Qt: How to add resource file (such as image)

It is common that we need to add some images in our widget/form/control to create a good application layout. We can do this by inserting into the widget, the image directly or create a resource file as well. Resource file in the Qt Application is .qrc file.

In a simple shot, we use the resource file by firstly create the file, and include the files into the Qt Application project, and compiling the application.


Ho to do that in detail?

pengingat instruksi di linux

Sekedar untuk mengingat perintah-perintah yang perlu.

RUTIN
- melihat daftar file di suatu folder: ls
- mengkopi file: cp [nama file] [tujuan dir]
- mengubah nama file/memindahkan file: mv [namafilelama] [lokasibaru][namafilebaru]

- membuat direktori baru: mkdir [namafolder] , untuk membuat writable tambahkan
argumen -m770 (kode oktal hak akses), contoh mkdir -m770 test
- mengkopi semua isi folder (subfolder maupun isinya) dg atribute yg sama (akses, dsb)
cp -r -p [folder sumber] [folder tujuan]
- menghapus direktori: rmdir [nama folder]
- melihat total penggunaan memori:free -m
- melihat resource yg dipakai oleh seluruh proses: ps aux
- melihat aplikasi yg sedang berjalan: top
- membersihkan layar: clear
- mengecek ip komputer lokal: ifconfig -a
- masuk ke suatu sub direktori/folder: cd [nama folder]
- keluar dari terminal : exit
- menuju lokasi absolut folder: dahului dengan karakater slash atau "/" misal /usr/bin/



APLIKASI
- mengeksekusi sebuah file executable: ./[nama file]
- melihat file dependency sebuah aplikasi: ldd .[nama file]
- membuat sebuah paket/file instalasi siap running: chmod +x [nama file].bin
- mengganti owner sebuah file: chown
- mengekstraks file .gz: gunzip
- menjalankan aplikasi dengan super user: sudo


referensi lain:
http://pemula.linux.or.id/pengguna/command.html

Data type Range

Data type range.

Below find out the list of data type range for C++. I got the list from MSDN: ttp://msdn.microsoft.com/en-us/library/s3f49ktz(VS.71).aspx

Type Name	Bytes	Other Names	Range of Values
int	*	signed, signed int	System dependent
unsigned int	*	unsigned	System dependent
__int8	1	char, signed char	–128 to 127
__int16	2	short, short int, signed short int	–32,768 to 32,767
__int32	4	signed, signed int	–2,147,483,648 to 2,147,483,647
__int64	8	none	–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
char	1	signed char	–128 to 127
unsigned char	1	none	0 to 255
short	2	short int, signed short int	–32,768 to 32,767
unsigned short	2	unsigned short int	0 to 65,535
long	4	long int, signed long int	–2,147,483,648 to 2,147,483,647
unsigned long	4	unsigned long int	0 to 4,294,967,295
enum	*	none	Same as int
float	4	none	3.4E +/- 38 (7 digits)
double	8	none	1.7E +/- 308 (15 digits)
long double	10	none	1.2E +/- 4932 (19 digits)

Data Conversion

Below is several notes on Data Conversion: something funny that we need regularly.

---------------------------
1. FLOAT TO STRING

use this function:
_gcvt

the format is
char *_gcvt( double value, int digits, char *buffer );

value: the floating point number we wish to convert.
digits: number of decimal place.
buffer: storage location for result


to use it, take a look at this sample:

char buffer[50];
double source = -3.1415e5;
_gcvt( source, 2, buffer );

then, we have buffer that we can treat as string value.