Delphi

Question:
For evaluation, I would like to have application that shows the list of installed software in my computer. Can you give me?

Answer:
Yup, since those data keep inside registry, we cant avoid to use registry unit.
Here the codes:

uses
Registry;


procedure TForm1.Button1Click(Sender: TObject);
const
UNINST_PATH = 'SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall';
var
Reg: TRegistry;
SubKeys: TStringList;
ListItem: TlistItem;
i: integer;
sDisplayName, sUninstallString: string;
begin
{
ListView1.ViewStyle := vsReport;
ListView1.Columns.add;
ListView1.Columns.add;
ListView1.Columns[0].caption := 'DisplayName';
ListView1.Columns[1].caption := 'UninstallString';
ListView1.Columns[0].Width := 300;
ListView1.Columns[1].Width := 300;
}
Reg := TRegistry.Create;
with Reg do
try
with ListView1.Items do
try
BeginUpdate;
Clear;
RootKey := HKEY_LOCAL_MACHINE;
if OpenKeyReadOnly(UNINST_PATH) then
begin
SubKeys := TStringList.Create;
try
GetKeyNames(SubKeys);
CloseKey;
for i := 0 to subKeys.Count - 1 do
if OpenKeyReadOnly(Format('%s\%s', [UNINST_PATH, SubKeys[i]])) then
try
sDisplayName := ReadString('DisplayName');
sUninstallString := ReadString('UninstallString');
if sDisplayName <> '' then
begin
ListItem := Add;
ListItem.Caption := sDisplayName;
ListItem.subitems.Add(sUninstallString);
end;
finally
CloseKey;
end;
finally
SubKeys.Free;
end;
end;
finally
ListView1.AlphaSort;
EndUpdate;
end;
finally
CloseKey;
Free;
end;
end;

Question:
I want to get Windows System Directory, can you show me?

Answer:
Sure, please check this example below. Not only to get Windows System Directory but also Temporary Directory and Windows Directory.



{ Getting the Windows Directory }

function GetWinDir: string;
var
dir: array [0..MAX_PATH] of Char;
begin
GetWindowsDirectory(dir, MAX_PATH);
Result := StrPas(dir);
end;

function WindowsDirectory: string;
var
WinDir: PChar;
begin
WinDir := StrAlloc(MAX_PATH);
GetWindowsDirectory(WinDir, MAX_PATH);
Result := string(WinDir);
if Result[Length(Result)] <> '\' then
Result := Result + '\';
StrDispose(WinDir);
end;

function GetWindowsDirectory(var S: String): Boolean;
var
Len: Integer;
begin
Len := Windows.GetWindowsDirectory(nil, 0);
if Len > 0 then
begin
SetLength(S, Len);
Len := Windows.GetWindowsDirectory(PChar(S), Len);
SetLength(S, Len);
Result := Len > 0;
end else
Result := False;
end;
{ Getting the System Directory }

function SystemDir: string;
var
dir: array [0..MAX_PATH] of Char;
begin
GetSystemDirectory(dir, MAX_PATH);
Result := StrPas(dir);
end;

function SystemDirectory: string;
var
SysDir: PChar;
begin
SysDir := StrAlloc(MAX_PATH);
GetSystemDirectory(SysDir, MAX_PATH);
Result := string(SysDir);
if Result[Length(Result)] <> '\' then
Result := Result + '\';
StrDispose(SysDir);
end;

function GetSystemDirectory(var S: String): Boolean;
var
Len: Integer;
begin
Len := Windows.GetSystemDirectory(nil, 0);
if Len > 0 then
begin
SetLength(S, Len);
Len := Windows.GetSystemDirectory(PChar(S), Len);
SetLength(S, Len);
Result := Len > 0;
end else
Result := False;
end;
{ Getting the Temporary Directory }

function GetTempDir: string;
var
Buffer: array[0..MAX_PATH] of Char;
begin
GetTempPath(SizeOf(Buffer) - 1, Buffer);
Result := StrPas(Buffer);
end;

function GetTempPath: string;
var
TmpDir: PChar;
begin
TmpDir := StrAlloc(MAX_PATH);
GetTempPath(TmpDir, MAX_PATH);
Result := string(TmpDir);
if Result[Length(Result)] <> '\' then
Result := Result + '\';
StrDispose(TmpDir);
end;

function GetTempPath(var S: String): Boolean;
var
Len: Integer;
begin
Len := Windows.GetTempPath(0, nil);
if Len > 0 then
begin
SetLength(S, Len);
Len := Windows.GetTempPath(Len, PChar(S));
SetLength(S, Len);
Result := Len > 0;
end else
Result := False;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
label1.Caption := GetWinDir;
label2.Caption := GetSysDir;
label3.Caption := GetTempDir;
end;

Question:
I want to get position of exe path from window handle. Can I get the code?

