使用cocos2d-x 3.2下载图片资源小例子

cocos2d-x（ios）下载资源可以使用以下两种方式：

第一种使用libcurl下载图片

使用这种方法需要注意的是，我们需要引入libcurl.a这个库，同时配置对应的库目录和头文件目录具体方法是：

1 导入需要的.a静态数据库

静态库的位置是在

2 导入上图所对应的头文件，头文件的路径是cocos2d根目录/external/curl/include/ios/curl

导入方式在curl文件夹上右键加入新的文件，选择对应的文件夹......

3 配置头文件和库的目录

头文件目录：

库目录：

下载图片的代码：

.h文件

//
//  CurlDemo.h
//  LSWGameIOS
//
//  Created by lsw on 14-12-16.
//
//

#ifndef __LSWGameIOS__CurlDemo__
#define __LSWGameIOS__CurlDemo__

#include <stdio.h>
#include "cocos2d.h"

class CurlDemo : public cocos2d::Layer {
public:
    virtual bool init();
    static cocos2d::Scene* createScene();
    CREATE_FUNC(CurlDemo);
private:
    void downLoadPic();
    static size_t pWriteCallBack(void *pData, size_t n, size_t nDataSize, FILE *stream);
    static int downloadeProgress(void *clienttp, double fDownLoadTotal,double fDownLoaded,double fUpTotal,double fUpLoaded);
};

#endif /* defined(__LSWGameIOS__CurlDemo__) */

.cpp文件

//
//  CurlDemo.cpp
//  LSWGameIOS
//
//  Created by lsw on 14-12-16.
//
//

#include "CurlDemo.h"
#include "curl.h"

USING_NS_CC;

bool CurlDemo::init() {
    if (!Layer::init()) {
        return false;
    }
    
    CURLcode nResCode;
    CURL *pCurl = curl_easy_init();
    if (pCurl != nullptr) {
        auto fileName = FileUtils::getInstance()->getWritablePath() +"ceshi.jpg";
        FILE *pFile = fopen(fileName.c_str(), "wb+");
        CCLOG("filename = %s", fileName.c_str());
        curl_easy_setopt(pCurl, CURLOPT_URL, "http://ww1.sinaimg.cn/large/7f32a2c8jw1e8lyw03zpbj20c8d1ynpd.jpg");
        if (pFile != nullptr) {
            curl_easy_setopt(pCurl, CURLOPT_FILE, pFile); //设置文件指针
        }
        curl_easy_setopt(pCurl, CURLOPT_WRITEFUNCTION, pWriteCallBack); //回调方法
        curl_easy_setopt(pCurl, CURLOPT_VERBOSE, true);
        curl_easy_setopt(pCurl, CURLOPT_TIMEOUT, 60); //超时时间
        curl_easy_setopt(pCurl, CURLOPT_NOPROGRESS, 0L);
        curl_easy_setopt(pCurl, CURLOPT_PROGRESSFUNCTION, downloadeProgress);//下载进度
        nResCode = curl_easy_perform(pCurl);
        curl_easy_cleanup(pCurl);
        fclose(pFile);
        if (nResCode == CURLE_OK) {
            CCLOG("download success");
        } else {
            CCLOG("code : %d", nResCode);
        }
    }
    
    return true;
}

Scene *CurlDemo::createScene() {
    auto scene = Scene::create();
    auto layer = CurlDemo::create();
    scene->addChild(layer);
    return scene;
}


size_t CurlDemo::pWriteCallBack(void *pData, size_t n, size_t nDataSize, FILE *stream) {
    size_t nWriten = fwrite(pData, n, nDataSize, (FILE *)stream);
    return nWriten;
}

int CurlDemo::downloadeProgress(void *clienttp, double fDownLoadTotal, double fDownLoaded, double fUpTotal, double fUpLoaded) {
    if (fDownLoaded >= 0 && fDownLoadTotal != 0) {
        CCLOG(">>>>>>>%0.2f%%
", 100 * (fDownLoaded / fDownLoadTotal));
    }
    
    return 0;
}

第二种方式，使用HttpRequest中get方式下载图片

这种方式最大优点就是使用简单，使用cocos2d-x自己封装好的类和方法，设置及其简单。

.cpp文件

void HttpRequestDemo::downloadPicture() {
    HttpRequest *request = new HttpRequest();
    request->setRequestType(HttpRequest::Type::GET);
    request->setTag("downLoad tag 1");
    request->setUrl("http://img12.3lian.com/gaoqing02/06/56/13.jpg");
    request->setResponseCallback(CC_CALLBACK_2(HttpRequestDemo::onDownloadComplete, this));
    HttpClient::getInstance()->sendImmediate(request);
    request->release();
}

void HttpRequestDemo::onDownloadComplete(HttpClient *sender, HttpResponse *response) {
    if (!response) {
        return;
    }
    
    if (!response->isSucceed()) {
        CCLOG("error %s", response->getErrorBuffer());
        return;
    }
    
    std::vector<char> *buffData = response->getResponseData();
    char *buff = (char *)malloc(buffData->size());
    std::copy(buffData->begin(), buffData->end(), buff);
    auto fileName = FileUtils::getInstance()->getWritablePath() +"ceshi.jpg";
    FILE *fp = fopen(fileName.c_str(), "wb+");
    fwrite(buff, 1, buffData->size(), fp);
    fclose(fp);
}

参考文章：

http://blog.csdn.net/yirancpp/article/details/19123815

http://blog.csdn.net/yirancpp/article/details/19122921