Swift敲代码时出现的错误总结

1. func touchesEnded(touches: Set, withEvent event: UIEvent) {}方法在xocde7.1中变为了：

func touchesEnded(touches:Set<UITouch>,withEvent event: UIEvent?) {}.   

否则会出现　method does not override any method…的错误。

2 . 出现Cannot convert value of type ‘[String: String?] to expected argument type ‘NSDictionary’ 的错误时，应检查定义的变量是否为OPtionl类型，如果是，在其后面加一个 ‘！’。

3.使用带throws方法时，应写成：

do{    // NSManagedObjectContext对象保存    try context.save()  }catch let error as NSError{    print(error.localizedDescription)  }  

4.Xcode7 使用NSURLSession发送HTTP请求的问题 :Application Transport Security has blocked a cleartext HTTP (http://) resource load since it is insecure. Temporary exceptions can be configured via your app’s Info.plist file.
应在plist文件中，加入：

<plist>  <dict>          ....      <key>NSAppTransportSecurity</key>      <dict>          <key>NSAllowsArbitraryLoads</key>          <true/>      </dict>  </dict>  </plist>  

中的部分代码
原因：在iOS9beta中，苹果将原http协议改成了https协议，使用 TLS1.2 SSL加密请求数据。

5.Swift2.0后，Swift中的find函数不能使用了，需要用到indexOf方法，以前的使用方式是：

let arr:Array = ["a","b","c"]find(arr, "c")!              // 2find(arr, "d")               // nil

现在需要改为(即使用indexOf方法)：

let arr = ["a","b","c"]let indexOfA = arr.indexOf("a") // 0let indexOfB = arr.indexOf("b") // 1let indexOfD = arr.indexOf("d") // nil

更详细的解释在：http://stackoverflow.com/questions/24028860/how-to-find-index-of-list-item-in-swift

6.在做跳转到注册和登录页面时出现了：Attempt to present on whose view is not in the window hierarchy! 的错误，它指的是要加载的ViewController并没有加载。这时应该是：由于在 viewDidLoad 里面调用引起的，解决办法是转移到 viewDidAppear 方法里面。
具体见：http://www.cnblogs.com/xunziji/p/4025009.html

