Flutter：从另一个 Dart 文件获取 AlertDialog

Question

我需要帮助伙计们。我有 2 个 dart 文件：main.dart 和 alertform.dart。有些情况需要在我的应用程序中使用这种方法。我想尝试在 main.dart 上的按钮上从 alertform.dart 访问 alerdialog。那可能吗？这是我的代码：

main.dart

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

class MainPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: new Text('Test'),
      ),
      body: new Column(
        children: <Widget>[
          RaisedButton(
            child: new Text('Show Alert'),
            onPressed: (){
              CommentForm();
            },
          )
        ],
      ),
    );
  }
}

alertform.dart

import 'package:flutter/material.dart';

class AlertForm extends StatefulWidget {
  @override
  _AlertFormState createState() => _AlertFormState();
}

class _AlertFormState extends State<AlertForm> {

    void _showDialog() {
    // flutter defined function
    showDialog(
      context: context,
      builder: (BuildContext context) {
        // return object of type Dialog
        return AlertDialog(
          title: new Text("Alert Dialog title"),
          content: new Text("Alert Dialog body"),
          actions: <Widget>[
            // usually buttons at the bottom of the dialog
            new FlatButton(
              child: new Text("Close"),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }


  @override
  Widget build(BuildContext context) {
    return Container(

    );
  }
}

Answer 1

我不知道你为什么要从课外调用这个 _dialog，在那里你可以在你的课内调用。但是如果你想这样做，你可以试试这个代码。

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

class MainPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: new Text('Test'),
      ),
      body: new Column(
        children: <Widget>[
          RaisedButton(
            child: new Text('Show Alert'),
            onPressed: (){
              AlertFormState(context).showDialogBox;
            },
          )
        ],
      ),
    );
  }
}**

import 'package:flutter/material.dart';

class AlertForm extends StatefulWidget {
  @override
  AlertFormState createState() => AlertFormState();
}

class AlertFormState extends State<AlertForm> {

    void showDialogBox(BuildContext context) {
    // flutter defined function
    showDialog(
      context: context,
      builder: (BuildContext context) {
        // return object of type Dialog
        return AlertDialog(
          title: new Text("Alert Dialog title"),
          content: new Text("Alert Dialog body"),
          actions: <Widget>[
            // usually buttons at the bottom of the dialog
            new FlatButton(
              child: new Text("Close"),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }


  @override
  Widget build(BuildContext context) {
    return Container(

    );
  }
}