new in a class (for string)

Please help me!!

How can i make a string in a class dynamicly.
i want to put the input from the keyboard in a TempString and search the StringTerminator to build the dynamic string in the class. pleas help!!

I tried to make it but it return every time:

sizeof(CharArray) == 4

// Define Class

class TestClass
{
private:
char *CharArray;
public:
void Set_CharArray(char* Temp);
void Get_CharArray();

TestClass (int Size);
~TestClass ();
};

// define Methode

void TestClass::Set_CharArray(char* Temp)
{
strcpy(CharArray,Temp);
}

void TestClass::Get_CharArray()
{
cout<<sizeof(CharArray)<<endl;
cout<<CharArray<<endl;
}

// Define Constructor

TestClass::TestClass(int Size)
{
CharArray = new char [Size+1];
CharArray[0]='\0';
cout<<sizeof(CharArray)<<endl;
}

// Define Destructor

TestClass::~TestClass()
{
delete CharArray;
}