Answer:
This not simple, but here the code:


uses
PsAPI, TlHelp32;
const
RsSystemIdleProcess = 'System Idle Process';
RsSystemProcess = 'System Process';

function IsWinXP: Boolean;
begin
Result := (Win32Platform = VER_PLATFORM_WIN32_NT) and
(Win32MajorVersion = 5) and (Win32MinorVersion = 1);
end;

function IsWin2k: Boolean;
begin
Result := (Win32MajorVersion >= 5) and
(Win32Platform = VER_PLATFORM_WIN32_NT);
end;

function IsWinNT4: Boolean;
begin
Result := Win32Platform = VER_PLATFORM_WIN32_NT;
Result := Result and (Win32MajorVersion = 4);
end;

function IsWin3X: Boolean;
begin
Result := Win32Platform = VER_PLATFORM_WIN32_NT;
Result := Result and (Win32MajorVersion = 3) and
((Win32MinorVersion = 1) or (Win32MinorVersion = 5) or
(Win32MinorVersion = 51));
end;

function RunningProcessesList(const List: TStrings; FullPath: Boolean): Boolean;

function ProcessFileName(PID: DWORD): string;
var
Handle: THandle;
begin
Result := '';
Handle := OpenProcess(PROCESS_QUERY_INFORMATION or PROCESS_VM_READ, False, PID);
if Handle <> 0 then
try
SetLength(Result, MAX_PATH);
if FullPath then
begin
if GetModuleFileNameEx(Handle, 0, PChar(Result), MAX_PATH) > 0 then
SetLength(Result, StrLen(PChar(Result)))
else
Result := '';
end
else
begin
if GetModuleBaseNameA(Handle, 0, PChar(Result), MAX_PATH) > 0 then
SetLength(Result, StrLen(PChar(Result)))
else
Result := '';
end;
finally
CloseHandle(Handle);
end;
end;

function BuildListTH: Boolean;
var
SnapProcHandle: THandle;
ProcEntry: TProcessEntry32;
NextProc: Boolean;
FileName: string;
begin
SnapProcHandle := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
Result := (SnapProcHandle <> INVALID_HANDLE_VALUE);
if Result then
try
ProcEntry.dwSize := SizeOf(ProcEntry);
NextProc := Process32First(SnapProcHandle, ProcEntry);
while NextProc do
begin
if ProcEntry.th32ProcessID = 0 then
begin
FileName := RsSystemIdleProcess;
end
else
begin
if IsWin2k or IsWinXP then
begin
FileName := ProcessFileName(ProcEntry.th32ProcessID);
if FileName = '' then
FileName := ProcEntry.szExeFile;
end
else
begin
FileName := ProcEntry.szExeFile;
if not FullPath then
FileName := ExtractFileName(FileName);
end;
end;
List.AddObject(FileName, Pointer(ProcEntry.th32ProcessID));
NextProc := Process32Next(SnapProcHandle, ProcEntry);
end;
finally
CloseHandle(SnapProcHandle);
end;
end;

function BuildListPS: Boolean;
var
PIDs: array [0..1024] of DWORD;
Needed: DWORD;
I: Integer;
FileName: string;
begin
Result := EnumProcesses(@PIDs, SizeOf(PIDs), Needed);
if Result then
begin
for I := 0 to (Needed div SizeOf(DWORD)) - 1 do
begin
case PIDs[I] of
0:
FileName := RsSystemIdleProcess;
2:
if IsWinNT4 then
FileName := RsSystemProcess
else
FileName := ProcessFileName(PIDs[I]);
8:
if IsWin2k or IsWinXP then
FileName := RsSystemProcess
else
FileName := ProcessFileName(PIDs[I]);
else
FileName := ProcessFileName(PIDs[I]);
end;
if FileName <> '' then
List.AddObject(FileName, Pointer(PIDs[I]));
end;
end;
end;
begin
if IsWin3X or IsWinNT4 then
Result := BuildListPS
else
Result := BuildListTH;
end;

function GetProcessNameFromWnd(Wnd: HWND): string;
var
List: TStringList;
PID: DWORD;
I: Integer;
begin
Result := '';
if IsWindow(Wnd) then
begin
PID := INVALID_HANDLE_VALUE;
GetWindowThreadProcessId(Wnd, @PID);
List := TStringList.Create;
try
if RunningProcessesList(List, True) then
begin
I := List.IndexOfObject(Pointer(PID));
if I > -1 then
Result := List[I];
end;
finally
List.Free;
end;
end;
end;