Flutter中没有上下文的AlertDialog [英] AlertDialog without context in Flutter

问题描述

我想在http获取失败时显示AlertDialog.函数showDialog( https://api.flutter.dev/flutter/material/showDialog.html)的参数为"@required BuildContext context"，但是我想从我的异步函数getNews()调用AlertDialog，该函数没有上下文值.

I want to show an AlertDialog when a http get fails. The function showDialog (https://api.flutter.dev/flutter/material/showDialog.html) has the parameter "@required BuildContext context", but I want to call the AlertDialog from my async function getNews(), which hasn't a context value.

与Java类似，在没有所有者的情况下，我使用null进行对话时，我尝试将上下文值设置为null，但不接受.

By analogy with Java, where I use null for dialog without an owner, I tried to put context value to null, but it is not accepted.

这是我的代码:

  Future<dynamic> getNews() async {
    dynamic retVal;
    try {
      var response = await http.get(url));
      if (response.statusCode == HttpStatus.ok) {
        retVal = jsonDecode(response.body);
      }
    } catch (e) {
      alertDlg(?????????, 'Error', e.toString());
  }
    return
    retVal;
  }

  static Future<void> alertDlg(context, String titolo, String messaggio) async {
    return showDialog<void>(
        context: context,
        barrierDismissible: false, // user must tap button!
        builder: (BuildContext context) {
        return AlertDialog(
              title: Text(titolo),
        ...
    );
  }

推荐答案

接受的答案是错误的.

对话框仅需要上下文即可通过继承的navigationState访问它.您可以创建自己的修改对话框，也可以使用此lib来完成此操作.

The dialog only needs the context to access it through an inherited navigateState. You can make your own modified dialog, or use this lib to do this.

https://pub.dev/packages/get

通过它，您可以从代码的任何位置打开对话框，而无需上下文:

With it you can open dialog from anywhere in your code without context by doing this:

Get.dialog(SimpleDialog());

这篇关于Flutter中没有上下文的AlertDialog的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！