Flutter编译问题
1.Flutter编译时一直卡在"Resolving dependencies"
原因：国内被墙的原因
解决方案1：
配置系统环境变量：
-
PUB_HOSTED_URL->https://pub.flutter-io.cn -
FLUTTER_STORAGE_BASE_URL->https://storage.flutter-io.cn
最新的变量地址请访问：https://flutter.io/community/china
解决方案2：
在android目录的build.gradle下添加阿里镜像代理：
buildscript {
repositories {
maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'https://maven.aliyun.com/repository/jcenter' }
maven { url 'https://maven.aliyun.com/repository/public' }
maven { url 'https://maven.aliyun.com/repository/gradle-plugin' }
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.2.1'
}
}
allprojects {
repositories {
maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'https://maven.aliyun.com/repository/jcenter' }
maven { url 'https://maven.aliyun.com/repository/public' }
maven { url 'https://maven.aliyun.com/repository/gradle-plugin' }
google()
jcenter()
}
}
解决方案3：
使用翻墙工具构建
2.运行一些开源的项目编辑报错提示Finished with error: FormatException: Bad UTF-8 encoding 0xc3 (at offset 169)
原因：app的release版本找不到keystore文件
解决方案：
找到android->app目录下的build.gradle，找到buildTypes,修改release的signingConfigs.release为debug:
buildTypes {
debug {
signingConfig signingConfigs.debug
}
release {
signingConfig signingConfigs.debug
}
}
或者自己重新配置release的签名
Flutter开发问题
1.使用Navigator.push()跳转界面报错：
'Navigator operation requested with a context that does not include a Navigator.\n'
'The context used to push or pop routes from the Navigator must be that of a '
'widget that is a descendant of a Navigator widget.'
原因：传入的context不支持堆栈管理，比如一个类直接继承自StatelessWidget或StatefulWidget，而它本身或父类没有堆栈管理功能。那么这个类是不支持页面跳转的，所以就会报错。要查看是否支持页面跳转，直接进入源码，比如MaterialApp类，它是支持的，那么它的源码里会有对应的功能介绍：
/// See also:
///
/// * [Scaffold], which provides standard app elements like an [AppBar] and a [Drawer].
/// * [Navigator], which is used to manage the app's stack of pages. //这里做了对应的介绍
/// * [MaterialPageRoute], which defines an app page that transitions in a material-specific way.
/// * [WidgetsApp], which defines the basic app elements but does not depend on the material library.
/// * The Flutter Internationalization Tutorial,
/// <https://flutter.io/tutorials/internationalization/>.
class MaterialApp extends StatefulWidget {
.....
}
放一个报错的代码：
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Welcome to Flutter',
home: new Scaffold(
body:Container(
child: FlatButton(onPressed:(){
var push = Navigator.push(context,MaterialPageRoute(builder: (BuildContext context) {
return new OtherPager("我是从main传过去的值");
}));
push.then((value){
print("我是从上个页面传递回来的值$value");
});
}, child:new Icon(Icons.build)),
)
)
);
}
}
这里的MyApp是直接继承自StatelessWidget的，而在runApp()中直接使用了它，它没有父类而它本身也不支持界面的跳转，所以用它的context传入到Navigator中肯定是会报错的
解决方案
使用一个有堆栈管理功能的父类将MyApp类包裹，使其具有堆栈跳转功能
见如下代码：
void main() => runApp(MaterialApp(home: MyApp()));
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return new Scaffold(
body: Container(
child: FlatButton(
onPressed: () {
var push = Navigator.push(context,
MaterialPageRoute(builder: (BuildContext context) {
return new OtherPager("我是从main传过去的值");
}));
push.then((value) {
print("我是从上个页面传递回来的值$value");
});
},
child: new Icon(Icons.build)),
));
}
}
代码中将MaterialApp移出来了，直接将MyApp包裹了，那么MyApp的context就生效了，代码也不会报错啦。
