fetch faild in reactnative

fetch在ReactNative中可能会报错如下：Possible unhandled promise rejection (id:0: Network request failed

According to this post, you should enable it in XCode.

1. Click on your project in the Project Navigator
2. Open the Info tab
3. Click on the down arrow left to the “App Transport Security Settings”
4. Right click on “App Transport Security Settings” and select Add Row
5. For created row set the key “Allow Arbitrary Loads“, type to boolean and value to YES.