怀念一下这些经常不记得的Delphi代码...
几年前混 大富翁论坛(delphibbs) 时，陆陆续续记录了很多不常用，但需要起来踏破Google、百度都找不到的技巧（Google这两年搜出来的垃圾网站越来越多...）。现在大富翁没落了，都给搬过来
1.防止刷新时闪烁的终极解决办法
{ 防止刷新时闪烁的终极解决办法(对付双缓冲无效时) }
Perform($000B, 0, 0); //锁屏幕 防止闪烁
// 做一些会发生严重闪烁的事情..
//解锁屏幕并重画
Perform($000B, 1, 0);
RedrawWindow(Handle, nil, 0, RDW_FRAME + RDW_INVALIDATE + RDW_ALLCHILDREN + RDW_NOINTERNALPAINT);
Perform($000B, 0, 0); //锁屏幕 防止闪烁
// 做一些会发生严重闪烁的事情..
//解锁屏幕并重画
Perform($000B, 1, 0);
RedrawWindow(Handle, nil, 0, RDW_FRAME + RDW_INVALIDATE + RDW_ALLCHILDREN + RDW_NOINTERNALPAINT);
2.图片上显示透明文字
//图片上显示透明的文字
//直接用.Canvas.Brush.Style:=bsClear;
//然后.Canvas.TextOut(x,y,'文字显示透明');
procedure TForm1.Button1Click(Sender: TObject);
var
bitBuf:TBitmap;
begin
bitBuf := TBitmap.Create;
try
bitbuf.LoadFromFile('测试图片.bmp');
Self.Canvas.Draw(0,0,bitbuf);
bitbuf.Transparent := True;
bitbuf.TransparentColor := clWhite; //文字显示透明
bitbuf.Canvas.font.color := clBlue; //文字颜色
bitbuf.Canvas.TextOut(10,10,'这样就是透明的字了！');
Self.Canvas.Draw(0,0,bitbuf);
finally
bitBuf.Free;
end;
end;
//直接用.Canvas.Brush.Style:=bsClear;
//然后.Canvas.TextOut(x,y,'文字显示透明');
procedure TForm1.Button1Click(Sender: TObject);
var
bitBuf:TBitmap;
begin
bitBuf := TBitmap.Create;
try
bitbuf.LoadFromFile('测试图片.bmp');
Self.Canvas.Draw(0,0,bitbuf);
bitbuf.Transparent := True;
bitbuf.TransparentColor := clWhite; //文字显示透明
bitbuf.Canvas.font.color := clBlue; //文字颜色
bitbuf.Canvas.TextOut(10,10,'这样就是透明的字了！');
Self.Canvas.Draw(0,0,bitbuf);
finally
bitBuf.Free;
end;
end;
3.取得本机IP地址(精简版)
//取得本地IP地址(精简版)
//注：使用函数前需要 WSAStartup($202, wsdata);
function GetLocalIP(): String;
var
HostName: array[0..255] of Char;
HostEnt: PHostEnt;
begin
Result := '';
if gethostname(HostName, 255) = 0 then
begin
HostEnt := gethostbyname(HostName);
Result := StrPas(inet_ntoa(PInAddr(PInAddr(HostEnt^.h_addr_list)^)^));
end;
end;
//注：使用函数前需要 WSAStartup($202, wsdata);
function GetLocalIP(): String;
var
HostName: array[0..255] of Char;
HostEnt: PHostEnt;
begin
Result := '';
if gethostname(HostName, 255) = 0 then
begin
HostEnt := gethostbyname(HostName);
Result := StrPas(inet_ntoa(PInAddr(PInAddr(HostEnt^.h_addr_list)^)^));
end;
end;
4.报告内存泄漏
// 在程序中加上这句，当退出时会报告内存泄漏
ReportMemoryLeaksOnShutdown := True;
ReportMemoryLeaksOnShutdown := True;
5.释放资源文件
// 首先加入.RC文件，写上 MyDLL DAT testDLL.dll
// 然后程序里 ExtractRes('DAT','MyDLL','123DLL.dll');
procedure ExtractRes(ResType, ResName, ResNewName:String);
var Res:TResourceStream;
begin
Res:=TResourceStream.Create(Hinstance, Resname, Pchar(ResType));
try
Res.SavetoFile('.\'+ResNewName); // 释放到当前目录
finally
Res.Free;
end;
end;
// 然后程序里 ExtractRes('DAT','MyDLL','123DLL.dll');
procedure ExtractRes(ResType, ResName, ResNewName:String);
var Res:TResourceStream;
begin
