“方法”实施在哪里？ （我是新手）

Question

我有这段代码：

#import "SQLiteDB.h"

@implementation SQLiteDB

@synthesize db, dbPath, databaseKey;

@end



//--------------    check for database or create it    ----------------|

- (void)checkForDatabase  {

    NSFileManager *filemanager = [NSFileManager defaultManager];
    NSString *databasePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] 
                              stringByAppendingString:@"/ppcipher.s3db"];

    if(![filemanager fileExistsAtPath:databasePath]) {  //Database doesn't exist yet, so we create it...
        NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingString:@"/ppcipher.s3db"];

        sqlite3 *db;
        if(sqlite3_open(databasePath, db) == SQLITE_OK)  {

        }

    }
}

它抱怨“方法定义不在@implementation上下文中”。那它去哪儿了？ （我试过.h文件，但仍然得到错误）

Answer 1

方法实施必须在@implementation和@end之间进行。那就是：

#import "SQLiteDB.h"

@implementation SQLiteDB

@synthesize db, dbPath, databaseKey;

-(void) checkForDatabase {

    ...

}

@end

Answer 2

它应该在@implementation block里面

#import "SQLiteDB.h"

@implementation SQLiteDB

@synthesize db, dbPath, databaseKey;



//--------------    check for database or create it    ----------------|

- (void)checkForDatabase  {

    NSFileManager *filemanager = [NSFileManager defaultManager];
    NSString *databasePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] 
                              stringByAppendingString:@"/ppcipher.s3db"];

    if(![filemanager fileExistsAtPath:databasePath]) {  //Database doesn't exist yet, so we create it...
        NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingString:@"/ppcipher.s3db"];

        sqlite3 *db;
        if(sqlite3_open(databasePath, db) == SQLITE_OK)  {

        }

    }
}

@end