Also Look At:
I have learnt to read from and write to file, so the database program for my friend has begun in earnest.
It is an extension of the program I posted a while back.
So far the program I am writing has 5046 lines of code in it. Programming can really be fun and at least to me, it is a brain twister I enjoy solving. Right now I am trying to solve the problem of displaying search results coming up dynamically as the user types in an item information. The results show in the lower part of the screen if the search results are less than 10.
I can do it for one value (Say Item ID), but what if the user types half of item ID and some characters of the name?
Anyway, the database program uses the following style extensively. It is a menu that the user can navigate around using the arrow keys. Like I always say, this may not be the best way to do it, but I don't know better. I'm just glad I could come up with code to do this, and right now I don't care if it is badly written code.
Although I haven't included in this example, a lot of things I use in my original program, let me mention that for the "Age" field I would include a check to make sure user is entering digits.
Something like: if(y==1 && a<9 && key>=48 && key <=57)
This example also uses the header myconstdwin.h. Click on it, copy paste the code to a notepad file, save it as "myconstdwin.h", copy paste the file into the include folder for codeblocks (the path on my computer is C:\Program Files\CodeBlocks\MinGW\include). Once you have the file in there, this program will compile and run.
More information on the get_key() function to detect the function and arrow keys etc. can be found in my previous post.
For this particular program, the user can enter the name, or maybe just half of the name, then decide to enter sex or age, using the DOWN arrow key to move from one menu item to another, I haven't included the UP arrow key to keep the program short. Backspace can be used for correction. The program will also make sure user does not exceed the array value when entering the values. For example, user can only enter 29 characters for 'Name', after that user is informed that they cannot enter more characters.
Later we can atoi the age, if we intend to use it numerically, before using it.
Finally hitting enter will show all the entered values.
Sample:
#include <myconstdwin.h>
void dl_hl(int x,int y);
int get_key();
main()
{
int key,n=0,a=0,s=0,x,y=0; //since y, which is the verticle row, starts at 0
char name[30],age[10],sex[15];
gotoxy(0,10);
printf("Hit Enter To See Values, Down Arrow key to navigate.");
gotoxy(0,0);
SetColorAndBackground(15,0); //bright white
printf("Name\t- \n");
SetColorAndBackground(8,0); //normal grey
printf("Age\t- \n");
printf("Sex\t- ");
gotoxy(10,0);
x=10; //in gotoxy, x will be 10 in the beginning
while(1)
{
key=get_key();
{
/**If user hits the down key**/
if(key==592)
{
if(y==0) //y(row) is 0, IE at 'name'
{
dl_hl(1,2); //dehighlight 1(name) highlight 2(age)
y=1; //y is now at age
x=10+a;
gotoxy(10+a,1); //move to cursor to one after the age field
//+number of chars entered
}
else if(y==1) //y(row) is 1, that means highlight is at age
{
dl_hl(2,3); //dehighlight 2(age) highlight 3(sex)
y=2; //y is now at sex
x=10+s;
gotoxy(10+s,2); //move to cursor to one after the sex field
//+number of chars entered
}
else if(y==2) //y(row) is 2, that means highlight is at sex
{
dl_hl(3,1); //dehighlight 3(sex) highlight 1(name)
y=0; //y is now at name
x=10+n;
gotoxy(10+n,0); //move to cursor to one after the name field + number
//of characters entered
}
}
/** User enters VALID CHARACTERS **/
else if(key>=32 && key<=126) //valid characters
{
if(y==0 && n<29) //name is highlighted. characters less than 30
{
printf("%c",key);
name[n]=key; //the particular block is assigned the key entered
n++; //n is incremented, ready to accept the next key user
x=10+n;
}
else if(n==29) //name can only hold 29 characters. The last one is for
//the terminating \0 NULL character
{
gotoxy(0,5);
printf("Out of characters. 29 or less characters!");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
if(y==1 && a<9) //age is highlighted. characters less than 10
{
printf("%c",key);
age[a]=key; //the particular block is assigned the key entered
a++; //n is incremented, ready to accept the next key user
x=10+a;
}
else if(a==9) //age can only hold 9 characters. The last one is for
//the terminating \0 NULL character
{
gotoxy(0,5);
printf("Out of characters. 9 or less characters!");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
if(y==2 && s<14) //sex is highlighted. characters less than 10
{
printf("%c",key);
sex[s]=key; //the particular block is assigned the key entered
s++; //n is incremented, ready to accept the next key user
x=10+s;
}
else if(s==14) //sex can only hold 14 characters. The last one is for
//the terminating \0 NULL character
{
gotoxy(0,5);
printf("Out of characters. 14 or less characters!");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
}
/**If user hits the Backspace key**/
else if(key==8)
{
if(y==0 && n>0) //if cursor is in name and characters are entered
{
/*move cursor one back, then blank it out by printing a space
then go back again. Effectively, the last character is erased*/
printf("\b \b");
n--; //number of characters for name is decremented
x=10+n; //re-assign x for gotoxy.