Res:=TResourceStream.Create(Hinstance, Resname, Pchar(ResType));
try
Res.SavetoFile('.\'+ResNewName); // 释放到当前目录
finally
Res.Free;
end;
end;
6.延时
// 模仿VB里DoEvents的延时
procedure Delay(const uDelay: DWORD);
var
n: DWORD;
begin
n := GetTickCount;
while ( (GetTickCount - n) <= uDelay ) do
Application.ProcessMessages;
end;
procedure Delay(const uDelay: DWORD);
var
n: DWORD;
begin
n := GetTickCount;
while ( (GetTickCount - n) <= uDelay ) do
Application.ProcessMessages;
end;
7.标准C中的 itoa() 函数Delphi版，将Int型变量转化为(radix)进制输出
//二进制 itoa(i, 2);
//八进制 itoa(i, 8);
//十六进制 itoa(i, 16);
function itoa(aData, radix: Integer): String;
var
t: Integer;
begin
Result := '';
repeat
t := aData mod radix;
if t < 10 then
Result := InttoStr(t)+Result
else
Result := InttoHex(t, 1)+Result;
aData := aData div radix;
until (aData = 0);
end;
//八进制 itoa(i, 8);
//十六进制 itoa(i, 16);
function itoa(aData, radix: Integer): String;
var
t: Integer;
begin
Result := '';
repeat
t := aData mod radix;
if t < 10 then
Result := InttoStr(t)+Result
else
Result := InttoHex(t, 1)+Result;
aData := aData div radix;
until (aData = 0);
end;
8.程序删除自身
// 利用批处理文件构造一个循环，只要在 OnClose() 中调用 DeleteMe() 就可以删除自身
procedure DeleteMe();
var
BatchFile: TextFile;
BatchFileName: string;
ProcessInfo: TProcessInformation;
StartUpInfo: TStartupInfo;
begin
BatchFileName := ExtractFilePath(ParamStr(0)) + '_deleteme.bat';
AssignFile(BatchFile, BatchFileName);
Rewrite(BatchFile);
Writeln(BatchFile, ':try');
Writeln(BatchFile, 'del "' + ParamStr(0) + '"');
Writeln(BatchFile,
'if exist "' + ParamStr(0) + '"' + ' goto try');
Writeln(BatchFile, 'del %0');
CloseFile(BatchFile);
FillChar(StartUpInfo, SizeOf(StartUpInfo), $00);
StartUpInfo.dwFlags := STARTF_USESHOWWINDOW;
StartUpInfo.wShowWindow := SW_HIDE;
if CreateProcess(nil, PChar(BatchFileName), nil, nil, False, IDLE_PRIORITY_CLASS, nil, nil, StartUpInfo, ProcessInfo) then
begin
CloseHandle(ProcessInfo.hThread);
CloseHandle(ProcessInfo.hProcess);
end;
end;
procedure DeleteMe();
var
BatchFile: TextFile;
BatchFileName: string;
ProcessInfo: TProcessInformation;
StartUpInfo: TStartupInfo;
begin
BatchFileName := ExtractFilePath(ParamStr(0)) + '_deleteme.bat';
AssignFile(BatchFile, BatchFileName);
Rewrite(BatchFile);
Writeln(BatchFile, ':try');
Writeln(BatchFile, 'del "' + ParamStr(0) + '"');
Writeln(BatchFile,
'if exist "' + ParamStr(0) + '"' + ' goto try');
Writeln(BatchFile, 'del %0');
CloseFile(BatchFile);
FillChar(StartUpInfo, SizeOf(StartUpInfo), $00);
StartUpInfo.dwFlags := STARTF_USESHOWWINDOW;
StartUpInfo.wShowWindow := SW_HIDE;
if CreateProcess(nil, PChar(BatchFileName), nil, nil, False, IDLE_PRIORITY_CLASS, nil, nil, StartUpInfo, ProcessInfo) then
begin
CloseHandle(ProcessInfo.hThread);
CloseHandle(ProcessInfo.hProcess);
end;
end;
