基本上我想做的就是拿出我已经声明的三个温度传感器读数并将它们组合成一个数组。从那时起，我希望能够增加数组中每个相应变量的值，具体取决于用户选择的当前通道，这是一个名为selectChannel的变量
所以如果用户在频道0上，并且他们按下R，我希望temperatureSensor1Reading增加。 @icktoofay提到使用指针，我做了他们推荐的更改但是当我按r或f时，没有增加温度。
enter code here
#include "stdafx.h"
#include <Windows.h> //additional header added to allow for coloured text
#include "console.h"
#include <conio.h>
#include "lab4temperatureController.h"
#include <time.h>
//#define hConsole
#define CH1 0
#define CH2 1
#define CH3 2
temperature_t selectChannel = 0;
temperature_t temperatureSensor1Reading = 75;
temperature_t temperatureSensor2Reading = 75;
temperature_t temperatureSensor3Reading = 75;
temperature_t *temperatureSensorReadings[3] = {&temperatureSensor1Reading, &temperatureSensor2Reading, &temperatureSensor3Reading};
//Update Display:---------------------
//Description: prints out readings and updates with increment, decrement and average
//
//Parameters: lowlimit, highlimit, temperatures, Channels
//
//
//Returns:
//
//------------------------------------------------------------------
void updateDisplay()
{
clrscr();
HANDLE hConsole; //standard c library call
hConsole = GetStdHandle(STD_OUTPUT_HANDLE); //used for output screen buffer to allow for coloured text
SetConsoleTextAttribute(hConsole, 2); //sets output screen colour for following text
printf("\nCurrent Temperature for channel 1 is %d\n\n", temperatureSensor1Reading);
printf("Upper Limit for channel 1 is %d\n\n", getHighLimit(CH1));
printf("Lower Limit for channel 1 is %d\n\n", getLowLimit(CH1));
setCurrentTemperature(CH1, temperatureSensor1Reading);
SetConsoleTextAttribute(hConsole, 3); //sets output screen colour for following body of text
printf("Current Temperature for channel 2 is %d\n\n", temperatureSensor2Reading);
printf("Upper Limit for channel 2 is %d\n\n", getHighLimit(CH2));
printf("Lower Limit for channel 2 is %d\n\n", getLowLimit(CH2));
setCurrentTemperature(CH2, temperatureSensor2Reading);
SetConsoleTextAttribute(hConsole, 4); //sets output screen colour for following body of text
printf("Current Temperature for channel 3 is %d\n\n", temperatureSensor3Reading);
printf("Upper Limit for channel 3 is %d\n\n", getHighLimit(CH3));
printf("Lower Limit for channel 3 is %d\n\n", getLowLimit(CH3));
setCurrentTemperature(CH3, temperatureSensor3Reading);
compareMinLimit(CH1);
compareMinLimit(CH2);
compareMinLimit(CH3);
compareHighLimit(CH1);
compareHighLimit(CH2);
compareHighLimit(CH3);
if (isAverageValid() == TRUE)
{
//if average is valid call function to calculate average and print returned value
//SetConsoleTextAttribute(hConsole, 5); //sets output screen colour for following text
printf("average for channel 1 is %d\n\n", calculateAverageTemperature(CH1));
printf("average for channel 2 is %d\n\n", calculateAverageTemperature(CH2));
printf("average for channel 3 is %d\n\n", calculateAverageTemperature(CH3));
//--if average is valid call functions to determine min and max values and print returned values for each channel
temperature_t max1 = calculateMax(CH1);
temperature_t min1 = calculateMin(CH1);
temperature_t max2 = calculateMax(CH2);
temperature_t min2 = calculateMin(CH2);
temperature_t max3 = calculateMax(CH3);
temperature_t min3 = calculateMin(CH3);
printf("the maximum temperature is: %d \n \nthe minimum temperature is: %d \n \n", max1,min1); //display each channels max/min
printf("the maximum temperature is: %d \n \nthe minimum temperature is: %d \n \n ", max2,min2);
printf("the maximum temperature is: %d \n \nthe minimum temperature is: %d \n \n", max3,min3);
// if average is valid call function to print histogram
SetConsoleTextAttribute(hConsole, 15);
printf("the following is the pressure histogram for channel %d \n \n", selectChannel+1);
printPressureHistogram(selectChannel);
//print out the current channels histograms
//initializeTemperatureSubsystem();
}
}
//main:---------------------
//Description: initializes the temperature subsystem and provides user with various input commands
// which can be used to increment, decrement and get average value of temperatures
//Parameters: lowlimit, highlimit, temperatures, MAXSAMPLES
//
//Returns:
