Objecttive-C各种问题

1.invalid argument type 'void' to unary expression

@try{
        if (![mJQFMDB open]) {
            NSLog(@"Could not open db.");
            return NO;
        }else {
            NSArray *mLineInfoAry = responseObject[@"Data"];
            if(mLineInfoAry != nil && mLineInfoAry.count > 0) {
                for (NSDictionary *lineInfo in mLineInfoAry) {
                    
                }
            }
            return YES;
        }
    }@catch(NSException *ex) {
        [TExUtils uploadEx:ex];
    }@finally {
        [mFMDB close];
    }

该类继承父类，父类成员变量如下：

@interface BasicDataBase : NSObject {
    //成员变量
    @public
    FMDatabase *mFMDB;
    @public
    JQFMDB *mJQFMDB;
}