我有一个char数组，我试图将其转换为指向字符串的char指针。我相信这涉及到将指针指向char数组的第一个元素，并在char数组的末尾添加一个空字符。这样做的原因是，我试图将其传递给SimpleMenuItem卵石智能手表的，.title需要在其中获取char*，它指向一个字符串。
虽然我已经能够填充char数组，并且（我认为）添加了空字符并获得了指针，但我仍无法在卵石上看到标题。我不确定这是卵石问题还是我的C理解问题，但是我感到很可能是前者。
卵石代码（C）：
void in_received_handler(DictionaryIterator *received, void *context) {
dataReceived = dict_read_first(received);
APP_LOG(APP_LOG_LEVEL_DEBUG, "read first");
while (dataReceived != NULL){
if (dataReceived->key == 0x20) {
//original is of the format "# random string", i.e. "4 test name"
char* original = dataReceived->value->cstring;
APP_LOG(APP_LOG_LEVEL_DEBUG, original);
char originalArray[strlen(original)];
//copy over to originalArray
for (unsigned int i = 0; i < strlen(original); i++) {
originalArray[i] = original[i];
}
char* keysplit = strtok(originalArray, " ");
APP_LOG(APP_LOG_LEVEL_DEBUG, keysplit);
//key
int key = atoi(keysplit);
APP_LOG(APP_LOG_LEVEL_DEBUG, "Int Key: %d", key);
//good until here
char remainderArray[sizeof(originalArray)-strlen(keysplit) +1];
//assign rest of string to new array
for (unsigned int i = 1; i < sizeof(remainderArray)-1; i++){
APP_LOG(APP_LOG_LEVEL_DEBUG, "Character : %c", originalArray[i+strlen(keysplit)]);
remainderArray[i] = originalArray[i+strlen(keysplit)];
APP_LOG(APP_LOG_LEVEL_DEBUG, "Character in new Array: %c", remainderArray[i]);
}
remainderArray[sizeof(remainderArray)-1] = '\0';
//data is sucesfully placed into remainderArray
char* ptr = remainderArray;
strncpy(ptr, remainderArray, sizeof(remainderArray)+1);
ptr[sizeof(remainderArray)+1] = '\0';
chats[key] = (SimpleMenuItem){
// You should give each menu item a title and callback
.title = &remainderArray[0],
.callback = selected_chat,
};
}
dataReceived = dict_read_next(received);
APP_LOG(APP_LOG_LEVEL_DEBUG, "read again");
}
layer_mark_dirty((Layer *)voice_chats);
}
如果有人对为什么小卵石不显示分配给它的数据有任何建议.title，我希望听到他们的建议。
谢谢！
解决方案实际上比这简单得多。
首先，请注意，char数组和指向字符串的指针实际上是相同的。它们都是指向第一个字节地址的指针。在这两种情况下，系统函数都将搜索空字符以标识字符串的结尾（strlen，strcpy，printf等）。char*并且char[]可以互换。
当您在中接收数据时in_received_handler()，您获得的指针（dataReceived->value->cstring）指向蓝牙接收缓冲区，您需要将该字符串复制到其他位置。这样，每次需要重绘屏幕时，这些字符都将可用。
由于要获取的项目数量是动态的，因此必须使用来动态分配内存malloc()。您应该记得稍后再分配内存（使用free()）。
这将编译并应执行您想要的操作：
void in_received_handler(DictionaryIterator *received, void *context) {
Tuple *dataReceived = dict_read_first(received);
while (dataReceived != NULL){
if (dataReceived->key == 0x20) {
//original is of the format "# random string", i.e. "4 test name"
char* original = dataReceived->value->cstring;
APP_LOG(APP_LOG_LEVEL_DEBUG, original);
char* keysplit = strtok(original, " ");
APP_LOG(APP_LOG_LEVEL_DEBUG, keysplit);
//key
int key = atoi(keysplit);
APP_LOG(APP_LOG_LEVEL_DEBUG, "Int Key: %d", key);
// This will return the second part of the string.
char *message = strtok(NULL, " ");
// Allocate some memory to hold a copy of that message
char *copyOfMessage = malloc(strlen(message));
// And copy the message from the bluetooth buffer to the new memory
strcpy(copyOfMessage, message);
APP_LOG(APP_LOG_LEVEL_DEBUG, "Message: %d", key);
chats[key] = (SimpleMenuItem){
// You should give each menu item a title and callback
.title = copyOfMessage,
.callback = selected_chat,
};
}
dataReceived = dict_read_next(received);
}
layer_mark_dirty((Layer *)voice_chats);
}
顺便说一句，我建议不要使用另一个带有键和消息的字符串，并在客户端的C语言中对其进行解析，而建议您使用另一个应用程序消息键索引来传输您的“键”。例如，您可能有：
{
0x1: 33, // the key
0x20: "message" // the actual message
}
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