ios - 更改build设置以编译 SQLCipher 后 FMDB 类出现 ARC 错误

Question

我遵循了使用位于此处的二进制文件在 iOS 设备上编译 SQLCipher 的教程:http://sqlcipher.net/sqlcipher-binaries-ios-and-osx/

我对build设置进行了多项更改，添加了 header 搜索路径和 cflags。然后在测试了 sqlcipher 的编译后，二进制文件没有出现任何错误，但是 FMDB 之前不存在的错误开始显示如下:

FMDatabaseAdditions.m:137:19: Implicit declaration of function 'NSFileTypeForHFSTypeCode' is invalid in C99`

FMDatabaseAdditions.m:137:19: Implicit conversion of 'int' to 'NSString *' is disallowed with ARC`

FMDatabaseAdditions.m:137:15: Incompatible integer to pointer conversion initializing 'NSString *__strong' with an expression of type 'int'`

FMDatabaseAdditions.m:158:96: Values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead`

FMDatabaseAdditions.m:161:28: Implicit declaration of function 'NSHFSTypeCodeFromFileType' is invalid in C99`

Answer 1

当您在项目中使用目标时会发生此错误。 NSFileTypeForHFSTypeCode 仅在针对 Mac OS 目标编译项目时才需要，如果目标是 iPhone，则不应使用。实际上，在新版本的 XCode 上，即使您的项目定位为 iPhone ，似乎也会发生错误。 旧答案:

所以我们必须重写 applicationIDString 实现并放置条件标志:

    #if TARGET_OS_MAC && !TARGET_OS_IPHONE
    - (NSString*)applicationIDString {
       NSString *s = NSFileTypeForHFSTypeCode([self applicationID]);

       assert([s length] == 6);

       s = [s substringWithRange:NSMakeRange(1, 4)];


       return s;

    }
#endif

如果 TARGET_OS_MAC 不会取代 !TARGET_OS_IPHONE 的需要，因为 TARGET_OS_IPHONE 实际上是 TARGET_OS_MAC 的变体。所以为了避免编译错误，添加#if TARGET_OS_MAC && !TARGET_OS_IPHONE

也在这部分代码下面:

    - (void)setApplicationIDString:(NSString*)s {

       if ([s length] != 4) {
          NSLog(@"setApplicationIDString: string passed is not exactly 4 chars long. (was %ld)", [s length]);
       }
        #if TARGET_OS_MAC && !TARGET_OS_IPHONE
       [self setApplicationID:NSHFSTypeCodeFromFileType([NSString stringWithFormat:@"'%@'", s])];
       #endif
   }

新答案:

我更新了代码并重新安排了方法，以便在 FMDatabaseAdditions.m 中根据范围(条件)进行更多分组:

        #if SQLITE_VERSION_NUMBER >= 3007017

        - (uint32_t)applicationID {

            uint32_t r = 0;

            FMResultSet *rs = [self executeQuery:@"pragma application_id"];

            if ([rs next]) {
                r = (uint32_t)[rs longLongIntForColumnIndex:0];
            }

            [rs close];

            return r;
        }

        - (void)setApplicationID:(uint32_t)appID {
            NSString *query = [NSString stringWithFormat:@"pragma application_id=%d", appID];
            FMResultSet *rs = [self executeQuery:query];
            [rs next];
            [rs close];
        }


        #if TARGET_OS_MAC && !TARGET_OS_IPHONE
        - (NSString*)applicationIDString {
            NSString *s = NSFileTypeForHFSTypeCode([self applicationID]);

            assert([s length] == 6);

            s = [s substringWithRange:NSMakeRange(1, 4)];


            return s;

        }

        - (void)setApplicationIDString:(NSString*)s {

            if ([s length] != 4) {
                NSLog(@"setApplicationIDString: string passed is not exactly 4 chars long. (was %ld)", [s length]);
            }

            [self setApplicationID:NSHFSTypeCodeFromFileType([NSString stringWithFormat:@"'%@'", s])];
        }


        #endif

        #endif

同时为了避免其他警告，我修改了 FMDatabaseAdditions.h

       #if SQLITE_VERSION_NUMBER >= 3007017

        ///-----------------------------------
        /// @name Application identifier tasks
        ///-----------------------------------

        /** Retrieve application ID

         @return The `uint32_t` numeric value of the application ID.

         @see setApplicationID:
         */

        - (uint32_t)applicationID;

        /** Set the application ID

         @param appID The `uint32_t` numeric value of the application ID.

         @see applicationID
         */

        - (void)setApplicationID:(uint32_t)appID;

        #if TARGET_OS_MAC && !TARGET_OS_IPHONE
        /** Retrieve application ID string

         @return The `NSString` value of the application ID.

         @see setApplicationIDString:
         */


        - (NSString*)applicationIDString;

        /** Set the application ID string

         @param string The `NSString` value of the application ID.

         @see applicationIDString
         */

        - (void)setApplicationIDString:(NSString*)string;
        #endif

        #endif