app應用內中英文切換
工程-PROJECT-info->Localizations，點“+”，選擇（Chinese(Simplified)）新增簡體中文，英文Xcode自帶有（English），所以不需要再次新增。(點選新增彈出語言選單，即可選擇你所需要的語言)
2.現在可以新增多語言檔案了。
注意：需要手動切換語言，而不是根據系統語言變換，所以命名不能與系統語言檔案同名，即Localizable.strings；
自己隨意命名，字尾是.strings，一定要記得Targets要勾選專案
3.配置English.strings本地化，現在支援中文和英文。
(1)選中English.strings檔案，檢視右邊欄中的資訊；(2)點選Localization中的按鈕，彈出框中顯示出前面新增的語言；(3)選擇中文和英文，base選項可有可無，
勾選之後，English.strings中多出了兩個檔案
完成之後便是完成了專案內多語言環境的配置，下面看一下這兩個檔案中應該怎樣寫
4.檔案中新增需要的字串
中文：
"AirLeak" = "漏氣";
"AppUseDes" = "APP使用說明";
"AutoBind" = "自動繫結";
"AutoBindNewDevice" = "自動繫結";
"BackToDefaultSet" = "恢復預設設定";
"BatteryAlertDown" = "電量警報下限";
"BindNewDevice" = "繫結新裝置";
"BleOpen" = "藍芽開啟";
"Cancel" = "取消";
"DeviceHasBeenBD"
"DeviceInstallDes" = "裝置安裝說明";
"Ensure" = "確定";
"FindNewDevice" = "發現新版本";
"HighTempreture" = "溫度過高";
"Help" = "幫助";
"HighPressure" = "氣壓過高";
"Home" = "首頁";
"InputRightCode" = "請輸入正確的編號";
"InputWheelCode" = "請輸入輪胎編碼\n(由0-9，a-f，A-F組成)";
"LowBattery" = "電量低";
"LowPressure" = "氣壓低";
"ManualBindNewDevice"
"ManualBind" = "手動繫結";
"PleaseBindDevice" = "請繫結裝置";
"PleaseOpenBle" = "請開啟藍芽";
"PressureAlertDown" = "壓力警告下限";
"PressureAlertUpper" = "壓力警告上限";
"PressureUnint" = "壓力單位";
"Searching" = "搜尋中";
"SharkAlert" = "震動報警";
"SystemSet" = "系統設定";
"TempretureAlertUpper" = "溫度警告上限";
"TempretureUnint" = "溫度單位";
"LeftUpWheel" = "左前輪胎";
"RightUpWheel" = "右前輪胎";
"LeftDownWheel" = "左後輪胎";
"RightDownWheel" = "右後輪胎";
"RotationType" = "調胎";
"ScanAndScan" = "掃一掃";//掃一掃
"AlbumLab" = "相簿";
"ChooseQRCodePic" = "請選擇二維碼圖片";
"ChooseSure" = "確認";
"ScanCodeSuccess" = "掃碼繫結成功";//掃碼繫結成功
"ScanRepeat" = "請重新掃描";//請重新掃描
"ScanBind" = "掃碼繫結";//掃碼繫結
英文："AirLeak" = "Air leak";
"AppUseDes" = "app use manual";
"AutoBind" = "Auto bind";
"AutoBindNewDevice" = "Auto bind";
"BackToDefaultSet" = "Restore default setting";
"BatteryAlertDown" = "Minimum alert battery";
"BindNewDevice" = "Bind new sensor";
"BleOpen" = "Ble enabled";
"Cancel" = "Cancel";
"DeviceHasBeenBD" = "Device has been bound";
"DeviceInstallDes" = "device install instructions";
"Ensure" = "Ok";
"FindNewDevice" = "New version";
"HighTempreture" = "High temperature";
"Help" = "Help";
"HighPressure" = "High pressure";
"Home" = "Home";
"InputRightCode" = "Input correct code";
"InputWheelCode" = "Input wheel code";
"LowBattery" = "Low battery ";
"LowPressure" = "Low pressure";
"ManualBindNewDevice" = "Manual bind";
"ManualBind" = "manual bind";
"PleaseBindDevice" = "Please bind sensor";
"PleaseOpenBle" = "Enable ble";
"PressureAlertDown" = "Minimum alert pressure";
"PressureAlertUpper" = "Maximum alert pressure";
"PressureUnint" = "Pressure unit ";
"Searching" = "Searching";
"SharkAlert" = "Vibration alert";
"SystemSet" = "System setting";
"TempretureAlertUpper" = "Maximum alert temperature";
"TempretureUnint" = "Temperature unit";
"LeftUpWheel" = "Left up wheal";
"RightUpWheel" = "Right up wheal";
"LeftDownWheel" = "Left down Wheal";
"RightDownWheel" = "Right down wheal";
"RotationType" = "Tyre rotation";
"ScanAndScan" = "Scan";//掃一掃
"AlbumLab" = "Album";
"ChooseQRCodePic" = "Please choose a pic of QRCode";
"ChooseSure" = "sure";
"ScanCodeSuccess" = "Scan success";//掃碼繫結成功
"ScanRepeat" = "Scan repeat";//請重新掃描
"ScanBind" = "Scan bind";//掃碼繫結
5.配置環境已經完成，現在看看程式碼怎麼寫？？？？
（1）新建立工具類，繼承自NSObject(在這裡我命名為ChangeLanguage)
（2）ChangeLanguage.h
+(NSBundle *)bundle;//獲取當前資原始檔
+(void)initUserLanguage;//初始化語言檔案
+(NSString *)userLanguage;//獲取應用當前語言
+(void)setUserlanguage:(NSString *)language;//設定當前語言
ChangeLanguage.m