httpclient的简单运用。

delphi的httpclient库能够操作http和https链接。应该是XE以后新出的库。试了试用来抓网页还行。里面使用了HtmlParserEx库。只支持xe3以后的版本，看说明还能支持其他平台。该库使我们能够调用css选择器或xpath来取得我们需要的数据。

program 获取图片链接;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils,
  System.Net.HttpClient,
  HtmlParserEx in 'HtmlParserEx.pas';

const
  url:string='https://www.italika.mx/Modelos/Trabajo/';
var
    stext:string;
    LHtml:IHtmlElement;
    LList:IHtmlElementList;
begin
  try
    var http:THTTPClient:=THTTPClient.Create;
    http.UserAgent:='Mozilla/5.0';
    stext:=http.Get(url).ContentAsString();
    LHtml:=ParserHtml(stext);
    if LHtml <> nil then
    begin
      LList := LHtml.Find('li.display_tCell img');
      for LHtml in LList do
        Writeln('url:', lhtml.Attributes['src']);
    end;
    http.Free;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
    readln;
end.

　通过选择器处理后取得图片链接。效果如图：

得到图片链接可以尝试下载网络图。完整代码如下：

program 获取图片链接;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils,
  System.Net.HttpClient,Vcl.Imaging.pngimage,Vcl.Graphics,
  HtmlParserEx in 'HtmlParserEx.pas';

const
  url:string='https://www.italika.mx/Modelos/Trabajo/';
var
    stext:string;
    LHtml:IHtmlElement;
    LList:IHtmlElementList;
    pngImg:TpngImage;
    i:Cardinal;
begin
  try
    var http:THTTPClient:=THTTPClient.Create;
    pngImg:=TpngImage.Create;
    i:=0;
    http.UserAgent:='Mozilla/5.0';
    stext:=http.Get(url).ContentAsString();
    LHtml:=ParserHtml(stext);
    if LHtml <> nil then
    begin
      LList := LHtml.Find('li.display_tCell img');
      for LHtml in LList do
      begin
       inc(i);
       pngImg.LoadFromStream(http.Get(lhtml.Attributes['src']).ContentStream);
       pngImg.SaveToFile('C:\Users\FanXiaoLei\Desktop\vb6regfreecom\'+ inttostr(i)+'.png');

      end;
    end;
    pngImg.Free;
    http.Free;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
    readln;
end.

　网络图片下载到了本地：

 

 

HtmlParserEx库下载：https://files.cnblogs.com/files/FanXiaoLei/HtmlParserEx.zip