pointer of array show out problem

Dear All,
how to textout the value of pointer of array?
Thank u

It is simple:

char *p = "hello world";

You can do that
for(i = 0; i < strlen(p); i++)
cout << p[i];
or
while(*p)
{
cout << *p;
p++;
}

With integer values you do
int mas[10];
int *p = mas;

for(i = 0; i < 10; i++)
{
cout << p[i];
}

Quote:

---

Originally quoted by lwong
how to textout the value of pointer of array?

---

Are you talking about the TextOut function in the CDC class?

TDM

Yes.TDM

You need a pointer to a char array and x and y values that represents the upper left corner of where the text will be displayed.

Code:

---

CClientDC dc(this);
char *Text=new char[128];
strcpy(Text,"Test string");
dc.TextOut(10,10,Text,strlen(Text));
delete []Text;

---

The above would display the string 'Test string' 10 pixels from the top and 10 pixels from the left of the client area defined by the DC.

Code:

---

CClientDC dc(this);

CRect WndRect;
GetClientRect(&WndRect);

char* Text=new char[128];
strcpy(Text,"Test string");

CFont NewFont;
NewFont.CreatePointFont(100,"Courier New",&DC);
CFont * OldFont=dc.SelectObject(&NewFont);

CSize TextSize=dc.GetTextExtent(Text,strlen(Text));

CPoint TextPoint;
TextPoint.cx=(WndRect.CenterPoint().x-(TextSize.cx/2));
TextPoint.cy=(WndRect.CenterPoint().y-(TextSize.cy/2));

dc.TextOut(TextPoint.cx,TextPoint.cy,Text,strlen(Text));

dc.SelectObject(OldFont);
delete []Text;

---

The above would display the string 'Test string' in the center of the client area in a Courier New font with a point size of 10.

Hope that helps.

TDM

One thing that was not mentioned was what type of array you were using....float, char, int...etc. If you need to display a non-character array, tThe previous post would need to be modified to convert a non-char array to characters before TextOut will work.

TDM

TDM,
if the pointer of array is not the type of char, but is float, how to convert between them?

PHP Code:

---

template <class T>
std::string convert_to_string(T t, std::ios_base & (*f)(std::ios_base&), const  std::streamsize precision)
{
    std::ostringstream oss;
    oss <<std::fixed<<std::setprecision(precision)<< f << t;
    return oss.str();
};

//from std::string to a number
template <class T>
bool convert_from_string(T &t, const std::string &s, std::ios_base & (*f)(std::ios_base&), const  std::streamsize precision)
{
    std::istringstream iss(s);
    return !(iss>>f>>std::setprecision(precision)>>std::fixed>>t).fail();
}; 


---

Say you have

PHP Code:

---

double my_number = 7.9;
std::string as_string(convert_to_string(my_number, std::dec, 10)); 


---

is an example of doing the conversion.

PHP Code:

---

    CPaintDC dc(this); // device context for painting
CRect WndRect;
GetClientRect(&WndRect);
dc.SaveDC();
double my_number = 1.22223444;
std::string as_string(convert_to_string(my_number, std::dec, 10));

CFont NewFont;
NewFont.CreatePointFont(100,"Courier New",&dc);
dc.SelectObject(&NewFont);

CSize TextSize=dc.GetTextExtent(as_string.c_str(), as_string.length());

CPoint TextPoint;
TextPoint.x=(WndRect.CenterPoint().x-(TextSize.cx/2));
TextPoint.y=(WndRect.CenterPoint().y-(TextSize.cy/2));

dc.TextOut(TextPoint.x,TextPoint.y,as_string.c_str(), as_string.length());

dc.RestoreDC(-1); 


---

Hi,

Using the least complicated of my 2 previous examples: I assume you already have an array I'll use 'FloatArray' as the name in the example. You'll also need to update the X and Y values in the TextOut function somehow. Just for this example I'm going to keep the same Y and add 10 to the X in each iteration in the loop.

Code:

---

CClientDC dc(this);
int ArraySize=10,Xplace=10,YPlace=10;

CString Text;

for(int i=0;i<ArraySize;i++)
{
    Text.Format("%f",FloatArray[i]);
    dc.TextOut(XPlace+=10,YPlace,Text);
}

---

Hope that helps

TDM

Putting scale labels on the tick marks of the graph? If you're doing this in OnPaint or OnDraw don't use CClientDC use the DC in those functions.

TDM

CString :rolleyes: :D

Quote:

---

Originally quoted by souldog
CString :rolleyes: :D

---

You don't like CString?

TDM

I was just kidding around. However, I try to minimize my use of
MFC as much as possible.

Thanks TDM, this is what i want.

One thing to be aware of:

Quote:

---

Originally posted by souldog

Code:

---

CPaintDC dc(this);

---

---

That's the correct way for obtaining a DC for painting from a WM_PAINT handler.

Quote:

---

Originally posted by TDM

Code:

---

CClientDC dc(this);

---

---

Caution - that code uses an unprepared DC for drawing to the window's client area - it will be slower and might lead to flickering or even update problems, depending on where you call it.

Just in case you intend to copy the code as posted - watch out for that pitfall, and rather use the code as posted by souldog.

Yah, I guess I should point out I ran that code in a WM_PAINT
handler for a dialog to make sure it worked. (TDM's code actually
had some small errors)

Also the following includes are needed in the header for the
templates and string
#include <string>
#include <sstream>
#include <iostream>
#include <iomanip>

I kinda had the feeling CString would be used so I was a bit sloppy :)

(I guess I just wanted to show how to do it right (with the standard) and definitely not with new char[].)

Oh boy here we go again...I love it

Quote:

---

Originally quoted by gstercken
Just in case you intend to copy the code as posted - watch out for that pitfall.

---

In a previous post I clearly stated to use DC provided in the WM_PAINT handler if he is putting his drawing code in the WM_PAINT handler.

In most cases doing painting in the WM_PAINT handler is the way to go because the window may only need to be repainted if it is resized or clipped by another window. You will have the benefits of only having the invalidated portions of the window to redrawn. I don't deny that....never have.

Of course there are instances where doing all drawing in the WM_PAINT handler is not the most efficient and flicker free way to go.................

TDM

Quote:

---

Originally posted by TDM
In most cases doing painting in the WM_PAINT handler is the way to go because the window may only need to be repainted if it is resized or clipped by another window. You will have the benefits of only having the invalidated portions of the window to redrawn. I don't deny that....never have.

---

So we finally seem to agree on this... :)

Look, most of the window-redrawing problems posted here can be tracked down to a wrong understanding of the repainting mechanism, and they are usually related to using CClientDC or GetDC() called from the wrong place - that's why I think it's important to propagate the 99,5% case (using CPaintDC in a WM_PAINT handler or the pDC passed in OnDraw) for any drawing code. A code sample using CClientDC is very likely to set people on the wrong track and lead to lots of problems in the future, that's why I commented on the code samples posted above.