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flutter - 如何在颤动的Listview中显示字符串列表

问题描述

我有字符串列表。我需要在界面中将它们显示为列表。

List<String> spec_list = urlremoved.split(", ");

我只需要向他们展示。但它不起作用。请帮助遇到或找出错误。我附上了下面的代码

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';



class ItemView extends StatefulWidget {
  final String docID123;

  const ItemView({ this.docID123}) ;

  @override
  _ItemViewState createState() => _ItemViewState();
}
String name123;
class _ItemViewState extends State<ItemView> {
  @override
  //String docuID = Widget.documentid;
  
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Item Data'),
      ),
      body: ListView(
        children: <Widget>[
          Text(widget.docID123),
          getItems(),
          
        ],
      ),
    );
  }
}


Widget getItems(){
    return StreamBuilder(
      //1597917013710
      stream: Firestore.instance.collection('ads').document('1597917013710').snapshots(),
      builder: (context, snapshot){
        if (!snapshot.hasData) {
          //snapshot.data.toString();
          return new Text("Loading");
        }
        DocumentSnapshot dd = snapshot.data; 

        var userDocument = snapshot.data;
        //String myname = dd.data.toString();
        int len = dd.data.length;
        
        String jsonString = dd.data.toString();
        String start = "[";
        String end = "]";
        final startIndex = jsonString.indexOf(start);
        final endIndex = jsonString.indexOf(end, startIndex + start.length);
        String next = jsonString.substring(startIndex + start.length, endIndex);
        String imagelinkRemoved = jsonString.replaceAll(next, "");
        String urlremoved = imagelinkRemoved.replaceAll("urls: [], ", "").replaceAll("{", "").replaceAll("}", "");

        List<String> spec_list = urlremoved.split(", ");
        int speclistlen = spec_list.length;
        
        return Container(
      child: Column(
        children: <Widget>[
          Text(spec_list[0]),
          ListView.builder(
            itemCount: speclistlen,
            itemBuilder: (context,index){
              return Text(spec_list[index]);
            },
          )
        ],
      ),
    );
      }
    );
}


Future getCatagory() async {
      var firestone = Firestore.instance;

      QuerySnapshot alldata = await firestone.collection("catagory_names/Vehicles").getDocuments();
      for(int i=0;i<alldata.documents.length;i++){
                        DocumentSnapshot snap = alldata.documents[i];
                        
                      }

      return  Text('12345');

    }

标签： flutterlistviewdartbuilder

解决方案

仅当您speclistlen为空时才会发生这种情况在执行上述代码时，您似乎遇到了未绑定的高度异常。为了避免shrinkWrap: true,在里面使用Listview.Builder

Widget getItems() {
  return StreamBuilder(
      //1597917013710
      stream: Stream.periodic(Duration(seconds: 2)),
      builder: (context, snapshot) {
        String urlremoved = "I, am, jits555";

        List<String> spec_list = urlremoved.split(", ");
        int speclistlen = spec_list.length;

        return Container(
          child: Column(
            children: <Widget>[
              Text(spec_list[0]),
              ListView.builder(
                shrinkWrap: true,
                itemCount: speclistlen,
                itemBuilder: (context, index) {
                  return Text(spec_list[index]);
                },
              )
            ],
          ),
        );
      });
}

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