dll通用操作单元

dll通用操作单元

1/// <author>cxg 2019-3-4</author>
2/// 装载（释放）DLL
3/// 适用于Delphi所有版本
4
5unit ynDLL;
6
7interface
8
9uses
10  Classes, Windows, SysUtils;
11
12type
13  TDll = record
14    dllName: string;
15    dllHandle: Cardinal;
16  end;
17
18var
19  dllList: array of TDll;
20
21type
22  TynFun = function(params: string): string; stdcall;
23/// <summary>
24/// 执行指名DLL里面的指名函数
25/// </summary>
26/// <param name="dllName">DLL文件名</param>
27/// <param name="procName">函数名</param>
28/// <param name="inParams">函数入参</param>
29/// <returns>结果</returns>
30
31function ExecDllProc(const dllName, procName, inParams: string): string;
32/// <summary>
33/// 释放所有加载的DLL
34/// </summary>
35
36procedure FreeDllList;
37/// <summary>
38/// 获取指定文件夹里面的所有文件名，不包括其子文件夹
39/// </summary>
40/// <param name="path">文件夹</param>
41/// <param name="ext">文件扩展名，默认是所有类型</param>
42/// <returns></returns>
43
44function SearchFiles(path: string; ext: string = '*.*'): TStringList;
45/// <summary>
46/// 加载指名文件夹里面的所有DLL
47/// </summary>
48/// <param name="path">文件夹</param>
49
50procedure LoadAllDll(path: string);
51
52implementation
53
54function SearchFiles(path: string; ext: string = '*.*'): TStringList;
55var
56  SearchRec: TSearchRec;
57  found: integer;
58begin
59  Result := TStringList.Create;
60  found := FindFirst(path + '\' + ext, faAnyFile, SearchRec);
61  while found = 0 do
62  begin
63    if (SearchRec.Name <> '.') and (SearchRec.Name <> '..') and (SearchRec.Attr <> faDirectory) then
64      Result.Add(SearchRec.Name);
65    found := FindNext(SearchRec);
66  end;
67  FindClose(SearchRec);
68end;
69
70procedure FreeDllList;
71var
72  i: integer;
73begin
74  for i := Low(dllList) to High(dllList) do
75  begin
76    FreeLibrary(dllList[i].dllHandle);
77  end;
78end;
79
80procedure LoadAllDll(path: string);
81var
82  list: TStringList;
83  fullName: string;
84  i: integer;
85  handle: Cardinal;
86  dll: TDll;
87begin
88  list := SearchFiles(path, '*.dll');
89  SetLength(dllList, list.Count);
90  for i := 0 to list.Count - 1 do
91  begin
92    fullName := path + '\' + list[i];
93    handle := LoadLibrary(PChar(fullName));
94    if handle <> 0 then
95    begin
96      dll.dllName := list[i];
97      dll.dllHandle := handle;
98      dllList[i] := dll;
99    end;    
100  end;  
101  if Assigned(list) then
102    list.Free;
103end;
104
105function ExecDllProc(const dllName, procName, inParams: string): string;
106var
107  LHandle: Cardinal;
108  LPointer: Pointer;
109  LDll: TDll;
110  LSize: Integer;
111
112  function ExistDll(const dll: string): Cardinal;
113  var
114    i: Integer;
115    s: string;
116  begin
117    result := 0;
118    s := ExtractFileName(dll);
119    for i := 0 to High(dllList) do
120    begin
121      if SameText(s, dllList[i].dllName) then
122      begin
123        result := dllList[i].dllHandle;
124        Exit;
125      end;
126    end;
127  end;
128
129begin
130  Result := '';
131  if (dllName = '') or (procName = '') then
132    Exit;
133  LHandle := ExistDll(dllName);
134  if LHandle = 0 then
135  begin
136    if LHandle = 0 then                         // dll not loaded
137    try
138      LHandle := LoadLibrary(PChar(dllName));     // load dll
139      LDll.dllName := ExtractFileName(dllName);
140      LDll.dllHandle := LHandle;
141      LSize := High(dllList);
142      if LSize = -1 then             // dllList not init
143      begin
144        SetLength(dllList, 1);
145        dllList[0] := LDll;
146      end
147      else
148      begin
149        SetLength(dllList, LSize + 2);
150        dllList[LSize] := LDll;
151      end;
152      LPointer := GetProcAddress(LHandle, PChar(procName)); // load function
153      if LPointer <> nil then
154      begin
155        Result := TynFun(LPointer)(inParams)            // execute function and get result
156      end;
157    except
158      FreeLibrary(LHandle);
159    end;
160  end
161  else
162  begin                                                   // dll is loaded
163    LPointer := GetProcAddress(LHandle, PChar(procName)); // load function
164    if LPointer <> nil then
165    begin
166      Result := TynFun(LPointer)(inParams)                // execute function and get result
167    end;
168  end;
169end;
170
171end.