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2026-06-10

获取OLA图像 - GetOlaImage ​

函数简介 ​

从OLA数据库中获取指定目录和文件名的图像数据，返回图像对象的指针。

接口名称 ​

GetOlaImage

DLL调用 ​

cpp
long GetOlaImage(long ola, const long db, string dir, string fileName);

参数说明 ​

参数名类型说明
ola长整型数OLAPlug对象的指针，由 CreateCOLAPlugInterFace 接口生成
db长整型数数据库连接句柄，由 OpenDatabase 接口生成
dir字符串图片目录路径
fileName字符串图片文件名

示例 ​

SDK 调用 ​

cpp
#include "OLAPlugServer.h"

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

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

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

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

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

原生 DLL 调用 ​

cpp
long instance = CreateCOLAPlugInterFace();
long ptr = GetOlaImage(instance, 0, "value", "C:\\test.txt");
if (ptr != 0) {
    char buffer[512] = {0};
    GetStringFromPtr(ptr, buffer, sizeof(buffer));
    FreeStringPtr(ptr);
}
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 int GetStringFromPtr(long ptr, StringBuilder lpString, int size);
[DllImport("OLAPlug_x64.dll", CallingConvention = CallingConvention.StdCall)]
static extern int FreeStringPtr(long ptr);
[DllImport("OLAPlug_x64.dll", CallingConvention = CallingConvention.StdCall)]
static extern int GetStringSize(long ptr);
[DllImport("OLAPlug_x64.dll", CallingConvention = CallingConvention.StdCall)]
static extern long GetOlaImage(long ola, long db, string dir, string fileName);

long instance = CreateCOLAPlugInterFace();
long ptr = GetOlaImage(instance, 0, "value", "C:\\test.txt");
if (ptr != 0) {
    StringBuilder sb = new StringBuilder(GetStringSize(ptr) + 1);
    GetStringFromPtr(ptr, sb, sb.Capacity);
    FreeStringPtr(ptr);
    string result = sb.ToString();
}
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()
ptr = ola.GetOlaImage(instance, 0, "value", "C:\\test.txt")
if ptr:
    buf = create_string_buffer(512)
    ola.GetStringFromPtr(ptr, buf, 512)
    ola.FreeStringPtr(ptr)
    result = buf.value.decode("utf-8")

返回值 ​

图像对象的指针。如果操作失败，返回 0。

注意事项 ​

  • 适用于从数据库中检索单个图像的场景。
  • 如果图像不存在或操作失败，可通过 GetDatabaseError 获取详细错误信息。
  • 使用完返回的图像对象指针后，应妥善处理资源，避免内存泄漏。