description.cpp

《基于symbian os 的手机开发与应用》 源代码 何伟 著

	// Description.cpp
	// All rights reserved.
	//Author: LiuLiping
	// version 1.0
	// Date: 2006-2-12
	// This program demostrate how to use TBuf,TBufC,TPtrandTPtrC.

#include <e32cons.h>
LOCAL_D CConsoleBase* console; 			// All messages written to this
void callExampleL();					// Function prototypes
void doExampleL();
void useTBuf();
void useTBufC();
void useTPtr();
void useTPtrC();
void WaitForKey()
	{
	_LIT(KMessage,"Press any key to continue\n\n");
	console->Printf(KMessage);
	console->Getch();
	}
void useTBuf()
{
	console->Printf(_L("\n*****useTBuf*****\n"));
	_LIT(KMessage1,"There are cats");
    _LIT(KMessage2," and dogs.");
	_LIT(KMessage3,"white ");
	_LIT(KMessage4,"black ");
	_LIT(KMessage5,"HBufC alloc length is %d");
	_LIT(KMessage6,"HBufC ReAlloc length is %d");
	_LIT(KMessage7,"The fisrt address of buf is %x");
	_LIT(KEnter,"\n");
	TBuf<40> buf;					//定义一个TBuf类对象buf
	buf=KMessage1;					//初始化buf
	console->Printf(buf);			//打印buf
	console->Printf(KEnter);
	buf.Append(KMessage2);			//在buf末尾添加KMessage2
	console->Printf(buf);
	console->Printf(KEnter);
	buf.Insert(10,KMessage3);		//从buf第10位开始查如今KMessage3
	buf.Insert(25,KMessage4);		//从buf第25位开始查如今KMessage4
	console->Printf(buf);
	console->Printf(KEnter);
	HBufC* hbufc = HBufC::New(40);	//定义一个HBufC类的指针hbufc
	hbufc = buf.Alloc();			//初始化hbufc
	TPtr ptr1 = hbufc->Des();		//把不可改变的hbufc变为可改变的描述符赋给ptr通过ptr来对hbufc进行改变的操作
	console->Printf(ptr1);
	console->Printf(KEnter);
	console->Printf(KMessage5,ptr1.MaxLength());//打印HBufC的初始最大长度
	console->Printf(KEnter);
	WaitForKey();
	hbufc->ReAlloc(50);
	TPtr ptr2 = hbufc->Des();
	console->Printf(KMessage6,ptr2.MaxLength());//打印HBufC重新分配后的最大长度
	console->Printf(KEnter);
	WaitForKey();
	console->Printf(KMessage7,buf.Ptr());		//打印buf的起始地址
	console->Printf(KEnter);
	WaitForKey();
}
void useTBufC()
{
	console->Printf(_L("*****useTBufC*****\n"));
	_LIT(KMessage1,"There are flowers");
    _LIT(KMessage2," and trees.");
	_LIT(KMessage3,"buautiful ");
	_LIT(KMessage4,"HBufC alloc length is %d");
	_LIT(KMessage5,"HBufC ReAlloc length is %d");
	_LIT(KMessage6,"The fisrt address of bufc is %x");
	_LIT(KEnter,"\n");
	TBufC<40> bufc;				//定义一个TBufC类的对象bufc
	bufc=KMessage1;				//初始化bufc
	console->Printf(bufc);		//打印bufc
	console->Printf(KEnter);
	TPtr ptr = bufc.Des();		//把不可改变的bufc变为可改变的描述符赋给ptr通过ptr来对bufc进行改变的操作
	ptr.Append(KMessage2);
	console->Printf(bufc);
	console->Printf(KEnter);
	ptr.Insert(10,KMessage3);
	console->Printf(bufc);
	console->Printf(KEnter);
	HBufC* hbufc = HBufC::New(40);
	hbufc = bufc.Alloc();
	TPtr ptr1 = hbufc->Des();
	console->Printf(ptr1);
	console->Printf(KEnter);
	console->Printf(KMessage4,ptr1.MaxLength());
	console->Printf(KEnter);
	WaitForKey();
	hbufc->ReAlloc(50);
	TPtr ptr2 = hbufc->Des();
	console->Printf(KMessage5,ptr2.MaxLength());
	console->Printf(KEnter);
	WaitForKey();
	console->Printf(KMessage6,bufc.Ptr());
	console->Printf(KEnter);
	WaitForKey();
}
void useTPtr()
{
	console->Printf(_L("*****useTPtr*****\n"));
	_LIT(KMessage1,"There are pandas");
    _LIT(KMessage2," and deers.");
	_LIT(KMessage3,"small lovely ");
	_LIT(KMessage4,"HBufC alloc length is %d");
	_LIT(KMessage5,"HBufC ReAlloc length is %d");
	_LIT(KMessage6,"The fisrt address of ptr is %x");
	_LIT(KEnter,"\n");
	TBufC<40> bufc(KMessage1);  //定义一个TBufC类的对象bufc并用KMessage1来初始化bufc
    TPtr16 ptr(bufc.Des());		//定义一个TPtr16类的对象并用bufc来初始化它
	console->Printf(ptr);		//打印ptr
	console->Printf(KEnter);
	WaitForKey();
	ptr.Append(KMessage2);
	console->Printf(ptr);
	console->Printf(KEnter);
	ptr.Insert(10,KMessage3);
	console->Printf(ptr);
	console->Printf(KEnter);
	HBufC* hbufc = HBufC::New(40);
	hbufc = ptr.Alloc();
	TPtr ptr1 = hbufc->Des();
	console->Printf(ptr1);
	console->Printf(KEnter);
	console->Printf(KMessage4,ptr1.MaxLength());
	console->Printf(KEnter);
	WaitForKey();
	hbufc->ReAlloc(50);
	TPtr ptr2 = hbufc->Des();
	console->Printf(KMessage5,ptr2.MaxLength());
	console->Printf(KEnter);
	WaitForKey();
	console->Printf(KMessage6,ptr.Ptr());
	console->Printf(KEnter);
	WaitForKey();
}
void useTPtrC()	//因为TPtrC类没有函数Des()所以该类是不可改变的
{
	console->Printf(_L("*****useTPtrC*****\n"));
	_LIT(KMessage1,"There are books");
	_LIT(KMessage2,"HBufC alloc length is %d");
	_LIT(KMessage3,"HBufC ReAlloc length is %d");
	_LIT(KMessage4,"The fisrt address of ptrc is %x");
	_LIT(KEnter,"\n");
    TPtrC ptrc(KMessage1);			//定义一个TPtrC类的对象ptrc并用KMessage1初始化它
	console->Printf(ptrc);			//打印ptrc
	console->Printf(KEnter);
	HBufC* hbufc = HBufC::New(40);
	hbufc = ptrc.Alloc();
	TPtr ptr1 = hbufc->Des();
	console->Printf(ptr1);
	console->Printf(KEnter);
	console->Printf(KMessage2,ptr1.MaxLength());
	console->Printf(KEnter);
	hbufc->ReAlloc(50);
	TPtr ptr2 = hbufc->Des();
	console->Printf(KMessage3,ptr2.MaxLength());
	console->Printf(KEnter);
	console->Printf(KMessage4,ptrc.Ptr());
	console->Printf(KEnter);
}

