我尝试从Firestore下载的ArrayList>中存储以前的新项目。下载过程正在运行，但是在编辑列表后，我无法再次上传，因为firestore表示它必须是Map。因此我尝试使用
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct s
{
char *value;
} S;
S list[2];
void function( )
{
char val1[] = "val1";
char val2[] = "val2";
//Note that you are creating a copy of "val1" here which can be avoided by changing it to char *val1 = "val1";
list[0].value = malloc(strlen(val1)+1); //allocate space for val1 + NUL-terminator
strcpy(list[0].value, val1); //copy string
list[1].value = malloc(strlen(val2)+1);
strcpy(list[1].value, val2);
//You could also use the function strdup which allocates memory and duplicates the string
//list[0].value = strdup(val1);
printf("%s\n", list[1].value); //prints val2
}
int main(int argc, char** argv)
{
function();
printf("%s", list[1].value);
free(list[0].value); //Don't forget to free.
free(list[1].value);
return 0;
}
问题是如果我使用此代码，它说不支持嵌套数组。这是完整的代码：
Map<String, Object> listValue = new HashMap<>();
listValue.put("shoppingLists", Arrays.asList(shoppingLists));