c - 从指针数组返回字符串的函数

Question

我需要声明一个从指针数组返回字符串的函数..我正在对PIC进行编程，并且我正在使用LCD作为接口(interface).. 有了这段代码，我就得到了我想要的:

// CONFIGURATION BITS
#pragma config FOSC = HS   // Oscillator Selection bits (XT oscillator)
#pragma config WDTE = OFF  // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = OFF // Brown-out Reset Enable bit (BOR disabled)
#pragma config LVP = OFF   // Low-Voltage In-Circuit Serial Programming Enable bit
#pragma config CPD = OFF   // Data EEPROM Memory Code Protection bit 
#pragma config WRT = OFF   // Flash Program Memory Write Enable bits 
#pragma config CP = OFF    // Flash Program Memory Code Protection bit

#define _XTAL_FREQ 8000000

// DEFINING LCD PINS
#define RS RD2
#define EN RD3
#define D4 RD4
#define D5 RD5
#define D6 RD6
#define D7 RD7

#include <xc.h>

#include "lcd.h"

#include <stdio.h>
#include <stdlib.h>

void main()
{

    TRISD = 0x00;           //PORTD as output for LCD
    Lcd_Init();
    Lcd_Clear();

    while(1)
    {

        Lcd_Set_Cursor(1,1);

        char *keypress;
        int key = 2;
        char *key2[] = {"3", "4", "5"}; 
        keypress = key2[key];

        Lcd_Write_String(keypress);

        __delay_ms(50);

    }
}

我得到“5”..这就是我想要的..但​​是当我尝试为此创建一个函数时..

// CONFIGURATION BITS
#pragma config FOSC = HS   // Oscillator Selection bits (XT oscillator)
#pragma config WDTE = OFF  // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = OFF // Brown-out Reset Enable bit (BOR disabled)
#pragma config LVP = OFF   // Low-Voltage In-Circuit Serial Programming Enable bit
#pragma config CPD = OFF   // Data EEPROM Memory Code Protection bit 
#pragma config WRT = OFF   // Flash Program Memory Write Enable bits 
#pragma config CP = OFF    // Flash Program Memory Code Protection bit

#define _XTAL_FREQ 8000000

// DEFINING LCD PINS
#define RS RD2
#define EN RD3
#define D4 RD4
#define D5 RD5
#define D6 RD6
#define D7 RD7

#include <xc.h>

#include "lcd.h"

#include <stdio.h>
#include <stdlib.h>

char kbd_getc();

char kbd_getc(){

    int key = 2;
    char *key2[] = {"3", "4", "5"}; 
    return key2[key];

}

void main()
{

    TRISD = 0x00;           //PORTD as output for LCD
    Lcd_Init();
    Lcd_Clear();

    while(1)
    {

        Lcd_Set_Cursor(1,1);

        char *keypress;

        keypress = kbd_getc();

        Lcd_Write_String(keypress);

        __delay_ms(50);

    }
}

我不明白为什么我会得到 mm ..我不确定我是否错误地声明了函数或者我对指针做了错误的操作，谢谢

Answer 1

你的函数返回char，但你返回一个char *。

将返回类型更改为char *

并提高编译器警告以捕获这些内容。