客观，麻烦帮忙解释。伪代码如下：
class MyClass{
private:
type* a; //就是这个变量
public:
void Init(); //对a做初始化
void Use() //使用a变量，为null
}
情况补充：
- Init方法是肯定触发了（打印了log）
- Use的方法调用是在类（CCLayer）的通过定时器（CCDirector::sharedDirector…）触发的。
估计是init的时候的问题。
可能是你以一个init函数里面的局部变量，初始化a这个变量的。a是个指针，运行完init函数。局部变量被清除。
a指向就空了。
在use的时候，当然得到的也是空的。
虽然看代码我能知道，不看代码我还真猜不出来 
把init 和 Use 函数定义发出来看看。
亲爱的 shujun.qiao ，代码截图如下
#ifndef HELLOWORLD_SCENE_H
#define HELLOWORLD_SCENE_H
#include “cocos2d.h”
#include “pomelo.h”
#include “cocos-ext.h”
//#include “CocosGUI.h”
#include “DILayer.h”
using namespace cocos2d;
using namespace cocos2d::extension;
class LoginScene : public DILayer
{
private:
pc_client_t* pomelo_client;
const char* sessionID;
public:
// Here’s a difference. Method ‘init’ in cocos2d-x returns bool, instead of returning ‘id’ in cocos2d-iphone
virtual bool init();
virtual void onEnter();
// there’s no ‘id’ in cpp, so we recommend returning the class instance pointer
static cocos2d::CCScene* scene();
// a selector callback
void menuCloseCallback(CCObject* pSender);
static void requstLoginCallback(pc_request_t *req, int status, json_t *resp);
void login(CCObject* obj,TouchEventType tType);
void intoLoddy();
// implement the “static node()” method manually
CREATE_FUNC(LoginScene);
};
#endif // HELLOWORLD_SCENE_H
LoginScene.cpp代码如下
#include “LoginScene.h”
#include “GameLobbyScene.h”
#include “SimpleAudioEngine.h”
using namespace cocos2d;
using namespace cocos2d::extension;
//判断是否登录
static bool isLogin = false;
CCScene* LoginScene::scene()
{
// ‘scene’ is an autorelease object
CCScene *scene = CCScene::create();
// 'layer' is an autorelease object
LoginScene *layer = LoginScene::create();
// add layer as a child to scene
scene->addChild(layer);
// return the scene
return scene;
}
UITextField* txtNickname;
// on “init” you need to initialize your instance
bool LoginScene::init()
{
//////////////////////////////
// 1. super init first
if ( !CCLayer::init() )
{
return false;
}
//static const char* musicName = MUSIC_BG;
//CocosDenshion::SimpleAudioEngine::sharedEngine()->playBackgroundMusic(musicName, true);
UILayer *m_pUiLayer = UILayer::create();
m_pUiLayer->scheduleUpdate();
UIWidget *m_pWidget = dynamic_cast<Layout*>(CCUIHELPER->createWidgetFromJsonFile("Ditix_1.json"));
m_pUiLayer->addWidget(m_pWidget);
UIButton *btnStart = dynamic_cast<UIButton*>(m_pUiLayer->getWidgetByName("btnStart"));
txtNickname = dynamic_cast<UITextField*>(m_pUiLayer->getWidgetByName("txtNickname"));
btnStart->addPushDownEvent(btnStart, coco_pushselector(LoginScene::login));
this->addChild(m_pUiLayer);
return true;
}
void LoginScene::onEnter()
{
CCLayer::onEnter();
CCLOG(“Login onEnter”);
CCDirector::sharedDirector()->getScheduler()->scheduleSelector(schedule_selector(LoginScene::intoLoddy), this, 0, false);
}
void LoginScene::intoLoddy(){
if(isLogin){
isLogin = false;
CCLOG(“isLogin is true”);
CCDirector::sharedDirector()->getScheduler()->pauseTarget(this);
CCScene *lobbyScene = CCScene::create();
GameLobby *layer = new GameLobby();
layer->setClient(pomelo_client);
CCLog(" request client.state:%i", pomelo_client->state);
layer->setSessionID(sessionID);
layer->init();
lobbyScene->addChild(layer);
CCDirector::sharedDirector()->replaceScene(lobbyScene);
}
}
// send a request
void LoginScene::login(CCObject* obj,TouchEventType tType) {
sessionID = txtNickname->getStringValue();
const char *ip = DI_SERVER_ENTRY_IP;
int port = DI_SERVER_ENTRY_PORT;
pomelo_client = pc_client_new();
CCLog(" login client.state:%i", pomelo_client->state);
struct sockaddr_in address;
memset(&address, 0, sizeof(struct sockaddr_in));
address.sin_family = AF_INET;
address.sin_port = htons(port);
address.sin_addr.s_addr = inet_addr(ip);
// try to connect to server.
if(pc_client_connect(pomelo_client, &address)) {
CCLOG("fail to connect server.\n");
pc_client_destroy(pomelo_client);
return ;
}
const char *route = "connector.entryHandler.login";
json_t *msg = json_object();
json_t *str = json_string(sessionID);
json_object_set(msg, "uid", str);
// decref for json object
json_decref(str);
pc_request_t *request = pc_request_new();
void (*on_requst_login_cb)(pc_request_t *req, int status, json_t *resp) = &LoginScene::requstLoginCallback;
pc_request(pomelo_client, request, route, msg, on_requst_login_cb);
CCLog(" login client.state:%i", pomelo_client->state);
// main thread has nothing to do and wait until child thread return.
//pc_client_join(client);
// release the client
//pc_client_destroy(client);
//pc_client_stop(pc_client);
}
void LoginScene::requstLoginCallback(pc_request_t *req, int status, json_t *resp){
if(status == -1) {
CCLOG(“Fail to send request to server.\n”);
} else if(status == 0) {
char *json_str = json_dumps(resp, 0);
CCLOG(“server response: %s \n”, json_str);
isLogin = true;
CCLog(" login client.state:%i", req->client->state);
//pc_request_destroy(req);
//pc_client_t *pc_client = req->client;
//pc_client_stop(pc_client);
}
}
void LoginScene::menuCloseCallback(CCObject* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT) || (CC_TARGET_PLATFORM == CC_PLATFORM_WP8)
CCMessageBox(“You pressed the close button. Windows Store Apps do not implement a close button.”,“Alert”);
#else
CCDirector::sharedDirector()->end();
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
exit(0);
#endif
#endif
}
pomelo_client = pc_client_new(); //这个才是关键的初始化
我模拟了一下，结果必须是null的。（当然咱们new_client函数里面的不太一样就是了）
init(){
...
pomelo_client = new_client();
CCLOG("pomelo_client: %x, %d.", pomelo_client, *pomelo_client);
setClient(pomelo_client);
}
int* QTest::new_client()
{
int a = 132;
return &a;
}
void QTest::setClient(int* client)
{
CCLOG("client: %x, %d.", client, *client);
}
版主大人，为什么会出现这种情况呢？不理解啊。。。明明一开始已经初始化了（pomelo_client = pc_client_new();），为什么之后访问的时候丢失了？
有什么办法能解决吗？
pc_client_new(); //这个函数是怎么实现的？
你看看里面的实现。
像这种：
int* QTest::new_client()
{
int a = 132;
return &a;
}
```
肯定是会报错的。
因为里面是一个局部变量。
---
解决的方法，就是这里不要用局部变量。但没看到你的 pc_client_new（）这个函数是怎么实现的。不好下结论。
是不是你的LoginScene::login 没在 LoginScene::intoLoddy()之前运行呢