小编Par*_*eri的帖子

问题是我想在文本字段的值末尾添加“,00”在 iOS 设备中效果很好，但在 android 中光标移动到文本字段中值的起点。所以，我无法添加“,00”。

不知道如何从颤振中的云函数中获得响应。

我的云功能

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

exports.testDemo = functions.https.onRequest((request, response) => {
  return response.status(200).json({msg:"Hello from Firebase!"});
 });

我的颤振代码

///Getting an instance of the callable function:
    try {
      final HttpsCallable callable = CloudFunctions.instance.getHttpsCallable(
        functionName: 'testDemo',);

      ///Calling the function with parameters:
      dynamic resp = await callable.call();
      print("this is responce from firebase $resp");

    } on CloudFunctionsException catch (e) {
      print('caught firebase functions exception');
      print(e.code);
      print(e.message);
      print(e.details);
    } catch (e) {
      print('caught generic exception');
      print(e);
    }

颤振：捕获了 Firebase 函数异常颤振：内部颤振：响应缺少数据字段。颤振：空

我将google map小部件添加到具有边框半径的容器中，但google map角未圆化。

Container(
            height: 100,
            width: double.infinity,
            margin: EdgeInsets.only(left: 30, right: 30),
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(30),
              border: Border.all(
                style: BorderStyle.solid,
              ),
            ),
            child: GoogleMap(),)

如何在 flutter 中使用 where 和 orderBy。

任何人都可以告诉我这些索引是如何工作的以及如何正确创建它们。

Query query = Firestore.instance
        .collection('clients')
        .where('sequenceStatus', isEqualTo: sequenceName)
        .orderBy('created', descending: true)
        .limit(20);

W/Firestore(19854)：(19.0.0) [Firestore]：侦听查询（其中sequenceStatus ==引用 order by -created, - name的客户端）失败：Status{code=FAILED_PRECONDITION，description=查询需要索引。您可以在此处创建它： https: //console.firebase.google.com/project/rigatoinfissitest/database/firestore/indexes ?create_composite =ClFwcm9qZWN0cy9yaWdhdG9pbmZpc3NpdGVzdC9kYXRhYmFzZXMvKGRlZmF1bHQpL2NvbGxlY3Rpb25Hcm91cHMvY2 xpZW50cy9pbmRleGVzL18QARoSCg5zZXF1ZW5jZVN0YXR1cxABGgsKB2NyZWF0ZWQQAhoMCghfX25hbWVfXxAC，原因=null}

在选项卡之间切换 initstate() 被多次调用。

我的标签栏中有 4 个标签 A、B、C 和 D。

情况（1）如果我像从选项卡 A 切换到选项卡 B 一样，它工作正常。

情况 (2) 但如果我要转到选项卡 A 到 C，则选项卡“B”的 initstate() 会调用两次

案例(1)结果

扑动：A

颤振：B

案例(2)的结果

扑动：A

颤振：B

颤振：C

颤振：B

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) …

想要找到 2 个点的中心并适合地图。当我在地图上查看时，我想适合所有屏幕。我准备好绘制路线，但它只适合 1 点。请帮我。这个类是用于颤振的地图视图。我尝试更多天找到插件和解决方案，但仍未找到。

 GoogleMap(
              mapType: MapType.normal,
              markers: _markers,
//              cameraTargetBounds: CameraTargetBounds(new LatLngBounds(
//                  northeast: LatLng(latFrom, logFrom),
//                  southwest: LatLng(latTo, logTo),
//              )),
//              minMaxZoomPreference: MinMaxZoomPreference(1, 15),
              mapToolbarEnabled: true,
              scrollGesturesEnabled: true,
              zoomGesturesEnabled: true,
              trafficEnabled: true,
              compassEnabled: true,
              indoorViewEnabled: true,
              rotateGesturesEnabled: true,
              tiltGesturesEnabled: true,
              myLocationButtonEnabled: true,
              myLocationEnabled: true,
              polylines: _polyline,
//              padding: EdgeInsets.all(20),
              initialCameraPosition:
                  CameraPosition(
                      target: LatLng(latFrom, logFrom),
                      zoom: 10,
                  ),
              onMapCreated: (GoogleMapController controller) {
                _controller.complete(controller);
              })

我想重新排序我的列表，但出现此错误。该小部件的所有子项都必须在可重新排序列表视图中拥有一个键

Widget list(list) {
    return Scrollbar(
      child: ReorderableListView(
          header: null,
          onReorder: _onReorder,
          padding: const EdgeInsets.symmetric(vertical: 8.0),
          children: <Widget>[
            ListView.builder(
              itemCount: list.length,
              shrinkWrap: true,
              itemBuilder: (contex, index) {
                return _singleToDoWidget(list[index], index);
              },
            )
          ]),
    );
}

我没有找到构造函数的任何示例CupertinoFullscreenDialogTransition

https://api.flutter.dev/flutter/cupertino/CupertinoFullscreenDialogTransition-class.html

我试图理解下面的代码，但我没有明白。

CupertinoFullscreenDialogTransition({
  Key key,
  @required Animation<double> animation,
  @required this.child,
}) : _positionAnimation = CurvedAnimation(
       parent: animation,
       curve: Curves.linearToEaseOut,
       // The curve must be flipped so that the reverse animation doesn't play
       // an ease-in curve, which iOS does not use.
       reverseCurve: Curves.linearToEaseOut.flipped,
     ).drive(_kBottomUpTween),
     super(key: key);

我们如何在 Dropdown 中更改 Flutter DropdownMenuItem 的宽度/填充？

Row(
  children: <Widget>[
    Expanded(
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          LightText(
            text: "Agent",
          ),
          Padding(
            padding: EdgeInsets.only(top: 3),
          ),
          Container(
            height: 27,
            child: Row(
              children: <Widget>[
                DropdownButtonHideUnderline(
                  child: DropdownButton<Agent>(
                    // isExpanded: true,
                    hint: Text(
                      agentName == null ? "" : agentName,
                      style: TextStyle(
                        fontSize: MediaQuery.of(context).size.width * 0.035,
                      ),
                    ),

                    value: selectedAgent,
                    onChanged: (Agent value) async {
                      selectedAgent = value;
                      agentName = selectedAgent.getAgentName();
                      agentId = selectedAgent.getAgentId();
                    },
                    items: agentList.map((Agent agent) {
                      return DropdownMenuItem<Agent>(
                        value: agent, …