ComBoBox control, if there is an empty item in it, then report the solution of ntdll.dll
ComBoBox control, if there is item is empty, then report ntdll.dll solution
After searching online, I finally found a solution and downloaded a pas file
After adding this pas file to project, there is no error reported. It is really good.
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Copy the following code and save it to D7ComboBoxStringsGetPatch.pas
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unit D7ComboBoxStringsGetPatch;
// The patch fixes TCustomComboBoxStrings.Get method for empty string item in Delphi 7.
interface
{$IF RTLVersion 15.0}
'This patch is intended for Delphi 7 only';
{$IFEND}
implementation
uses
Windows, SysUtils, StdCtrls;
resourcestring
RsPatchingFailed = 'TCustomComboBoxStrings.Get patching failed. ';
type
TPatchResult = (prNotNeeded, prOk, prError);
function PatchCode(RoutineStartAddr: Pointer; PatchOffset: Cardinal; OriginalCode: Pointer;
OriginalCodeLen: Cardinal; PatchedCode: Pointer; PatchedCodeLen: Cardinal): TPatchResult;
const
JmpOpCode = $25FF;
type
PPackageThunk = ^TPackageThunk;
TPackageThunk = packed record
JmpInstruction: Word;
JmpAddress: PPointer;
end;
var
CodeStart: Pointer;
BytesWritten: DWORD;
begin
if FindClassHInstance(System.TObject) HInstance then
with PPackageThunk(RoutineStartAddr)^ do
if JmpInstruction = JmpOpCode then
RoutineStartAddr := JmpAddress^
else
begin
Result := prError;
Exit;
end;
CodeStart := Pointer(LongWord(RoutineStartAddr) + PatchOffset);
if CompareMem(CodeStart, OriginalCode, OriginalCodeLen) then
begin
if WriteProcessMemory(GetCurrentProcess, CodeStart, PatchedCode, PatchedCodeLen, BytesWritten) and
(BytesWritten = PatchedCodeLen) then
begin
FlushInstructionCache(GetCurrentProcess, CodeStart, PatchedCodeLen);
Result := prOk;
end
else
Result := prError;
end
else
Result := prNotNeeded;
end;
type
TCustomComboBoxStringsHack = class(TCustomComboBoxStrings);
function AddrOfTCustomComboBoxStringsGet: Pointer;
begin
Result := @TCustomComboBoxStringsHack.Get;
end;
procedure PatchTCustomComboBoxStringsGet;
const
OriginalCode: Cardinal = $74FFF883; // CMP EAX, -1 | JZ +$26
PatchedCode: Cardinal = $7E00F883; // CMP EAX, 0 | JLE +$26
PatchOffset = $1F;
// for DEBUG DCU by Pavel Rogulin
OriginalCodeD: Cardinal = $FFF07D83;
PatchedCodeD: Cardinal = $00F07D83;
PatchOffsetD = $2E;
var
PatchResult: TPatchResult;
begin
PatchResult := PatchCode(AddrOfTCustomComboBoxStringsGet, PatchOffset, @OriginalCode, SizeOf(OriginalCode),
@PatchedCode, SizeOf(PatchedCode));
if PatchResult = prNotNeeded then
PatchResult := PatchCode(AddrOfTCustomComboBoxStringsGet, PatchOffsetD, @OriginalCodeD, SizeOf(OriginalCodeD),
@PatchedCodeD, SizeOf(PatchedCodeD));
case PatchResult of
prError:
begin
if IsConsole then
WriteLn(ErrOutput, RsPatchingFailed)
else
MessageBox(0, PChar(RsPatchingFailed), nil, MB_OK or MB_ICONSTOP or MB_TASKMODAL);
RunError(1);
end;
end;
end;
initialization
PatchTCustomComboBoxStringsGet;
end.
Address of this article: http://www.xszlo.com/article/2012-11-10/7497.html, please keep this address for forwarding, thank you
