C++ :: Checking If Key With Modifier Pressed?
Jan 31, 2015I am new to C++ , i want to know how to check if a key with modifier is pressed.
When I use GetAsyncKeyState() it gives me error identifier not found.
I am new to C++ , i want to know how to check if a key with modifier is pressed.
When I use GetAsyncKeyState() it gives me error identifier not found.
double &val = 66.6; //illegal
const double &val = 66.6; //legal
I was just doing some demo programs and came through the above concept but not able to identify what exactly the need of the above concept . what magic exactly const is doing in the second case ?
Where exactly we can use this concept in real time programming ?
I have created a program to calculate different measurements for a cylinder. Anyways, the end user has to input 3 variables.
Enter the lower radius: 6
Enter the upper radius: 5
Enter slant height: 2.236
The numbers are what "End User" would input. But I need to make it look like this when said "End User inputs the numbers.
Enter the lower radius: 6
Enter the upper radius: 5
Enter slant height: 2.236
Here is what I have for it, but I don't know what to put where.
printf("
Enter the lower radius: ");
scanf("%f", &lower_rad);
printf("Enter the upper radius: ");
scanf("%f", &upper_rad);
printf("Enter slant height: ");
scanf("%f", &slant_h);
if we don't provide the acces modifiers for base class and we need to manipulate the private data of base class in derived class. Is there anyway to acces the private data members? Here's a coding example
class A {
private :
int a;
};
class B : public class A {
public :
void displayA() { cout<<a<<endl; }
};
how i can acces the a of base class A in derived class B without acces modifiers.
The following 2 codes are almost identical, only that the switch statements are slightly different. The 2nd code has the issue of requiring an additional enter key to be pressed when I enter '3' as input to exit the program.
Working code :
Code:
#include <stdio.h>
#include <ctype.h>
#include <string.h>
void clearKeyboardBuffer() {
int ch;
while ((ch = getchar() != '
[code]....
I need to run some operation if a key from keyboard is pressed. so I go with
Code: c=getchar();
to get it read. yet the user could press a key anytime; so I'd need some if-loop. no plans on how it'd look like though...I suppose something like this below wouldn't work right?
Code:
if(getchar()==1){
..
}
I know how to check if a particular button has been pressed but I basically want to disable the delete button when ever the listbox has lost focus. I am having issues with the fact the button gets disabled before it receives the message. Is their a way around this that is non hacky?
BOOL CALLBACK DlgMain(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch(uMsg)
{
[Code]....
How would I detect if any letter key is pressed. Would I have to use GetAsyncKeyState() for every letter key? Or could I have some kind of loop going through all the hexadecimal values for every letter? I don't know how I would go through hexadecimal values with a loop.
View 6 Replies View RelatedSo I'm in the process of building my 2D game in Allegro5, I'm building a side platform game and at the moment I have a sprite being able to walk left right and jump. What I want to do is put a time delay on the jump function so that when a user presses the jump button and the sprite has carried out the jump function I want there to be a 1 or so second delay before the jump button actually carries out the jump function again.
I have quite a bit of code so not sure what bits to place in here, I'm more looking for a way of doing this, so providing me code isnt really needed just a way it can be done.
Things that might be useful to know:
At the moment I have a timer initialized in allegro which is used with my FPS int to mean that my game runs at 60FPS.
I have a bool bIsOnGround which maybe could be used into this, I'm not sure...
I have been learning C# so I've been dragging and dropping. I have a "First Name" and "Last Name" text field. I want to add this to a combo box called something like "User List", which will list the last named then the first names. However I figure I can work with something that can get me to store the names in the combo box.
So. I have two things I need to know:
What do I have to do to have when the button is pressed, add to the combo box?
Is there a way to retain all the entries I have entered? Or no?
So, I've been working on a project recently, and the only thing remaining to do is a detector to whenever down arrow key is pressed. The down arrow key can only trigger when a certain check box is checked and this will have to work with a timer either. The problem is that how to make the down arrow key press detector(I've got the check box and timer ready tho).
View 10 Replies View RelatedI would like to know how to press a key as if it had been pressed on the keyboard in a program. I would also like to know how to read input from a xbox 360 controller. I want to know how to do this so that I can add joystick support to a few mmos that I play that do not already have it.
BTW I am using C 99
I Like to Open a Dialog When the Button Was Pressed for 5 seconds Continuously.
I'm using Windows 8 HP Tablet, Is MouseUp & MouseDown events suitable for this requirement.
I am currently using Flash. Here are two images I will be referring through without this post:
1: [URL] ....
2: [URL] ....
So basically, when I click the generate buttonon the first image it takes you to the second image. What I want is when I click the generate button it comes to this screen, aswell as choose a random word from each list that I will make (Who List, What List, When List, Where List, and Why List) and place the word next to its position. When you click New Idea I want it to also generate another set of random words from the lists. How can I do this?
My code is given below:
cout<<"1. runtim";
cout<<"2.tims";
cout<<"Your selection will be automatically neglected within (function to be inserted for time ) ";/* insert timer here */
cout<<"What kind of process u need to do";
.
.
.
.
