none]
8。长度单位
相对单位:
em (em,元素的字体的高度)
ex (x-height,字母 "x" 的高度)
px (像素,相对于屏幕的分辨率)
绝对长度:
in (英寸,1英寸=2.54厘米)
cm (厘米,1厘米=10毫米)
mm (米)
pt (点,1点=1/72英寸)
pc (帕,1帕=12点)
◇[DELPHI]VCL制作简要步骤
1.创建部件属性方法事件
(建立库单元,继承为新的类型,添加属性、方法、事件,注册部件,建立包文件)
2.消息处理
3.异常处理
4.部件可视
◇[DELPHI]动态连接库的装载
静态装载:procedure name;external 'lib.dll';
动态装载:var handle:Thandle;
handle:=loadlibrary('lib.dll');
if handle<>0 then
begin
{dosomething}
freelibrary(handle);
end;
◇[DELPHI]指针变量和地址
var x,y:integer;p:^integer;//指向INTEGER变量的指针
x:=10;//变量赋值
p:=@x;//变量x的地址
y:=p^;//为Y赋值指针P
@@procedure//返回过程变量的内存地址
◇[DELPHI]判断字符是汉字的一个字符
ByteType('你好haha吗',1) = mbLeadByte//是第一个字符
ByteType('你好haha吗',2) = mbTrailByte//是第二个字符
ByteType('你好haha吗',5) = mbSingleByte//不是中文字符
◇[DELPHI]memo的定位操作
memo1.lines.delete(0)//删除第1行
memo1.selstart:=10//定位10字节处
◇[DELPHI]获得双字节字符内码
function getit(s: string): integer;
begin
Result := byte(s[1]) * $100 + byte(s[2]);
end;
使用:getit('计')//$bcc6 即十进制 48326
◇[DELPHI]调用ADD数据存储过程
存储过程如下:
create procedure addrecord(
record1 varchar(10)
record2 varchar(20)
)
as
begin
insert into tablename (field1,field2) values(:record1,:record2)
end
执行存储过程:
EXECUTE procedure addrecord("urrecord1","urrecord2")
◇[DELPHI]将文件存到blob字段中
function blobcontenttostring(const filename: string):string;
begin
with tfilestream.create(filename,fmopenread) do
try
setlength(Result,size);
read(Pointer(Result)^,size);
finally
free;
end;
end;
//保存字段
begin
if (opendialog1.execute) then
begin
sFileName:=OpenDialog1.FileName;
adotable1.edit;
adotable1.fieldbyname('visio').asstring:=Blobcontenttostring(FileName);
adotable1.post;
end;
◇[DELPHI]把文件全部复制到剪贴板
uses shlobj,activex,clipbrd;
procedure Tform1.copytoclipbrd(var FileName:string);
var
FE:TFormatEtc;
Medium: TStgMedium;
dropfiles:PDropFiles;
pFile:PChar;
begin
FE.cfFormat := CF_HDROP;
FE.dwAspect := DVASPECT_CONTENT;
FE.tymed := TYMED_HGLOBAL;
Medium.hGlobal := GlobalAlloc(GMEM_SHARE or GMEM_ZEROINIT, SizeOf(TDropFiles)+length(FileName)+1);
if Medium.hGlobal<>0 then begin
Medium.tymed := TYMED_HGLOBAL;
dropfiles := GlobalLock(Medium.hGlobal);
try
dropfiles^.pfiles := SizeOf(TDropFiles);
dropfiles^.fwide := False;
longint(pFile) := longint(dropfiles)+SizeOf(TDropFiles);
StrPCopy(pFile,FileName);
Inc(pFile, Length(FileName)+1);
pFile^ := #0;
finally
GlobalUnlock(Medium.hGlobal);
end;
Clipboard.SetAsHandle(CF_HDROP,Medium.hGlobal);
end;
end;
◇[DELPHI]列举当前系统运行进程
uses TLHelp32;
procedure TForm1.Button1Click(Sender: TObject);
var lppe: TProcessEntry32;
found : boolean;
Hand : THandle;
begin
Hand := CreateToolhelp32Snapshot(TH32CS_SNAPALL,0);
found := Process32First(Hand,lppe);
while found do
begin
ListBox1.Items.Add(StrPas(lppe.szExeFile));
found := Process32Next(Hand,lppe);
end;
end;
◇[DELPHI]根据BDETable1建立新表Table2
Table2:=TTable.Create(nil);
try
Table2.DatabaseName:=Table1.DatabaseName;
Table2.FieldDefs.Assign(Table1.FieldDefs);
Table2.IndexDefs.Assign(Table1.IndexDefs);
Table2.TableName:='new_table';
Table2.CreateTable();
finally
Table2.Free();
end;
◇[DELPHI]最菜理解DLL建立和引用
//先看DLL source(FILE-->NEW-->DLL)
library project1;
uses
SysUtils, Classes;
function addit(f:integer;s:integer):integer;export;
begin
makeasum:=f+s;
end;
exports
addit;
end.
//调用(IN ur PROJECT)
implementation
function addit(f:integer;s:integer):integer;far;external 'project1';//申明
{调用就是addit(2,4);结果显示6}
◇[DELPHI]动态读取程序自身大小
function GesSelfSize: integer;
var
f: file of byte;
begin
filemode := 0;
assignfile(f, application.exename);
reset(f);
Result := filesize(f);//单位是字节
closefile(f);
end;
◇[DELPHI]读取BIOS信息
with Memo1.Lines do
begin
Add('MainBoardBiosName:'+^I+string(Pchar(Ptr($FE061))));
Add('MainBoardBiosCopyRight:'+^I+string(Pchar(Ptr($FE091))));
Add('MainBoardBiosDate:'+^I+string(Pchar(Ptr($FFFF5))));
Add('MainBoardBiosSerialNo:'+^I+string(Pchar(Ptr($FEC71))));
end;
◇[DELPHI]动态建立MSSQL别名
procedure TForm1.Button1Click(Sender: TObject);
var MyList: TStringList;
begin
MyList := TStringList.Create;
try
with MyList do
begin
Add('SERVER NAME=210.242.86.2');
Add('DATABASE NAME=db');
Add('USER NAME=sa');
end;
Session1.AddAlias('TESTSQL', 'MSSQL', MyList); //ミMSSQL
Session1.SaveConfigFile;
finally
MyList.Free;
Session1.Active:=True;
Database1.DatabaseName:='DB';
Database1.AliasName:='TESTSQL';
Database1.LoginPrompt:=False;
Database1.Params.Add('USER NAME=sa');
Database1.Params.Add('PASSWORD=');
Database1.Connected:=True;
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
Database1.Connected:=False;
Session1.DeleteAlias('TESTSQL');
end;
◇[DELPHI]播放背景音乐
uses mmsystem
//播放音乐
MCISendString('OPEN e:\1.MID TYPE SEQUENCER ALIAS NN', '', 0, 0);
MCISendString('PLAY NN FROM 0', '', 0, 0);
MCISendString('CLOSE ANIMATION', '', 0, 0);
end;
//停止播放
MCISendString('OPEN e:\1.MID TYPE SEQUENCER ALIAS NN', '', 0, 0);
MCISendString('STOP NN', '', 0, 0);
MCISendString('CLOSE ANIMATION', '', 0, 0);
◇[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%,
关键词：DELPHI基础开发技巧