1、libstdc++相关的3个库(libstdc++、libstdc++.6、libstdc++.6.0.9)在XCode10和iOS12中被移除
错误描述：
ld: library not found for -lstdc++.6.0.9
linker command failed with exit code 1(use -v to see invocation)
解决办法一：删除libstdc++，编译无错则不用适配，否则参考方法二
解决办法二：拷贝缺失的libstdc++
从XCode 9的目录里，把缺失的.tbd文件拷贝过来，要记得拷贝2套，一套是模拟器的，一套是真机的，文件路径如下：
真机：/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib
模拟器：/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib
2、与第三方的info.plist文件冲突
错误描述：
Showing Recent Messages
:-1: Multiple commands produce '/Users/wzm/Library/Developer/Xcode/DerivedData/MMC_SchoolShip-clbdywlcrnuhghgjrqctfnobowcr/Build/Products/Debug-iphoneos/MMC_SchoolShip.app/Info.plist':
1) Target 'MMC_SchoolShip' (project 'MMC_SchoolShip') has copy command from '/Users/wzm/Documents/MMC_SchoolShip/MMC_SchoolShip/MMVC/SCHChat/Vender/MJExtension/Info.plist' to '/Users/wzm/Library/Developer/Xcode/DerivedData/MMC_SchoolShip-clbdywlcrnuhghgjrqctfnobowcr/Build/Products/Debug-iphoneos/MMC_SchoolShip.app/Info.plist'
2) Target 'MMC_SchoolShip' (project 'MMC_SchoolShip') has copy command from '/Users/wzm/Documents/MMC_SchoolShip/MMC_SchoolShip/MMVC/SCHChat/Vender/Masonry/Info.plist' to '/Users/wzm/Library/Developer/Xcode/DerivedData/MMC_SchoolShip-clbdywlcrnuhghgjrqctfnobowcr/Build/Products/Debug-iphoneos/MMC_SchoolShip.app/Info.plist'
3) Target 'MMC_SchoolShip' (project 'MMC_SchoolShip') has process command with output '/Users/wzm/Library/Developer/Xcode/DerivedData/MMC_SchoolShip-clbdywlcrnuhghgjrqctfnobowcr/Build/Products/Debug-iphoneos/MMC_SchoolShip.app/Info.plist'
解决办法一：将第三方的info.plist删除
解决办法二：将第三方的info.plist文件重命名且保持唯一
解决办法三：如以上方法出错，参考下图设置Xcode
第一步
第二步
3、项目图标和启动图的调整
推荐一款快速生成项目图标的工具：APRO
App Store内搜索下载或点击下载链接
将生成的图片和Contents.json文件全部拖到对应的文件夹下，即可自动替换。
4、新版屏幕适配
#define IS_iPhone (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
#define SCREEN_SCALE [UIScreen mainScreen].scale
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height
#define iPhoneX (IS_iPhone && SCREEN_HEIGHT>=812) //iPhoneX系列
#define iPhone_5_8 (IS_iPhone && SCREEN_HEIGHT==812) //5.8寸
#define iPhone_6_1 (IS_iPhone && SCREEN_HEIGHT==896 && SCREEN_SCALE==2.0) //6.1寸
#define iPhone_6_5 (IS_iPhone && SCREEN_HEIGHT==896 && SCREEN_SCALE==3.0) //6.5寸