I have 2 questions
1.the timer function has to be such that when any key is pressed in between the specified time its has to stop its counting and go to the nest line and functions . i checked sleep function but if any key is pressed its does not break out of the sleep program and execute the next command
2.and if the timer has completely finished running then it has to skip few lines and execute the program .
In a SDI app, I constraint the mouse to move only an horizontal direction, if "Shift" key is pressed ... here is the code:
Code:
void CTestMouseView::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags) {
// TODO: Add your message handler code here and/or call default
if(GetKeyState(VK_SHIFT) < 0) {
CRect rect;
GetWindowRect(&rect);
GetCursorPos(&m_point);
[Code] ....
Nothing complicated, and it works well ... except one thing: when I press the shift key and the mouse is moving by SetCursorPos, is moving pretty slow ... why ? I can not figure out why ! For testing, I attached the test project ...
I usually check if a bit is set using:
Code: bit = (number >> n) & 1; where `n` is the bit I want to check...
But I came across a stackoverflow answer saying:
bit = number & (1 << x); will not put the value of bit x into bit unless bit has type _Bool (<stdbool.h>).
Otherwise, bit = !!(number & (1 << x)); will..
So why is this? why the double !?
Everything seems to be correct from my perspective. heres the program: Code: /*c program to check whether a string is palindrome or not*/
#include<stdio.h>
#include<string.h>
int main(void) {
char str[30];
int i,j,flag=0;
[Code] .....
The reason being is that it says that my program is right
Code:
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#define NFlights 10
struct date {
int month;
int day;
int year;
int hour;
int minute;
[Code] ....
Q. In context of C language syntax checking, which of the following can be modeled using Finite Automata?
(A) Detecting proper termination of an instruction.
(B) Detecting balance of parentheses.
(C) Detecting initialization of a variable.
(D) None of the above.
I think I may have found a new way of checking for 3d polygon collisions, but I'm not sure. The method involves...
1. finding the planes that the primitives lie on
2. finding the line where the planes intersect
3. if both polys have points on both sides of the line AND have points that overlap on the 1d space of the line, then they intersect.
I have some half done code testing this, and so far it seems to be sound and fairly fast. These are some average time-tests done on my machine for each part:
1. 30 microseconds (both)
2. 7 microseconds
3. TBD
I have a question, how can I check if a program is running using c++? For example
if (notepad.exe is running) {
.... ..... ....
How would I go about checking for deallocated memory?
For example, let's take this into consideration:
// Unsigned 32-bit / 64-bit integer: uint32, uint64
uint32* Pointer = new uint32[ Size ];
uint64 MemAddr = ( uint64 ) Pointer;
delete[] Pointer;
The above code would proceed to create a new array, store it in a pointer and retrieve the memory address of the array before finally deleting the array.
So let's assume we re-build the pointer and try to access the now deallocated array:
Pointer = ( uint32* ) MemAddr;
Pointer[ 0 ] = 0;
Based on the above snippets of code, how would I check "Pointer" after rebuilding the memory to check if the rebuilt memory has actually been deallocated. Without a check we'd get an exception error.
A bit of detail on why I am trying this:
Before thinking up how to do this, I was storing the addresses in a list and check the list for the addresses to see if they existed or not. However this requires an O(n) search, which isn't exactly what I am wanting. So instead if I used a check for deallocation method, I can go for an O(1) time check and reduce the total time it would take to check for memory allocation/deallocation.
I have created a prompt which prompts the user for an integer and I have set up a loop to check for if it is an integer or not. My "bug" is that a user can enter an "integer" and "space" and "enter" and it does not give any error and assumes that "All is FINE!". I have gotten the value from the ascii table of 'SPACE' and put it as a check in my parameter of while, but it does not work.
Here is my code:
int x, y, boolean, i;
char buff[256];
printf("Enter the first integer value: ");
scanf("%s", buff);
i = 0;
boolean = 0; //initializing our boolean var that will eventually decide if we have an error or not
[code]....
Suppose you have a templated class, such as
template <typename T>
class Matrix {
// some stuff and some methods
};
and let's say that you have some methods that need to do some type-dependent stuff, like, for example,
template <typename T>
Matrix<T> Matrix<T>::transpose() const {
// get this->rowCount, this->columnCount
// create a Matrix that has rowCount amount of columns and columnCount amount of rows
// copy (*this)[j][k] to theMatrix[k][j] (for all of the entries in *this)
// if the entries are complex, take the complex conjugate of them all
}
Would it be good practice to check explicitly for the typename parameter (or is this, somehow, defeating the purpose of templates)? std::cout << "I know that this is a design question, but it needs to be asked... ";
I'm playing around with parts of code and am coming across some errors. Most of my concern is related to strtok(). I've used it before but with a char* named token. I used a while loop to continuously check whether token was equal to NULL. In the following code, however, there aren't any checks. I was wondering if that is why this code prints (null) while running. Also, I would like to know if it is possible to read input like this code attempts to do - assigning tokens to each variable one after the other.
The format of the input:
Zucchini, Squash, pound
Yellow, Squash, pound
Tomatoes, Ugly Ripe, each
#include <stdio.h>
#include <stdlib.h>
[code]....