C++提取文件中信息的方法

對于文件比較復雜的時候，為了獲取文件中的信息，需要一些比較特殊的函數，比如，getline()、replace（）、atoi,atof等

我們提供的服務有：網站建設、成都網站設計、微信公眾號開發、網站優化、網站認證、扎賚諾爾ssl等。為1000多家企事業單位解決了網站和推廣的問題。提供周到的售前咨詢和貼心的售后服務，是有科學管理、有技術的扎賚諾爾網站制作公司

例子一，讀取以下文件中的數據，并保存進一個類里面。

首先，類的定義如下，感覺是struct，但是按照struct的處理，我這段代碼出錯了，不知道什么問題，暫時po出來吧，有空看看。

struct ImageLabel{
  std::string imagePath;//save圖片路徑名
  int faceBox[4];//輸入點集的最外層包絡矩形rect四個參數
  int landmarkPos[2*LandmarkPointsNum];//輸入點集

private:
  friend class cereal::access;
  /**
   * Serialises this class using cereal.
   *
   * @param[in] ar The archive to serialise to (or to serialise from).
   */
  template<class Archive>
  void serialize(Archive& ar)
  {
    ar(imagePath, faceBox, landmarkPos);
  }
};

然后讀入一系列如下文件，每個文件的數據保存格式相同，因此定義了一個vector，來順序存儲每一個文件對應的類

文件如下：*.pts文件

version: 1
n_points: 68
{
446.000 91.000
449.459 119.344
450.957 150.614
460.552 176.986
471.486 202.157
488.087 226.842
506.016 246.438
524.662 263.865
553.315 271.435
578.732 266.260
599.361 248.966
615.947 220.651
627.439 197.999
635.375 179.064
642.063 156.371
647.302 124.753
646.518 92.944
470.271 117.870
486.218 109.415
503.097 114.454
519.714 120.090
533.680 127.609
571.937 123.590
585.702 117.155
602.344 109.070
620.077 103.951
633.964 111.236
554.931 145.072
554.589 161.106
554.658 177.570
554.777 194.295
532.717 197.930
543.637 202.841
555.652 205.483
565.441 202.069
576.368 197.061
487.474 136.436
499.184 132.337
513.781 133.589
527.594 143.047
513.422 144.769
499.117 144.737
579.876 140.815
590.901 130.008
605.648 128.376
618.343 132.671
606.771 140.525
593.466 141.419
519.040 229.040
536.292 221.978
}

所有pts文件名都保存在一個TXT文件中，對應的圖像名也保存在一個TXT文件中，我們需要把圖片的文件路徑加文件名保存到類里面，為了處理方便我們用了replace函數，直接替換pts文件名的的后三位，得到新的文件名。

void readpic(std::vector<ImageLabel> &Imagelabels){
   cout<<"test readpic"<<endl;

   string filePath = "/Users/anitafang/Downloads/Datasets/300W/300w/01_Indoor/";
  //打開png圖片名存儲的TXT文件
  ifstream pngfile;
  pngfile.open("/Users/anitafang/Downloads/Datasets/300W/300w/01_Indoor/pnglist.txt");
    if(!pngfile.is_open()){
    cout<<"不能打開文件!"<<endl;
  }
  //ImageLabel* mImageLabel = NULL;//保存圖像信息的類
  string line;//讀取文件的每一行
  while(getline(pngfile,line)){
    //mImageLabel = new ImageLabel();
    ImageLabel mImageLabel;
    //mImageLabel->imagePath=filePath+line;//將文件全路徑保存在 mImageLabel->imagePath
    mImageLabel.imagePath=filePath+line;//將文件全路徑保存在 mImageLabel->imagePath
    cout<<line<<endl;
    //得到pts文件路徑
    string ress="pts";
    string ptss=filePath+line.replace(11,3,ress);
    cout<<line.replace(11,3,ress)<<endl;
    cout<<ptss<<endl;
    //讀取pts文件里面的數據
    std::ifstream LabelsFile(ptss, std::ios::in);
    if(!LabelsFile.is_open())
      return;
   //開始讀取pts文件內容
    int index=0;
    vector<Point2f> vp2f;
    char line11[1024]={0};//存放每行數據
    //將文件逐行讀取到string linestr中，然后對行的內容進行判斷
    while(LabelsFile.getline(line11, sizeof(line11))){
      //從第四行開始把數據寫進landmark數組中
      if((index>=3)&&(index<139)){
        string x = "";
        string y = "";
        std::stringstream word(line11);
        word >> x;
        word >> y;
        cout<<atof(x.c_str())<<" "<<atof(y.c_str())<<endl;
        mImageLabel.landmarkPos[index-3] =atof(x.c_str());
        mImageLabel.landmarkPos[index+LandmarkPointsNum-3] =atof(y.c_str());
        
