;
using System.Text;

[DllImport("OLAPlug_x64.dll", CallingConvention = CallingConvention.StdCall)]
static extern long CreateCOLAPlugInterFace();
[DllImport("OLAPlug_x64.dll", CallingConvention = CallingConvention.StdCall)]
static extern long ReadBytesFromFile(long ola, string filePath, int offset, long size);

long instance = CreateCOLAPlugInterFace();
ReadBytesFromFile(instance, "C:\\test.txt", 0, 0);
python
from ctypes import CDLL, c_int, c_int64, create_string_buffer

ola = CDLL("OLAPlug_x64.dll")
ola.CreateCOLAPlugInterFace.restype = c_int64
instance = ola.CreateCOLAPlugInterFace()
ola.ReadBytesFromFile(instance, "C:\\test.txt", 0, 0)

返回值 ​

返回字节缓冲区指针，失败返回0。

注意事项 ​

  • 返回的缓冲区指针需调用 [FreeMemoryPtr](/olaplug/其他/释放字节流内存 - FreeMemoryPtr.html) 接口释放内存。