將長字串決議為lat&longsFlutter

我從 Json 中的 API 呼叫中收到StringLats & Longs

"lineStrings": [
        "[[[-0.301457,51.515017],[-0.288265,51.51014],[-0.280462,51.503057],[-0.267972,51.494627],[-0.254555,51.495148],[-0.245704,51.494917],[-0.235881,51.494122],[-0.22362,51.4923],[-0.213427,51.490311],[-0.206636,51.490459],[-0.193378,51.492063],[-0.182658,51.494316],[-0.174138,51.494094],[-0.156377,51.49227],[-0.143102,51.496359],[-0.133608,51.499544],[-0.124861,51.50132],[-0.122666,51.507058],[-0.11426,51.511006],[-0.103659,51.511581],[-0.094009,51.512117],[-0.090432,51.51151],[-0.085969,51.5107],[-0.076546,51.509971],[-0.072384,51.515037],[-0.059971,51.519518],[-0.046596,51.521858],[-0.03364,51.525122],[-0.025128,51.52694],[-0.011538,51.524839],[0.005055,51.528136],[0.017451,51.531341],[0.035263,51.53534],[0.051186,51.538948],[0.081053,51.539321],[0.10153,51.538372],[0.127016,51.540331],[0.147527,51.541639],[0.166017,51.544096],[0.19864,51.549775],[0.219116,51.554093],[0.235809,51.55856],[0.250882,51.559063]]]"]

與我習慣的呼叫不同，它們不是作為我可以迭代的單獨的緯度和經度值來的，它作為一個長字串塊回傳。

我可能不正確，但我不相信我可以決議它，因為沒有lat&long類可以迭代，lineStrings這只是一個長塊。我要決議的 Quicktype.io 類將我帶到.linestrings迭代時

我想將它們分成坐標對，我可以從每個坐標對中獲取緯度和經度。

我試過```splitting```` 但是由于雙打和對之間的逗號我無法讓它作業。我也嘗試洗掉特殊字符，但無法保持格式化。

歡迎任何建議。

最終目標是能夠執行以下操作

for (var x in coordinates){
GeoCoordinates y = GeoCoordinates(x.latitude, x.longitude);
}

謝謝

uj5u.com熱心網友回復：

您必須進行一些手動拆分：

void main() {
  '[[[-0.301457,51.515017],[-0.288265,51.51014],[-0.280462,51.503057]]]'
      .split('],[')
      .forEach((p) => print(p.replaceAll('[', '').replaceAll(']', '')));
}

印刷：

-0.301457,51.515017
-0.288265,51.51014
-0.280462,51.503057

您可以進一步拆分,并決議為一對雙打。

或者你可以添加一個LatLong類來保存這對：

void main() {
  final latLongs =
      '[[[-0.301457,51.515017],[-0.288265,51.51014],[-0.280462,51.503057]]]'
          .split('],[')
          .map((p) => LatLong.fromString(
                p.replaceAll('[', '').replaceAll(']', ''),
              ));

  print(latLongs);
}

class LatLong {
  LatLong(this.lat, this.long);

  factory LatLong.fromString(String pair) {
    final parts = pair.split(',');
    return LatLong(double.parse(parts[0]), double.parse(parts[1]));
  }

  double lat;
  double long;
}

uj5u.com熱心網友回復：

var json = {"lineStrings": [
                    "[[[-0.301457,51.515017],[-0.288265,51.51014],[-0.280462,51.503057],[-0.267972,51.494627],[-0.254555,51.495148],[-0.245704,51.494917],[-0.235881,51.494122],[-0.22362,51.4923],[-0.213427,51.490311],[-0.206636,51.490459],[-0.193378,51.492063],[-0.182658,51.494316],[-0.174138,51.494094],[-0.156377,51.49227],[-0.143102,51.496359],[-0.133608,51.499544],[-0.124861,51.50132],[-0.122666,51.507058],[-0.11426,51.511006],[-0.103659,51.511581],[-0.094009,51.512117],[-0.090432,51.51151],[-0.085969,51.5107],[-0.076546,51.509971],[-0.072384,51.515037],[-0.059971,51.519518],[-0.046596,51.521858],[-0.03364,51.525122],[-0.025128,51.52694],[-0.011538,51.524839],[0.005055,51.528136],[0.017451,51.531341],[0.035263,51.53534],[0.051186,51.538948],[0.081053,51.539321],[0.10153,51.538372],[0.127016,51.540331],[0.147527,51.541639],[0.166017,51.544096],[0.19864,51.549775],[0.219116,51.554093],[0.235809,51.55856],[0.250882,51.559063]]]"
                  ]
                };


                List<dynamic> jsonList = json["lineStrings"]!
                    .first
                    .replaceAll("[", "")
                    .replaceAll("]", "")
                    .split(",");


                List<Coordinates> result = [];
                for (var i = 0; i < jsonList.length / 2; i  ) {
                  result.add(Coordinates(
                      lat: double.parse(jsonList[i]),
                      long: double.parse(jsonList[i   1])));
                }


                result.forEach((element) {
                  print("Lat"   element.lat.toString());
                  print("Long"   element.long.toString());
                  print("*************************");
                });

class Coordinates {
      double lat;
      double long;

  Coordinates({
    required this.lat,
    required this.long,
 });
 }

顫振：Lat-0.301457

顫振：Long51.515017

顫振：**************************

顫振：Lat51.515017

顫振：Long-0.288265

顫振：**************************

顫振：Lat-0.288265

顫振：Long51.51014

顫振：**************************

標籤：json 扑 镖

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