[DELPHI]接口和类的一个范例代码
Type{接口和类申明:区别在于不能在接口中申明数据成员、任何非公有的方法、公共方法不使用PUBLIC关键字}
Isample=interface//定义Isample接口
function getstring:string;
end;
Tsample=class(TInterfacedObject,Isample)
public
function getstring:string;
end;
//function定义
function Tsample.getstring:string;
begin
result:='what show is ';
end;
//调用类对象
var sample:Tsample;
begin
sample:=Tsample.create;
showmessage(sample.getstring+'class object!');
sample.free;
end;
//调用接口
var sampleinterface:Isample;
sample:Tsample;
begin
sample:=Tsample.create;
sampleInterface:=sample;//Interface的实现必须使用class
{以上两行也可表达成sampleInterface:=Tsample.create;}
showmessage(sampleInterface.getstring+'Interface!');
//sample.free;{和局部类不同,Interface中的类自动释放}
sampleInterface:=nil;{释放接口对象}
end;
[DELPHI]任务条就看不当程序
var
ExtendedStyle : Integer;
begin
Application.Initialize;
ExtendedStyle := GetWindowLong (Application.Handle, GWL_EXSTYLE);
SetWindowLong(Application.Handle, GWL_EXSTYLE, ExtendedStyle OR WS_EX_TOOLWINDOW AND NOT WS_EX_APPWINDOW);
Application.CreateForm(TForm1, Form1);
Application.Run;
end.
[DELPHI]ALT+CTRL+DEL看不到程序
在implementation后添加声明:
function RegisterServiceProcess(dwProcessID, dwType: Integer): Integer; stdcall; external 'KERNEL32.DLL';
RegisterServiceProcess(GetCurrentProcessID, 1);//隐藏
RegisterServiceProcess(GetCurrentProcessID, 0);//显示
[DELPHI]检测光驱符号
var drive:char;
cdromID:integer;
begin
for drive:='d' to 'z' do
begin
cdromID:=GetDriveType(pchar(drive+':\'));
if cdromID=5 then showmessage('你的光驱为:'+drive+'盘!');
end;
end;
[DELPHI]检测声卡
if auxGetNumDevs()<=0 then showmessage('No soundcard found!') else showmessage('Any soundcard found!');
[DELPHI]在字符串网格中画图
StringGrid.OnDrawCell事件
with StringGrid1.Canvas do
Draw(Rect.Left, Rect.Top, Image1.Picture.Graphic);
[SQL SERVER]SQL中代替Like语句的另一种写法
比如查找用户名包含有"c"的所有用户, 可以用
use mydatabase
select * from table1 where username like'%c%"
下面是完成上面功能的另一种写法:
use mydatabase
select * from table1 where charindex('c',username)>0
这种方法理论上比上一种方法多了一个判断语句,即>0, 但这个判断过程是最快的, 我想信80%以上的运算都是花在查找字
符串及其它的运算上, 所以运用charindex函数也没什么大不了. 用这种方法也有好处, 那就是对%,|等在不能直接用like
查找到的字符中可以直接在这charindex中运用, 如下:
use mydatabase
select * from table1 where charindex('%',username)>0
也可以写成:
use mydatabase
select * from table1 where charindex(char(37),username)>0
ASCII的字符即为%
[DELPHI]SQL显示多数据库/表
SELECT DISTINCT A.bianhao,a.xingming, b.gongzi FROM "jianjie.dbf" a, "gongzi.DBF" b
WHERE A.bianhao=b.bianhao
[DELPHI]RFC(Request For Comment)相关
IETF(Internet Engineering Task Force)维护RFC文档http://www.ietf.cnri.reston.va.us
RFC882:报文头标结构
RFC1521:MIME第一部分,传输报文方法
RFC1945:多媒体文档传输文档
[DELPHI]TNMUUProcessor的使用
var inStream,outStream:TFileStream;
begin
inStream:=TFileStream.create(infile.txt,fmOpenRead);
outStream:=TFileStream(outfile.txt,fmCreate);
NMUUE.Method:=uuCode;{UUEncode/Decode}
//NMUUE.Method:=uuMIME;{MIME}
NMUUE.InputStream:=InStream;
NMUUE.OutputStream:=OutStream;
NMUUE.Encode;{编码处理}
//NMUUE.Decode;{解码处理}
inStream.free;
outStream.free;
end;
[DELPHI]TFileStream的操作
//从文件流当前位置读count字节到缓冲区BUFFER
function read(var buffer;count:longint):longint;override;
//将缓冲区BUFFER读到文件流中
function write(const buffer;count:longint):longint;override;
//设置文件流当前读写指针为OFFSET
function seek(offset:longint;origin:word):longint;override;
origin={soFromBeginning,soFromCurrent,soFromEnd}
//从另一文件流中当前位置复制COUNT到当前文件流当前位置
function copyfrom(source:TStream;count:longint):longint;
//读指定文件到文件流
var myFStream:TFileStream;
begin
myFStream:=TFileStream.create(OpenDialog1.filename,fmOpenRead);
end;
[JavaScript]检测是否安装IE插件Shockwave&Quicktime
var myPlugin = navigator.plugins["Shockwave"];
if (myPlugin)
document.writeln("你已经安装了 Shockwave!")
else
document.writeln("你尚未安装 Shockwave!")
var myPlugin = navigator.plugins["Quicktime"];
if (myPlugin)
document.writeln("你已经安装了Quicktime!")
else
document.writeln("你尚未安装 Quicktime!")
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