flutter - 通过添加两个不同的列表生成第三个列表

Question

我有两个清单

List A have 3 items
List A={[name: abc, desc: abcd, img: httpsURL1],
       [name: xyz, desc: wxyz, img: httpsURL2],
       [name: def, desc: sahdw, img: httpsURL3]}

List B has only one item and name argument is same in both
List B={[name: abc, progress: 0.75]},

现在我想生成如下第三个列表：

List C = {[name: abc, desc: abcd, img: httpsURL1, progress:0.75],
       [name: xyz, desc: wxyz, img: httpsURL2, progress: 0],
       [name: def, desc: sahdw, img: httpsURL3, progress: 0]}

在 Dart 中可以吗？

标签： flutterdart

Answer 1

我在这里做了一个假设，即第一个列表将始终包含所有元素。否则，这应该是您提供的输入的示例，并提供您期望的输出。

在 DartPad 中查看此示例： https ://dartpad.dev/3cf607d4d0284702319e562099e19b1e

void main() {
  var aList = [
    new ClassA("abc", "abcd", "httpsURL1"),
    new ClassA("xyz", "wxyz", "httpsURL2"),
    new ClassA("def", "sahdw", "httpsURL3")
  ];

  var bList = [
    new ClassB("abc", 0.75),
  ];

  var result = aList
      .map((a) => bList.any((b) => b.name == a.name)
          ? new ClassC(a.name, a.desc, a.img,
              bList.firstWhere((b) => a.name == b.name).progress)
          : new ClassC(a.name, a.desc, a.img, 0))
      .toList();

  print(result);
}

class ClassA {
  String name;
  String desc;
  String img;

  ClassA(this.name, this.desc, this.img);
}

class ClassB {
  String name;
  double progress;

  ClassB(this.name, this.progress);
}

class ClassC {
  String name;
  String desc;
  String img;
  double progress;

  ClassC(this.name, this.desc, this.img, this.progress);
}