7.在调用fmdb库时出现了以下的错误：

Ld /Users/user1319/Library/Developer/Xcode/DerivedData/Directory-app normal armv7    cd /Users/user1319/Desktop/app/app    setenv IPHONEOS_DEPLOYMENT_TARGET 5.0    setenv PATH "/Developer/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"    /Developer/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch armv7 -isysroot /Developer/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk -L/Users/user1319/Library/Developer/Xcode/DerivedData/app_Directory-bnkhohrmxdhrusarswxeqvxlljct/Build/Products/Distribution-iphoneos -F/Users/user1319/Library/Developer/Xcode/DerivedData/app-bnkhohrmxdhrusarswxeqvxlljct/Build/Products/Distribution-iphoneos -filelist "/Users/user1319/Library/Developer/Xcode/DerivedData/app-bnkhohrmxdhrusarswxeqvxlljct/Build/Intermediates/app Directory.build/Distribution-iphoneos/app.build/Objects-normal/armv7/app.LinkFileList" -Xlinker -rpath -Xlinker / -dead_strip -miphoneos-version-min=5.0 -lsqlite3 -lsqlite3.0 -framework AddressBook -framework AddressBookUI -framework UIKit -framework Foundation -framework CoreGraphics -o /Users/user1319/Library/Developer/Xcode/DerivedData/app-bnkhohrmxdhrusarswxeqvxlljct/Build/Products/Distribution-iphoneos/app.app/appld: warning: ignoring file /Developer/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/usr/lib/libsqlite3.dylib, missing required architecture armv7 in fileld: warning: ignoring file /Developer/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/usr/lib/libsqlite3.0.dylib, missing required architecture armv7 in fileUndefined symbols for architecture armv7:  "_sqlite3_reset", referenced from:      -[FMDatabase executeUpdate:error:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMStatement reset] in FMDatabase.o      -[FMResultSet next] in FMResultSet.o  "_sqlite3_bind_blob", referenced from:      -[FMDatabase bindObject:toColumn:inStatement:] in FMDatabase.o  "_sqlite3_changes", referenced from:      -[FMDatabase changes] in FMDatabase.o  "_sqlite3_prepare_v2", referenced from:      -[FMDatabase executeQuery:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMDatabase executeUpdate:error:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMDatabase(FMDatabaseAdditions) validateSQL:error:] in FMDatabaseAdditions.o  "_sqlite3_open", referenced from:      -[FMDatabase open] in FMDatabase.o  "_sqlite3_open_v2", referenced from:      -[FMDatabase openWithFlags:] in FMDatabase.o  "_sqlite3_bind_text", referenced from:      -[FMDatabase bindObject:toColumn:inStatement:] in FMDatabase.o  "_sqlite3_step", referenced from:      -[FMDatabase executeUpdate:error:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMResultSet next] in FMResultSet.o  "_sqlite3_next_stmt", referenced from:      -[FMDatabase close] in FMDatabase.o  "_sqlite3_bind_double", referenced from:      -[FMDatabase bindObject:toColumn:inStatement:] in FMDatabase.o  "_sqlite3_threadsafe", referenced from:      +[FMDatabase isThreadSafe] in FMDatabase.o  "_sqlite3_bind_int", referenced from:      -[FMDatabase bindObject:toColumn:inStatement:] in FMDatabase.o  "_sqlite3_last_insert_rowid", referenced from:      -[FMDatabase lastInsertRowId] in FMDatabase.o  "_sqlite3_column_blob", referenced from:      -[FMResultSet dataForColumnIndex:] in FMResultSet.o      -[FMResultSet dataNoCopyForColumnIndex:] in FMResultSet.o  "_sqlite3_finalize", referenced from:      -[FMDatabase close] in FMDatabase.o      -[FMDatabase executeQuery:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMDatabase executeUpdate:error:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMStatement close] in FMDatabase.o      -[FMDatabase(FMDatabaseAdditions) validateSQL:error:] in FMDatabaseAdditions.o  "_sqlite3_column_text", referenced from:      -[FMResultSet kvcMagic:] in FMResultSet.o      -[FMResultSet stringForColumnIndex:] in FMResultSet.o      -[FMResultSet UTF8StringForColumnIndex:] in FMResultSet.o  "_sqlite3_column_bytes", referenced from:      -[FMResultSet dataForColumnIndex:] in FMResultSet.o      -[FMResultSet dataNoCopyForColumnIndex:] in FMResultSet.o  "_sqlite3_column_int64", referenced from:      -[FMResultSet longForColumnIndex:] in FMResultSet.o      -[FMResultSet longLongIntForColumnIndex:] in FMResultSet.o  "_sqlite3_bind_parameter_count", referenced from:      -[FMDatabase executeQuery:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMDatabase executeUpdate:error:withArgumentsInArray:orVAList:] in FMDatabase.o  "_sqlite3_column_count", referenced from:      -[FMResultSet columnCount] in FMResultSet.o      -[FMResultSet setupColumnNames] in FMResultSet.o      -[FMResultSet kvcMagic:] in FMResultSet.o  "_sqlite3_column_name", referenced from:      -[FMResultSet setupColumnNames] in FMResultSet.o      -[FMResultSet kvcMagic:] in FMResultSet.o      -[FMResultSet columnNameForIndex:] in FMResultSet.o  "_sqlite3_errmsg", referenced from:      -[FMDatabase lastErrorMessage] in FMDatabase.o      -[FMDatabase executeUpdate:error:withArgumentsInArray:orVAList:] in FMDatabase.o      -[FMResultSet next] in FMResultSet.o  "_sqlite3_column_type", referenced from:      -[FMResultSet stringForColumnIndex:] in FMResultSet.o      -[FMResultSet dateForColumnIndex:] in FMResultSet.o      -[FMResultSet dataForColumnIndex:] in FMResultSet.o      -[FMResultSet dataNoCopyForColumnIndex:] in FMResultSet.o      -[FMResultSet columnIndexIsNull:] in FMResultSet.o      -[FMResultSet UTF8StringForColumnIndex:] in FMResultSet.o      -[FMResultSet objectForColumnIndex:] in FMResultSet.o...  "_sqlite3_libversion", referenced from:      +[FMDatabase sqliteLibVersion] in FMDatabase.o  "_sqlite3_errcode", referenced from:      -[FMDatabase lastErrorCode] in FMDatabase.o      -[FMResultSet hasAnotherRow] in FMResultSet.o  "_sqlite3_column_int", referenced from:      -[FMResultSet intForColumnIndex:] in FMResultSet.o  "_sqlite3_close", referenced from:      -[FMDatabase close] in FMDatabase.o  "_sqlite3_column_double", referenced from:      -[FMResultSet doubleForColumnIndex:] in FMResultSet.o  "_sqlite3_data_count", referenced from:      -[FMResultSet resultDict] in FMResultSet.o  "_sqlite3_bind_int64", referenced from:      -[FMDatabase bindObject:toColumn:inStatement:] in FMDatabase.o  "_sqlite3_bind_null", referenced from:      -[FMDatabase bindObject:toColumn:inStatement:] in FMDatabase.old: symbol(s) not found for architecture armv7clang: error: linker command failed with exit code 1 (use -v to see invocation)

解决办法：
1.到 Build Phases > Link Binary with Libraries > + > Add other
2.接着按快捷键 command”+shift+G （快速打开文件）到/ usr/lib/ 目录下
3.找到并一一添加 libz.dylib 和 ibsqlite3.dylib 文件，这样就OK了
具体参考：http://stackoverflow.com/questions/9762727/missing-required-architecture-armv7
http://stackoverflow.com/questions/31420166/libsqlite3-dylib-and-libz-dylib-missing-in-xcode-7-how-do-i-use-parse

8.ios8在UIViewController与xib文件关联时，会出现xib上的控件与视图控制器关联失败，运行时会出现控件为空：nil的错误。
解决办法：在视图控制器类的文件前加上一个@objc(类名)：

@objc(ViewController) class ViewController: UIViewController {}