        vp2f.push_back(Point2f(mImageLabel.landmarkPos[index-3],mImageLabel.landmarkPos[index+LandmarkPointsNum-3]));
        cout<<"x:"<<mImageLabel.landmarkPos[index-3]<<" y:"<<mImageLabel.landmarkPos[index+LandmarkPointsNum-3]<<endl;
        
      }
      index++;
      
    }
    
  
  Rect rect = boundingRect(vp2f);

  //根據得到的矩形 輸入到facebox中
  mImageLabel.faceBox[0] = rect.x;
  mImageLabel.faceBox[1] = rect.y;
  mImageLabel.faceBox[2] = rect.width;
  mImageLabel.faceBox[3] = rect.height;
  
  cout<<"facebox"<<mImageLabel.faceBox[0]<<mImageLabel.faceBox[1]<<mImageLabel.faceBox[2]<<mImageLabel.faceBox[3]<<endl;
    
     // close file
  LabelsFile.close();
    //free the object
  Imagelabels.push_back(mImageLabel);

  //mImageLabel == NULL;
    
  }
}

其中，因為GetLine讀出來的數據是string類型，因此需要將數據轉成int型，看到pts文件中數據是都是float型，因此先要將string轉成float，用的是atof函數。

另外如果把 Imagelabels 當做類來處理只需要，最開始，ImageLabel mImageLabel;后面直接push_back，不需要delete。所有的引用都變成：mImageLabel.faceBox，不能用mImageLabel->landmarkPos。

另外一個升級的例子，處理起來很復雜，這里把ImageLabel當做一個struct來處理，這樣需要new，也需要delete,引用的時候也是用的->，這個需要注意。

文件是：labels_ibug_300W.xml

稍微看一部分，了解下它的構成。

<?xml version='1.0' encoding='ISO-8859-1'?>
<?xml-stylesheet type='text/xsl' href='image_metadata_stylesheet.xsl'?>
<dataset>
<name>iBUG face point dataset - All images</name>
<comment>This folder contains data downloaded from:
/upload/otherpic57/110838.jpg.

