How to create a normal win32 edit control

c++winapi

I'm trying to create an edit control with the regular 3D border around it (in the classic windows style, anyway), but it just has a 1px black border around it. Here is my CreateWindowEx call:

return CreateWindowEx(0, "EDIT", "E:\\bk",
                      WS_VISIBLE | WS_CHILD | WS_BORDER | ES_LEFT,
                      87, 81, 150, 17,
                      main_window.hwnd,
                      (HMENU)5, hInstance, NULL);

If I exclude WS_BORDER then it's just a white box. Any ideas on what's wrong here?

Update

WS_EX_CLIENTEDGE did the trick.
I don't know anything about manifest files, or how to make the window use the more modern windows themes (XP, for example), instead of the chunky 3D borders. But, when I do learn all that, will WS_EX_CLIENTEDGE make them use those themes instead, or will it enforce the 3D look?

Best Solution

Try using WS_EX_CLIENTEDGE. That will create an inset 3-D window border under typical situations.

return CreateWindowEx(WS_EX_CLIENTEDGE, "EDIT", "E:\\bk",
                      WS_VISIBLE | WS_CHILD | WS_BORDER | ES_LEFT,
                      87, 81, 150, 17,
                      main_window.hwnd,
                      (HMENU)5, hInstance, NULL);

Also see the following link for the rest of the available flags for CreateWindowEx.

CreateWindowEx at MSDN

Related Solutions

How to determine the size of the array in C

Executive summary:

int a[17];
size_t n = sizeof(a)/sizeof(a[0]);

Full answer:

To determine the size of your array in bytes, you can use the sizeof operator:

int a[17];
size_t n = sizeof(a);

On my computer, ints are 4 bytes long, so n is 68.

To determine the number of elements in the array, we can divide the total size of the array by the size of the array element. You could do this with the type, like this:

int a[17];
size_t n = sizeof(a) / sizeof(int);

and get the proper answer (68 / 4 = 17), but if the type of a changed you would have a nasty bug if you forgot to change the sizeof(int) as well.

So the preferred divisor is sizeof(a[0]) or the equivalent sizeof(*a), the size of the first element of the array.

int a[17];
size_t n = sizeof(a) / sizeof(a[0]);

Another advantage is that you can now easily parameterize the array name in a macro and get:

#define NELEMS(x)  (sizeof(x) / sizeof((x)[0]))

int a[17];
size_t n = NELEMS(a);

C++ – How to set, clear, and toggle a single bit

Setting a bit

Use the bitwise OR operator (|) to set a bit.

number |= 1UL << n;

That will set the nth bit of number. n should be zero, if you want to set the 1st bit and so on upto n-1, if you want to set the nth bit.

Use 1ULL if number is wider than unsigned long; promotion of 1UL << n doesn't happen until after evaluating 1UL << n where it's undefined behaviour to shift by more than the width of a long. The same applies to all the rest of the examples.

Clearing a bit

Use the bitwise AND operator (&) to clear a bit.

number &= ~(1UL << n);

That will clear the nth bit of number. You must invert the bit string with the bitwise NOT operator (~), then AND it.

Toggling a bit

The XOR operator (^) can be used to toggle a bit.

number ^= 1UL << n;

That will toggle the nth bit of number.

Checking a bit

You didn't ask for this, but I might as well add it.

To check a bit, shift the number n to the right, then bitwise AND it:

bit = (number >> n) & 1U;

That will put the value of the nth bit of number into the variable bit.

Changing the nth bit to x

Setting the nth bit to either 1 or 0 can be achieved with the following on a 2's complement C++ implementation:

number ^= (-x ^ number) & (1UL << n);

Bit n will be set if x is 1, and cleared if x is 0. If x has some other value, you get garbage. x = !!x will booleanize it to 0 or 1.

To make this independent of 2's complement negation behaviour (where -1 has all bits set, unlike on a 1's complement or sign/magnitude C++ implementation), use unsigned negation.

number ^= (-(unsigned long)x ^ number) & (1UL << n);

unsigned long newbit = !!x;    // Also booleanize to force 0 or 1
number ^= (-newbit ^ number) & (1UL << n);

It's generally a good idea to use unsigned types for portable bit manipulation.

number = (number & ~(1UL << n)) | (x << n);

(number & ~(1UL << n)) will clear the nth bit and (x << n) will set the nth bit to x.

It's also generally a good idea to not to copy/paste code in general and so many people use preprocessor macros (like the community wiki answer further down) or some sort of encapsulation.