}
else if(y==1 && a>0)
{
/*move cursor one back, then blank it out by printing a space
then go back again. Effectively, the last character is erased*/
printf("\b \b");
a--; //number of characters for age is decremented
x=10+a; //re-assign x for gotoxy.
}
else if(y==2 && s>0)
{
/*move cursor one back, then blank it out by printing a space
then go back again. Effectively, the last character is erased*/
printf("\b \b");
s--; //number of characters for age is decremented
x=10+s; //re-assign x for gotoxy.
}
}
/**User hits enter key**/
else if(key==13)
{
if(n==0 && a==0 && s==0)
{
gotoxy(0,5);
printf("Enter values first");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else if(n==0)
{
gotoxy(0,5);
printf("Enter Name");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else if(a==0)
{
gotoxy(0,5);
printf("Enter Age");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else if(s==0)
{
gotoxy(0,5);
printf("Enter Sex");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else
{
/**everything is entered. Make sure everything has
the terminating character so that they are valid strings**/
name[n]='\0';
age[a]='\0';
sex[s]='\0';
gotoxy(0,5);
printf("Name: %s\nAge: %s\nSex: %s\n",name,age,sex);
getch();
break;
}
}
}
}
}
void dl_hl(int x,int y)
{
if(x==1)
{
gotoxy(0,0);
SetColorAndBackground(8,0);
printf("Name\t-");
}
else if(y==1)
{
gotoxy(0,0);
SetColorAndBackground(15,0);
printf("Name\t-");
SetColorAndBackground(8,0);
}
if(x==2)
{
gotoxy(0,1);
SetColorAndBackground(8,0);
printf("Age\t-");
}
else if(y==2)
{
gotoxy(0,1);
SetColorAndBackground(15,0);
printf("Age\t-");
SetColorAndBackground(8,0);
}
if(x==3)
{
gotoxy(0,2);
SetColorAndBackground(8,0);
printf("Sex\t-");
}
else if(y==3)
{
gotoxy(0,2);
SetColorAndBackground(15,0);
printf("Sex\t-");
SetColorAndBackground(8,0);
}
}
int get_key()
{
int c = getch(); //first getch() sees the first value
switch (c) //This will only take action if the value is 0 or 224
{
case 0: return getch()+256; //and this second getch() eats the 2nd value
case 224: return getch()+512; //and 256 or 512 is added to it and returned.
}
return c; //if the value is not 0 or 224 (IE key is not special) normal value is returned
}
I have learnt to read from and write to file, so the database program for my friend has begun in earnest.
It is an extension of the program I posted a while back.
So far the program I am writing has 5046 lines of code in it. Programming can really be fun and at least to me, it is a brain twister I enjoy solving. Right now I am trying to solve the problem of displaying search results coming up dynamically as the user types in an item information. The results show in the lower part of the screen if the search results are less than 10.
I can do it for one value (Say Item ID), but what if the user types half of item ID and some characters of the name?
Anyway, the database program uses the following style extensively. It is a menu that the user can navigate around using the arrow keys. Like I always say, this may not be the best way to do it, but I don't know better. I'm just glad I could come up with code to do this, and right now I don't care if it is badly written code.
Although I haven't included in this example, a lot of things I use in my original program, let me mention that for the "Age" field I would include a check to make sure user is entering digits.
Something like: if(y==1 && a<9 && key>=48 && key <=57)
This example also uses the header myconstdwin.h. Click on it, copy paste the code to a notepad file, save it as "myconstdwin.h", copy paste the file into the include folder for codeblocks (the path on my computer is C:\Program Files\CodeBlocks\MinGW\include). Once you have the file in there, this program will compile and run.
More information on the get_key() function to detect the function and arrow keys etc. can be found in my previous post.
For this particular program, the user can enter the name, or maybe just half of the name, then decide to enter sex or age, using the DOWN arrow key to move from one menu item to another, I haven't included the UP arrow key to keep the program short. Backspace can be used for correction. The program will also make sure user does not exceed the array value when entering the values. For example, user can only enter 29 characters for 'Name', after that user is informed that they cannot enter more characters.
Later we can atoi the age, if we intend to use it numerically, before using it.
Finally hitting enter will show all the entered values.
