# 学习途径

1.Effevtive Dart

http://dart.goodev.org/guides/language/effective-dart/

# FLutter-Tips 开发中遇到的点点滴滴记录

1.iOS 'Flutter/Flutter.h' file not found

In file included from /Users/mt/.pub-cache/hosted/pub.flutter-io.cn/flutter_webview_plugin-0.2.1+2/ios/Classes/FlutterWebviewPlugin.m:1:
/Users/mt/.pub-cache/hosted/pub.flutter-io.cn/flutter_webview_plugin-0.2.1+2/ios/Classes/FlutterWebviewPlugin.h:1:9: fatal error: 'Flutter/Flutter.h' file not found
#import <Flutter/Flutter.h>
        ^~~~~~~~~~~~~~~~~~~
1 error generated.

这个解决了 大家如果也遇到了 可以尝试

• 在项目根目录运行 flutter clean
• 删除ios/podfile.lock 再运行

2.目前这个版本还存在编译问题，flutter官方也在积极解决

真机运行报错couldn't find "libflutter.so"

暂时的解决方法有：

build.gradle设置

ndk{
     abiFilters 'armeabi', 'armeabi-v7a'//, 'arm64-v8a'
}

或者可以增加编译选项：

--target-platform android-arm64 或者 --target-platform android-arm

注意~~~~~~~~~~~~~~~~~~~~~~~~~~~了
app/build.gradle文件
defaultConfig节点下

打正式包(加入NDK限制)
        ndk {
            abiFilters 'armeabi-v7a'//'armeabi', 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64', 'mips', 'mips64'
        }
打测试包(注释掉NDK代码)

3.'_InternalLinkedHashMap<dynamic, dynamic>' is not a subtype of type 'Map<String, dynamic>'

解决办法: new Map<String, dynamic>.from(snapshot.value);

引用自:flutter/flutter#16589

4.TextField限制字数

如果需要字数提示框 就用maxLength:11 如果不需要字数提示框就用

inputFormatters: <TextInputFormatter>[
    WhitelistingTextInputFormatter.digitsOnly, //限制输入格式
    LengthLimitingTextInputFormatter(11),// 限制字数
]

5.继承key :super(key:key)的意义

widget绑定key时，如果没有继承就会找不到这个widget

6.页面保持状态

继承AutomaticKeepAliveClientMixin，并实现

@override
bool get wantKeepAlive => true;

重点注意: 使用AutomaticKeepAliveClientMixin还要在build函数里写super.build()

@override
Widget build(BuildContext context) {
   super.build(context);
   return Container();
}

7.Android WebView无法在https下加载http资源 (表现为某些http视频资源无法播放)

在webview加载页面之前，设置加载模式为MIXED_CONTENT_ALWAYS_ALLOW

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
   webView.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
}

8.Navigator pop to root

Navigator.popUntil(context, (Route<dynamic> route) => route.isFirst)

9.ListView foreach如何获取index

List _sample = ['a','b','c'];
_sample.asMap().forEach((index, value) => f);

引用自:https://stackoverflow.com/questions/54898767/enumerate-or-map-through-a-list-with-index-and-value-in-dart

移除__MAXOSX文件夹
zip -d filename.zip __MACOSX/\*