Finally, note that the bounding boxes are from dlib's default face detector. For the
faces the detector failed to detect, we guessed at what the bounding box would have been
had the detector found it and used that.</comment>
<images>
 <image file='afw/1051618982_1.jpg'>
  <box top='206' left='469' width='216' height='216'>
   <part name='00' x='482' y='267'/>
   <part name='01' x='483' y='298'/>
   <part name='02' x='487' y='329'/>
   <part name='03' x='491' y='358'/>
   <part name='04' x='503' y='386'/>
   <part name='05' x='523' y='409'/>
   <part name='06' x='543' y='428'/>
   <part name='07' x='565' y='442'/>
   <part name='08' x='591' y='447'/>
   <part name='09' x='620' y='443'/>
   <part name='10' x='647' y='429'/>
   <part name='11' x='671' y='409'/>
   <part name='12' x='688' y='385'/>
   <part name='13' x='699' y='359'/>
   <part name='14' x='704' y='332'/>
   <part name='15' x='707' y='305'/>
   <part name='16' x='708' y='277'/>
   <part name='17' x='502' y='250'/>
   <part name='18' x='518' y='237'/>
   <part name='19' x='537' y='234'/>
   <part name='20' x='557' y='236'/>
   <part name='21' x='575' y='243'/>
   <part name='22' x='619' y='243'/>
   <part name='23' x='639' y='237'/>
   <part name='24' x='659' y='234'/>
   <part name='25' x='679' y='238'/>
   <part name='26' x='693' y='250'/>
   <part name='27' x='596' y='268'/>
   <part name='28' x='595' y='287'/>
   <part name='29' x='594' y='305'/>
   <part name='30' x='593' y='324'/>
   <part name='31' x='570' y='336'/>
   <part name='32' x='581' y='338'/>
   <part name='33' x='593' y='342'/>
   <part name='34' x='605' y='338'/>
   <part name='35' x='615' y='336'/>
   <part name='36' x='523' y='272'/>
   <part name='37' x='536' y='263'/>
   <part name='38' x='551' y='263'/>
   <part name='39' x='564' y='277'/>
   <part name='40' x='550' y='277'/>
   <part name='41' x='535' y='276'/>
   <part name='42' x='626' y='279'/>
   <part name='43' x='642' y='265'/>
   <part name='44' x='657' y='267'/>
   <part name='45' x='670' y='276'/>
   <part name='46' x='658' y='280'/>
   <part name='47' x='642' y='279'/>
   <part name='48' x='544' y='364'/>
   <part name='49' x='565' y='360'/>
   <part name='50' x='580' y='357'/>
   <part name='51' x='591' y='360'/>
   <part name='52' x='603' y='358'/>
   <part name='53' x='621' y='361'/>
   <part name='54' x='641' y='366'/>
   <part name='55' x='621' y='382'/>
   <part name='56' x='603' y='385'/>
   <part name='57' x='590' y='384'/>
   <part name='58' x='579' y='383'/>
   <part name='59' x='563' y='378'/>
   <part name='60' x='552' y='366'/>
   <part name='61' x='580' y='370'/>
   <part name='62' x='591' y='370'/>
   <part name='63' x='603' y='371'/>
   <part name='64' x='634' y='369'/>
   <part name='65' x='603' y='371'/>
   <part name='66' x='591' y='370'/>
   <part name='67' x='580' y='370'/>
  </box>
 </image>
 <image file='afw/111076519_1.jpg'>
  <box top='724' left='1122' width='150' height='150'>
   <part name='00' x='1126' y='765'/>
   <part name='01' x='1123' y='784'/>
   <part name='02' x='1123' y='804'/>
   <part name='03' x='1124' y='822'/>
   <part name='04' x='1131' y='839'/>
   <part name='05' x='1142' y='853'/>
   <part name='06' x='1157' y='865'/>
   <part name='07' x='1172' y='874'/>
   <part name='08' x='1190' y='878'/>
   <part name='09' x='1208' y='878'/>
   <part name='10' x='1225' y='873'/>
   <part name='11' x='1238' y='862'/>
   <part name='12' x='1249' y='846'/>
   <part name='13' x='1256' y='829'/>
   <part name='14' x='1261' y='810'/>
   <part name='15' x='1263' y='792'/>
   <part name='16' x='1264' y='774'/>
   <part name='17' x='1148' y='749'/>
   <part name='18' x='1160' y='745'/>
   <part name='19' x='1171' y='744'/>
   <part name='20' x='1183' y='748'/>
   <part name='21' x='1194' y='753'/>
   <part name='22' x='1227' y='756'/>
   <part name='23' x='1236' y='753'/>
   <part name='24' x='1244' y='753'/>
   <part name='25' x='1251' y='754'/>
   <part name='26' x='1256' y='759'/>
   <part name='27' x='1210' y='769'/>
   <part name='28' x='1210' y='779'/>
   <part name='29' x='1210' y='790'/>
   <part name='30' x='1209' y='800'/>
   <part name='31' x='1187' y='808'/>
   <part name='32' x='1196' y='811'/>
   <part name='33' x='1205' y='814'/>
   <part name='34' x='1212' y='813'/>
   <part name='35' x='1218' y='812'/>
   <part name='36' x='1159' y='766'/>
   <part name='37' x='1167' y='763'/>
   <part name='38' x='1176' y='764'/>
   <part name='39' x='1183' y='770'/>
   <part name='40' x='1175' y='770'/>
   <part name='41' x='1166' y='769'/>
   <part name='42' x='1225' y='776'/>
   <part name='43' x='1235' y='773'/>
   <part name='44' x='1243' y='774'/>
   <part name='45' x='1248' y='777'/>
   <part name='46' x='1241' y='779'/>
   <part name='47' x='1233' y='779'/>
   <part name='48' x='1160' y='825'/>
   <part name='49' x='1176' y='820'/>
   <part name='50' x='1190' y='822'/>
   <part name='51' x='1199' y='824'/>
   <part name='52' x='1209' y='825'/>
   <part name='53' x='1221' y='827'/>
   <part name='54' x='1229' y='833'/>
   <part name='55' x='1218' y='847'/>
   <part name='56' x='1205' y='852'/>
   <part name='57' x='1194' y='851'/>
   <part name='58' x='1184' y='849'/>
   <part name='59' x='1171' y='840'/>
   <part name='60' x='1165' y='827'/>
   <part name='61' x='1189' y='828'/>
   <part name='62' x='1199' y='830'/>
   <part name='63' x='1208' y='831'/>
   <part name='64' x='1225' y='834'/>
   <part name='65' x='1206' y='844'/>
   <part name='66' x='1196' y='844'/>
   <part name='67' x='1186' y='841'/>
  </box>
 </image>
 <image file='afw/111076519_2.jpg'>
  <box top='590' left='1028' width='180' height='180'>
   <part name='00' x='1050' y='620'/>
   <part name='01' x='1046' y='641'/>
   <part name='02' x='1040' y='663'/>