Sample:
#include <myconstdwin.h>
void dl_hl(int x,int y);
int get_key();
main()
{
int key,n=0,a=0,s=0,x,y=0; //since y, which is the verticle row, starts at 0
char name[30],age[10],sex[15];
gotoxy(0,10);
printf("Hit Enter To See Values, Down Arrow key to navigate.");
gotoxy(0,0);
SetColorAndBackground(15,0); //bright white
printf("Name\t- \n");
SetColorAndBackground(8,0); //normal grey
printf("Age\t- \n");
printf("Sex\t- ");
gotoxy(10,0);
x=10; //in gotoxy, x will be 10 in the beginning
while(1)
{
key=get_key();
{
/**If user hits the down key**/
if(key==592)
{
if(y==0) //y(row) is 0, IE at 'name'
{
dl_hl(1,2); //dehighlight 1(name) highlight 2(age)
y=1; //y is now at age
x=10+a;
gotoxy(10+a,1); //move to cursor to one after the age field
//+number of chars entered
}
else if(y==1) //y(row) is 1, that means highlight is at age
{
dl_hl(2,3); //dehighlight 2(age) highlight 3(sex)
y=2; //y is now at sex
x=10+s;
gotoxy(10+s,2); //move to cursor to one after the sex field
//+number of chars entered
}
else if(y==2) //y(row) is 2, that means highlight is at sex
{
dl_hl(3,1); //dehighlight 3(sex) highlight 1(name)
y=0; //y is now at name
x=10+n;
gotoxy(10+n,0); //move to cursor to one after the name field + number
//of characters entered
}
}
/** User enters VALID CHARACTERS **/
else if(key>=32 && key<=126) //valid characters
{
if(y==0 && n<29) //name is highlighted. characters less than 30
{
printf("%c",key);
name[n]=key; //the particular block is assigned the key entered
n++; //n is incremented, ready to accept the next key user
x=10+n;
}
else if(n==29) //name can only hold 29 characters. The last one is for
//the terminating \0 NULL character
{
gotoxy(0,5);
printf("Out of characters. 29 or less characters!");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
if(y==1 && a<9) //age is highlighted. characters less than 10
{
printf("%c",key);
age[a]=key; //the particular block is assigned the key entered
a++; //n is incremented, ready to accept the next key user
x=10+a;
}
else if(a==9) //age can only hold 9 characters. The last one is for
//the terminating \0 NULL character
{
gotoxy(0,5);
printf("Out of characters. 9 or less characters!");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
if(y==2 && s<14) //sex is highlighted. characters less than 10
{
printf("%c",key);
sex[s]=key; //the particular block is assigned the key entered
s++; //n is incremented, ready to accept the next key user
x=10+s;
}
else if(s==14) //sex can only hold 14 characters. The last one is for
//the terminating \0 NULL character
{
gotoxy(0,5);
printf("Out of characters. 14 or less characters!");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
}
/**If user hits the Backspace key**/
else if(key==8)
{
if(y==0 && n>0) //if cursor is in name and characters are entered
{
/*move cursor one back, then blank it out by printing a space
then go back again. Effectively, the last character is erased*/
printf("\b \b");
n--; //number of characters for name is decremented
x=10+n; //re-assign x for gotoxy.
}
else if(y==1 && a>0)
{
/*move cursor one back, then blank it out by printing a space
then go back again. Effectively, the last character is erased*/
printf("\b \b");
a--; //number of characters for age is decremented
x=10+a; //re-assign x for gotoxy.
}
else if(y==2 && s>0)
{
/*move cursor one back, then blank it out by printing a space
then go back again. Effectively, the last character is erased*/
printf("\b \b");
s--; //number of characters for age is decremented
x=10+s; //re-assign x for gotoxy.
}
}
/**User hits enter key**/
else if(key==13)
{
if(n==0 && a==0 && s==0)
{
gotoxy(0,5);
printf("Enter values first");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else if(n==0)
{
gotoxy(0,5);
printf("Enter Name");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else if(a==0)
{
gotoxy(0,5);
printf("Enter Age");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else if(s==0)
{
gotoxy(0,5);
printf("Enter Sex");
getch();
/*erase the message*/
gotoxy(0,5);
printf(" ");
gotoxy(x,y); //cursor moves back to where it was
}
else
{
/**everything is entered. Make sure everything has
the terminating character so that they are valid strings**/
name[n]='\0';
age[a]='\0';
sex[s]='\0';
gotoxy(0,5);
printf("Name: %s\nAge: %s\nSex: %s\n",name,age,sex);
getch();
break;
}
}
}
}
}
void dl_hl(int x,int y)
{
if(x==1)
{
gotoxy(0,0);
SetColorAndBackground(8,0);
printf("Name\t-");
}
else if(y==1)
{
gotoxy(0,0);
SetColorAndBackground(15,0);
printf("Name\t-");
SetColorAndBackground(8,0);
}
if(x==2)
{
gotoxy(0,1);
SetColorAndBackground(8,0);
printf("Age\t-");
}
else if(y==2)
{
gotoxy(0,1);
SetColorAndBackground(15,0);
printf("Age\t-");
SetColorAndBackground(8,0);
}
if(x==3)
{
gotoxy(0,2);
SetColorAndBackground(8,0);
printf("Sex\t-");
}
else if(y==3)
{
gotoxy(0,2);
SetColorAndBackground(15,0);
printf("Sex\t-");
SetColorAndBackground(8,0);
}
}
int get_key()
{
int c = getch(); //first getch() sees the first value
switch (c) //This will only take action if the value is 0 or 224
{
case 0: return getch()+256; //and this second getch() eats the 2nd value
case 224: return getch()+512; //and 256 or 512 is added to it and returned.
}
return c; //if the value is not 0 or 224 (IE key is not special) normal value is returned
}
No comments:
Post a Comment