如何使用无效指针在结构中包装其他类型

如何解决如何使用无效指针在结构中包装其他类型

今晚早些时候我有一个计划，现在变成了一片混乱……我认为我缺少一些基本概念。

这里是个主意： 我必须通过uart发送一些如下所示的内容：

rpmL.txt="10"

vbatt.txt="20.4"

info.txt="Low Temperature"

battIcon.pic='8'

足够简单，对吧？

现在，我有一堆不同的东西，都具有相同的格式，但是唯一改变的是：

rpmL,vbatt,etc.

txt（可以是txt或pic）

10,20.4,Low Temperature,8（可以是int或float或字符串或枚举...您将在下面看到该枚举）

所以，我的想法是，仅创建一个具有所有可以更改的所有类型的typedef的结构，然后再创建一个包含一堆此类typedef的“事物”的结构。

无论如何，这是代码，我只是想根据其类型以不同的方式增加内容：

screen.h

typedef enum _ScreenType{
    T_INT,T_FLOAT,T_CHAR,T_TEMP_ICON,T_BATT_ICON
} ScreenType;

typedef enum _tempIcon{
  TEMP_LOW = 0,TEMP_MED,TEMP_HIGH,//Add More Elements Up Here
  TEMP_MAX_ELEMENTS
}TempIcon;

typedef enum _battIcon{
  BATT_ZERO = 0,BATT_TWENTY_FIVE,BATT_FIFTY,BATT_SEVENTY_FIVE,BATT_FULL,//Add More Elements Up Here
  BATT_MAX_ELEMENTS
}BattIcon;

// Jam everything together so we can just pass the memeber of the following struct to the LCD TX function
typedef struct _packedStringVars{
  ScreenType ScreenType;  // I think I need this to achieve some crude polymorphism later on...
  void* var;  //I think I should do this because this can be a float,int or char*...
  char* label;  //This is always a string...nothing special about this.
}packedStringVars;

typedef struct{
  packedStringVars temp;
  packedStringVars wattage;
  packedStringVars battPercent;
  packedStringVars rpmL;
  packedStringVars rpmR;
  packedStringVars vbat;
  packedStringVars tempIcon;
  packedStringVars battIcon;
}mainScreenVariables;

这是来源：

screen.c

#include "screen.h"
#include ..........Everything Else that You Would Expect.......

//This is where I'm trying to 'initialize' the values...I was doing *(int*) and *(float*),etc.,but that went nowhere...
mainScreenVariables screenData = {
  .temp        = {T_INT,"temp"},.wattage     = {T_INT,"watts"},.rpmL        = {T_INT,"rpmL"},.rpmR        = {T_INT,"rpmR"},.vbat        = {T_FLOAT,"vbat"},.tempIcon    = {T_TEMP_ICON,(TempIcon*)TEMP_LOW,"p1"},.battIcon    = {T_BATT_ICON,(BattIcon*)BATT_FULL,"battIcon"}
};

static void updateValues(void)
{
// As you can see,now i'm typecasting them as I'm using them,which feels all kinds of wrong and also,as it turns out,doesn't even work!  surprise surprise....
    *(int*)screenData.temp.var++;
    *(int*)screenData.wattage.var++;
    *(int*)screenData.battPercent.var++;
    *(int*)screenData.rpmL.var++;
    *(int*)screenData.rpmR.var++;
    *(float*)screenData.vbat.var+=0.1;
   *(TempIcon*)screenData.tempIcon.var++;
    *(ScreenType*)screenData.battIcon.var++;
}

还有更多代码可确保枚举不会超出其范围，等等，但是实际上，我要做的只是设置此概念性的 object ，并将其发送到UART ，其功能签名如下所示：

void ForChristsSakesJustSendTheDamnString(screenData * dat);

我敢肯定，有一些更好的，惯用的方式可以做到这一点。这完全失控了，只是感觉错误。

谢谢！