flutter开发问题问题汇总

问题一：解决pods-frameworks.sh:permission denied问题
打包的代码在其他电脑中打开，无法在iOS模拟器中运行，报错具体信息：

11111.png

最终解决方案为：
在终端输入
chmod a+x “/Users/***/Pods/Pods-resources.sh”
***为pods文件夹所在路径

33.png

问题二：

Warning! This package referenced a Flutter repository via the .packages file that is no longer available. The repository from which the 'flutter' tool is currently executing will be used instead.
  running Flutter tool: /Users/***/development/flutter
  previous reference  : /E:/development/flutter
This can happen if you deleted or moved your copy of the Flutter repository, or if it was on a volume that is no longer mounted or has been mounted at a different location. Please check your system path to verify that you are running the expected version (run 'flutter --version' to see which flutter is on your path).

a、在终端中实例SDK路径：
flutter config --android-sdk /path/to/android/sdk
b、在Android studio中，选择Tools -> Flutter -> Flutter Clean。
如果问题依然没有解决，请查看环境变量路径配置是否正确、是否缺少，项目设置中flutter sdk的路径是否正确

问题三：

The argument type 'CachedNetworkImage' can't be assigned to the parameter type 'ImageProvider'. 

解决方法1：
该cached_image_network提供class的是extends ImageProvider，即CachedNetworkImageProvider：

Container(
  width: 80.0,
  height: 80.0,
  decoration: BoxDecoration(
    shape: BoxShape.circle,
    image: DecorationImage(
      image: CachedNetworkImageProvider('https://p.ssl.qhimg.com/dmfd/400_300_/t010774c3ffd8c986a2.jpg
'),
    ),
  ),
)

解决方法2：
因为BoxDecoration 可以在任何小Widget上使用，所以我们可以省略DecorationImage小部件来实现：

Container(
  width: 80.0,
  height: 80.0,
  decoration: BoxDecoration(
    shape: BoxShape.circle,
  ),
  child: CachedNetworkImage('https://p.ssl.qhimg.com/dmfd/400_300_/t010774c3ffd8c986a2.jpg
'),
)

问题四：APP打包安装后无法访问网络
缺少网络权限：

<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

在android/src/main/AndroidManifest.xml中添加以上权限使用申请的配置，打包再次安装就可以访问网路了

问题五：

Launching lib\main.dart on Android SDK built for x86 in debug mode...
Initializing gradle...

启动后一直处于这种状态下，一般是gradle文件下载不了的情况。可以尝试自己下载gradle文件，我的是4.10.2版本，下载之后，
找到自己机子里gradle的存放路径，这个路径是隐藏的，我的在C:\Users\xxx.gradle\wrapper\dists\gradle-4.10.2-all\9fahxiiecdb76a5g3aw9oi8rv下，把下载的zip包复制到这里并解压，重新运行。

问题六：

Launching lib/main.dart on Android SDK built for x86 in debug mode...
Initializing gradle...
Resolving dependencies...
* Error running Gradle:
ProcessException: Process "/Users/xxx/develop/android/flutter_app/android/gradlew" exited abnormally:
Project evaluation failed including an error in afterEvaluate {}. Run with --stacktrace for details of the afterEvaluate {} error.

FAILURE: Build failed with an exception.

......

Finished with error: Please review your Gradle project setup in the android/ folder.

出现这样的错误提示，通常是网络无法翻墙造成的，但是也不排除一些同学没有完成环境变量的配置，所以请先检查在系统环境变量中是否配置了ANDROID_HOME的路径，在用户变量中的Path中，是否配置添加了%ANDROID_HOME%tools
如果问题依然没有解决？咱们继续：
步骤1、
修改build.gradle,注释掉jcenter()，google()，使用阿里的镜像

buildscript {
    repositories {
        //google()
        //jcenter()
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
    }
}

allprojects {
    repositories {
        //google()
        //jcenter()
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }
    }
}

步骤2、
找到flutterSDK目录,我的是下载保持到了D盘，
D:\development\flutter\packages\flutter_tools\gradle
找到下 flutter.gradle文件 找如如下内容替换成和我一样的 把jcenter注释掉。

​buildscript {
    repositories {
        //jcenter()
        //maven {
        //    url 'https://dl.google.com/dl/android/maven2'
        //}
        maven{
            url 'https://maven.aliyun.com/repository/jcenter'
        }
        maven{
            url 'http://maven.aliyun.com/nexus/content/groups/public'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
    }
}