GLDEF_C TInt E32Main()
{
	
   CTrapCleanup* cleanup=CTrapCleanup::New();	// Get cleanup stack
   TRAPD(error,doExampleL());					// callExampleL() should never leave.
   _LIT(KMsgPanicEpoc32ex,"EPOC32EX");
   __ASSERT_ALWAYS(!error,User::Panic(KMsgPanicEpoc32ex,error));
   delete cleanup;								// destroy the cleanup stack
   return 0;									// return
    }
void doExampleL()				//doExample() and CallExample()
	{
  	_LIT(KPressAnyKey,"[Press any key...OK]");
							//Get Console;
	_LIT(KMsgExampleCode,"Symbian OS Example Code");
	console = Console::NewL(KMsgExampleCode,TSize(KConsFullScreen,KConsFullScreen));
							//Put console onto the cleanup stack.
	CleanupStack::PushL(console);
	int error;
	TRAP(error,callExampleL());	//TRAPD(error,callExampleL());
	if(error)
	{
		_LIT(KERROR,"error occured!\n");
		console->Printf(KERROR);
	}
	console->Printf(KPressAnyKey);
	console->Getch();
	CleanupStack::PopAndDestroy();
}
void callExampleL() 
    {
        useTBuf();
		useTBufC();
		useTPtr();
		useTPtrC();
	}