解析天气预报JSON数据

JSON字符串

const

json2 = '{' + #13#10 +

'"error":0,' + #13#10 +

'"status":"success",'+ #13#10 +

'"date":"2014-03-04",'+ #13#10 +

'"results":'+ #13#10 +

'[{"currentCity":"成都",'+ #13#10 +

' "weather_data":['+ #13#10 +

'{'+ #13#10 +

'"date":"周二(今天, 实时：12℃)",'+ #13#10 +

'"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/duoyun.png",'+ #13#10 +

'"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/duoyun.png",'+ #13#10 +

'"weather":"多云",'+ #13#10 +

'"wind":"北风微风",'+ #13#10 +

'"temperature":"15 ~ 6℃"'+ #13#10 +

'},'+ #13#10 +

'{'+ #13#10 +

'"date":"周三",'+ #13#10 +

'"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/yin.png",'+ #13#10 +

'"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/xiaoyu.png",'+ #13#10 +

'"weather":"阴转小雨",'+ #13#10 +

'"wind":"北风微风",'+ #13#10 +

'"temperature":"14 ~ 7℃"'+ #13#10 +

'},'+ #13#10 +

'{'+ #13#10 +

'"date":"周四",'+ #13#10 +

'"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/xiaoyu.png",'+ #13#10 +

'"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/xiaoyu.png",'+ #13#10 +

'"weather":"小雨",'+ #13#10 +

'"wind":"北风微风",'+ #13#10 +

'"temperature":"12 ~ 7℃"'+ #13#10 +

'},'+ #13#10 +

'{'+ #13#10 +

'"date":"周五",'+ #13#10 +

'"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/xiaoyu.png",'+ #13#10 +

'"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/xiaoyu.png",'+ #13#10 +

'"weather":"小雨",'+ #13#10 +

'"wind":"南风微风",'+ #13#10 +

'"temperature":"9 ~ 6℃"'+ #13#10 +

'}'+ #13#10 +

']'+ #13#10 +

'}'+ #13#10 +

']}';

1）MORMOT SDK解析JSON：

uses

SynCommons;

procedure TForm1.Button5Click(Sender: TObject);

var

doc: variant;

json: RawUTF8;

count, i: Integer;

begin

doc := _JsonFast(JSON2); // json还原为variant

Memo1.Clear;

Memo1.Lines.Add(doc.error); // 0

Memo1.Lines.Add(doc.status); // success

Memo1.Lines.Add(doc.date); // 2014-03-04

Memo1.Lines.Add(doc.results._(0).currentCity); // 成都

count := doc.results._(0).weather_data._count; // 取JSON数组 长度

for i := 0 to count - 1 do // 遍历JSON数组

Memo1.Lines.Add(doc.results._(0).weather_data._(i).weather);

end;

2）DELPHI官方库解析JSON：

 procedure TfjsonDemo.Button1Click(Sender: TObject);

var

  root, results: TJSONObject;

  LItem: TJSONValue;

  weather: TJSONArray;

  StrJson: string;

  result: string;

  i: Integer;

begin

  StrJson := Memo1.Text;

  root := TJSONObject.ParseJSONValue(TEncoding.UTF8.GetBytes(StrJson), 0) as TJSONObject;

  results := (root.GetValue('results') as TJSONArray).Get(0) as TJSONObject;

  weather := results.GetValue('weather_data') as TJSONArray;

  for i := 0 to weather.size - 1 do //应该是4条记录

  begin

    LItem := (weather.Get(i) as TJSONObject).GetValue('weather'); //得到weather的值

    result := result + '|'+ LItem.Value;

  end;

  Memo2.Text := result;

end;