//------------------------------------------------------------------
int _tmain(int argc, _TCHAR* argv[])
{
// -- insert variable declaration for time ------
time_t timeOfLastStoredSample, currentTime;
//==============================================
initializeTemperatureSubsystem();
//--insert code to store the initial sensor temperature------
recordCurrentTemperature(CH1, temperatureSensor1Reading); //records each channels temperature reading
recordCurrentTemperature(CH2, temperatureSensor2Reading);
recordCurrentTemperature(CH3, temperatureSensor3Reading);
//--record the time as timeOfLastSample
timeOfLastStoredSample = time(NULL);
//==========================================
printf("\n Q,A: Adjust the current temperature select, W,S adjust our limit, E,D adjust lower limit \n");
unsigned char quit = 'n'; //binds quit to literal value of 'n'
while(quit == 'n') //executes until user quits
{
//-- insert code to get currentTime----
time(¤tTime); //ASK ABOUT THIS (we haev to explicitly direct time to the address for current time
//--insert code to compare the two time values and see if 20 seconds have elapse
if (currentTime - timeOfLastStoredSample >= 1)
{
//if 20 seconds have elapsed, record the time and update value held by timeLastStoredSample
recordCurrentTemperature(CH1, temperatureSensor1Reading);
recordCurrentTemperature(CH2, temperatureSensor2Reading);
recordCurrentTemperature(CH3, temperatureSensor3Reading);
time(&timeOfLastStoredSample);
}
updateDisplay();
Sleep(200);
unsigned char selectedCommand = 0;
if( _kbhit() )
{
selectedCommand = _getch();
switch(selectedCommand)
{
case 'Q': //if user input is Q
case 'q'://if user input is q
selectChannel ++;
if (selectChannel > 2) //determine which channel the user is on, if greater than 2, then cycle to channel 0
selectChannel = CH1;
printf ("\n your current channel is %d \n \n ", selectChannel + 1);
break; //exits loop
case 'A': //if user input is A
case 'a'://if user input is a
selectChannel --;
if (selectChannel < 0) //determine which channel the user is on, if less than 0, then cycle to channel 2
selectChannel = CH3;
printf (" \n your current channel is %d \n \n", selectChannel + 1);
break; //exits loop
case 'R': //if user input is R
case 'r'://if user input is r
*temperatureSensorReadings[selectChannel]++;
break; //exits loop
case 'F': //if user input is 'F'
case 'f': //if user input is 'f'
*temperatureSensorReadings[selectChannel]--;
break; //exits loop
case 'W': //if user input is 'W'
case 'w': //if user input is 'w'
increaseHighLimit(selectChannel); //increase CH1 high limit
break; //exits loop
case 'S':
case 's'://if user input is 'S
decreaseHighLimit(selectChannel); //decrement CH1 high limit
break; //exits loop
case 'E':
case 'e': //if user input is E
increaseLowLimit(selectChannel); //decrement CH1 low limit
break; //exits loop
case'D':
case'd': //if user input is D
decreaseLowLimit(selectChannel); //decrement CH1 lowlimit
break;//exits loop
case'X': //conditions apply for preceding case as well (for upper and lowercase "q")
clrscr(); //executes function
gotoxy(2,2); //returns command line to 2,2 location
printf("Exiting...Bye!\n");
quit = 'y'; //cause exit of while loop
break;
default:
clrscr(); //executes function
gotoxy(1,1); //takes command line to location 1,1
printf("Q,A: Adjust the current temperature select, W,S adjust our limit, E,D adjust lower limit \n");
break;
}//eo of switch
}//eo kbhit()
}// eo while loop
return 0;
}
答案 0 :(得分：2)
问题出现在temperature_t *temperatureSensorReadings[3]中，这是以一种非常奇怪的方式声明的。
当您使用*temperatureSensorReadings[selectChannel]++;增加（或减少）温度时，您不会增加存储在数组中的温度值，而是指向该值的指针。然后指针指向未分配的空间，导致未定义的行为。
使用正确的括号将解决该问题
( *temperatureSensorReadings[selectChannel] )++;
正确的解决方案是将数组声明为：
temperature_t temperatureSensor1Reading = 75;
temperature_t temperatureSensor2Reading = 75;
temperature_t temperatureSensor3Reading = 75;
temperature_t temperatureSensorReadings[3] = { temperatureSensor1Reading, temperatureSensor2Reading, temperatureSensor3Reading};
更改行，将值增加到更简单的代码
case 'R': //if user input is R
case 'r'://if user input is r
temperatureSensorReadings[selectChannel]++;
这当然意味着更改可能依赖于此数组的所有其他代码。