Problem 1
- yiisoft/yii2 2.0.x-dev requires ext-mbstring * -> the requested PHP extens
ion mbstring is missing from your system.
- yiisoft/yii2 2.0.9 requires ext-mbstring * -> the requested PHP extension
mbstring is missing from your system.
- yiisoft/yii2 2.0.8 requires ext-mbstring * -> the requested PHP extension
mbstring is missing from your system.
- yiisoft/yii2 2.0.7 requires ext-mbstring * -> the requested PHP extension
mbstring is missing from your system.
- yiisoft/yii2 2.0.6 requires ext-mbstring * -> the requested PHP extension
mbstring is missing from your system.
- Installation request for yiisoft/yii2 ~2.0.6 -> satisfiable by yiisoft/yii
2[2.0.6, 2.0.7, 2.0.8, 2.0.9, 2.0.x-dev].
To enable extensions, verify that they are enabled in those .ini files:
- I:android_developerhttpd2.4phpphp.ini
You can also run `php --ini` inside terminal to see which files are used by PH
P in CLI mode.
解决：
找到php.ini打开extension=php_mbstring.dll
报错：
Deprecation Notice: The ComposerPackageLinkConstraintMultiConstraint class is deprecated, use ComposerSemverConstraintMultiConstraint instead . in phar://C:/ProgramData/ComposerSetup/bin/composer.phar/src/Composer/Package/LinkConstraint/MultiConstraint.php:17
解决：
composer global require "fxp/composer-asset-plugin:~1.0.0"
修改成
composer global require "fxp/composer-asset-plugin:~1.2.1"
报错:
The openssl extension is required for SSL/TLS protection but is not available. If you can not enable the openssl extension, you can disable this error, at your own risk, by setting the 'disable-tls' option to true.
解决：
You should go to XAMPP php.ini and remove the semicolum from: extension=php_openssl.dll
参考：
https://teamtreehouse.com/community/openssl-extension-is-required