|
lately i am finding that I am adding functions in the public space only.. no protected no private.. may be just to access the functions easily.. how may i remove this habbit.
tell me true practical explaination that private or protected are must
pathak
|
|
|
|
|
You can do one thing. Create a variable in the public scope that is critical to your application and you don't want the user to modify value of the same.
If this value gets modified you are stuck.
Don't allow to do this.
You will have to think the criticallity of the variable each time you are going to declare them and at the same time you need to determine their scope
Somethings seem HARD to do, until we know how to do them.
_AnShUmAn_
|
|
|
|
|
Practices are making man perfect.
so through practice, u will be perfect.
Reading is a good option to know more and correct our assumptions and mistake and also it will fill the gaps in our knowledge.
If you read Code Complete 2, Effective C++ (or similar books), u will find that what u r doing is absolutly wrong.
Define scope for all classes u r creating.
Fix the interfaces, limit it to a minimum.
The public functions are used to communicate with other modules or object. where are as we are defining private functions for some internal calculation required by other functions in the class.
Suppose there is a function in your class which draws an object in your window. you don't need to share this function to others. because it is only required when a paint message comes in your object and draws the required object. it is limited to your class.
so scope ur object with minimum interfaces. never put internal functions to public, that is nto a good way of pragramming. if it is generic and can be used for others make it public static and meaningful.
Hope u clear.
-Sarath
|
|
|
|
|
If you want that no one can access your method simply make it Private
If you want that only immediate derived class can access the methods make it protected
and for everyone make it public
for e.g
if you want that the user must pass the parameter for creation of the instance of the class then make the empty constructer as private
class test
{
public:
test(int index){index=0};
private:
test(){};
};
Knock out 'T' from CAN'T ,
You 'CAN' if you think you 'CAN'
|
|
|
|
|
A_LaXmanKnock out 'T' from CAN'T ,
also " ' "
then it becomes CAN
|
|
|
|
|
Can you start thinking from now?;P
Knock out 'T' from CAN'T ,
You 'CAN' if you think you 'CAN'
|
|
|
|
|
pathakr wrote: tell me true practical explaination that private or protected are must
when you don't any functionality to leak to outer class, which will corrupt the data if not properly used!
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
|
|
|
|
|
Just get in the habbit of always adding new functions in the private section first and only "promote" them to protected or lastly to public when required.
Steve
|
|
|
|
|
I have a parent window, it has a Bitmap(GDI+) data member which draws a picture as background when OnPaint is called.
I create an Edit control and type a string in it. now I want to write the string to the background picture, at the exact position the Edit control be.
how to do that? help please
I ever called DrawText in OnOK, find when OnPaint is called, my string will be covered by background. so I want to make the string be part of background picture, but I don't konw how to do. help, help, help.......
-- modified at 2:39 Thursday 18th May, 2006
|
|
|
|
|
you can see example in msdn
CString str;
CEdit m_Edit1;
m_Edit1.GetWindowText(str);
graphics.DrawString(
A2W(str),
11,
&myFont,
origin,
&blackBrush);
whitesky
-- modified at 2:01 Thursday 18th May, 2006
|
|
|
|
|
in fact, what I realy want is not type string on window directly. I have a Bitmap object, I want add the string into the picture, then every time the picture be drawed(OnPaint function be called), the string will show out.
I want the string to be part of the background picture, splice them as one picture.;)
sorry, my English not very good, sometimes I expressed wrong ideas. thank you.
|
|
|
|
|
Use DrawText or Textout API's
Knock out 'T' from CAN'T ,
You 'CAN' if you think you 'CAN'
|
|
|
|
|
in fact, what I realy want is not type string on window directly. I have a Bitmap object, I want add the string into the picture, then every time the picture be drawed(OnPaint function be called), the string will show out.
I want the string to be part of the background picture, splice them as one picture.
sorry, my English not very good, sometimes I expressed wrong ideas. thank you.
|
|
|
|
|
When you type the text after that you can check the value of Enter Key and set make the edit control transparent.
Cheers
"Peace of mind through Technology"
|
|
|
|
|
like this
<br />
USES_CONVERSION;<br />
Graphics graphics(GetDC()->m_hDC) ;<br />
Image * img ;<br />
ImageAttributes imAttrib; <br />
img = Image::FromFile(A2W("c:\\A.jpg")) ;<br />
graphics.DrawImage(img,Rect(0,0,378,350),<br />
0,0,img ->GetWidth(),img ->GetHeight(),
<br />
CString str;<br />
str="Hello frined";<br />
<br />
Font Font(L"System", 16);<br />
PointF origin(50,50);<br />
SolidBrush Brush(Color(255,255,255));<br />
graphics.DrawString(A2W(str),str.GetLength(),&Font,origin,&Brush);<br />
<br />
whitesky
|
|
|
|
|
sorry, I think I express the wrong idea. please read my reply to other persons. thank you.
|
|
|
|
|
Asking for help!!!
|
|
|
|
|
Please tell me Difference between "C structure" and "C++ structure".
|
|
|
|
|
The variables in C structure are by default public but in C++ they are private
Somethings seem HARD to do, until we know how to do them.
_AnShUmAn_
|
|
|
|
|
is it true that constructor will be called for class but there will be no constructor for the structure
|
|
|
|
|
Structures don't have constructors and how can they be called if they don't exist.
Yes but still what you say is correct. It would be better to initialize the member's of the structure somewhere(more preferrably the constructor of the class) before using them.
Somethings seem HARD to do, until we know how to do them.
_AnShUmAn_
|
|
|
|
|
We may have a Constructer's for C++ Structures(look the Following code)
C++ Structure's can be initialized/copied by overloading the Assignment Operator Like following
struct Mypoint
{
int x,y;
Mypoint() : x(0),y(0){};
const Mypoint &operator = (const Mypoint &me)
{
x=me.x;
y=me.y;
return *this;
};
Knock out 'T' from CAN'T ,
You 'CAN' if you think you 'CAN'
|
|
|
|
|
_AnShUmAn_ wrote: It would be better to initialize the member's of the structure
you can create Construtor in Structure, see the example i have quoted in post above you!
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
|
|
|
|
|
NiLeSh KoRpE wrote: there will be no constructor for the structure
Have a try!
#include<stdio.h>
#include <malloc.h>
struct ab
{
ab()
{
printf("alok");
}
};
main()
{
ab a;
int *hello;
printf("Hi, Enter any value > ");
hello=(int*)malloc(sizeof(int));
scanf("%d",hello);
}
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
|
|
|
|
|
_AnShUmAn_ wrote: The variables in C structure are by default public but in C++ they are private
have you tried that?
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