可以找到一些規律，按照這些規律來得到我們需要的數據，直接上代碼：

void ReadLabelsFromFile(std::vector<ImageLabel> &Imagelabels, std::string Path = "labels_ibug_300W.xml"){
  std::string ParentPath(trainFilePath);
  std::ifstream LabelsFile(ParentPath+Path, std::ios::in);
  if(!LabelsFile.is_open())
    return;
  std::string linestr;
  while(std::getline(LabelsFile, linestr)){
    linestr = trim(linestr);
    linestr = replace(linestr, "</", "");
    linestr = replace(linestr, "/>", "");
    linestr = replace(linestr, "<", "");
    linestr = replace(linestr, ">", "");
    linestr = replace(linestr, "'", "");
 
    std::vector<std::string> strNodes = split(linestr, " ");
    static ImageLabel* mImageLabel = NULL;
    switch (strNodes.size()) {
    case 1:
      if(strNodes[0] == "image"){
        Imagelabels.push_back(*mImageLabel);
        delete mImageLabel;
      }
      break;
    case 2:
      if(strNodes[0] == "image"){
        mImageLabel = new ImageLabel();
        mImageLabel->imagePath = ParentPath + split(strNodes[1], "=")[1];
//        std::cout << mImageLabel->imagePath << std::endl;
//        cv::Mat Image = cv::imread(mImageLabel->imagePath);
//        cv::imshow("Image", Image);
//        cv::waitKey(0);
      }
      break;
    case 5:
      if(strNodes[0] == "box"){
        mImageLabel->faceBox[0] = atoi(split(strNodes[1], "=")[1].data());
        mImageLabel->faceBox[1] = atoi(split(strNodes[2], "=")[1].data());
        mImageLabel->faceBox[2] = atoi(split(strNodes[3], "=")[1].data());
        mImageLabel->faceBox[3] = atoi(split(strNodes[4], "=")[1].data());
      }
      break;
    case 4:
      if(strNodes[0] == "part"){
        int index = atoi(split(strNodes[1], "=")[1].data());
        mImageLabel->landmarkPos[index] = atoi(split(strNodes[2], "=")[1].data());
        mImageLabel->landmarkPos[index+LandmarkPointsNum] = atoi(split(strNodes[3], "=")[1].data());
      }
      break;
    default:
      break;
    }
  }
  LabelsFile.close();
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持創新互聯。

分享文章：C++提取文件中信息的方法
本文網址：http://www.yijiale78.com/article42/ghdhhc.html

成都網站建設公司_創新互聯，為您提供軟件開發、響應式網站、網站改版、面包屑導航、小程序開發、網站導航

聲明：本網站發布的內容（圖片、視頻和文字）以用戶投稿、用戶轉載內容為主，如果涉及侵權請盡快告知，我們將會在第一時間刪除。文章觀點不代表本網站立場，如需處理請聯系客服。電話：028-86922220；郵箱：631063699@qq.com。內容未經允許不得轉載，或轉載時需注明來源：創新互聯

猜你還喜歡下面的內容

99偷拍视频精品区一区二,口述久久久久久久久久久久,国产精品夫妇激情啪发布,成人永久免费网站在线观看,国产精品高清免费在线,青青草在线观看视频观看,久久久久久国产一区,天天婷婷久久18禁,日韩动漫av在线播放直播

C++提取文件中信息的方法