Question

编译代码时收到以下错误。我正在尝试连接到一个sqlite 3数据库，并在输入到UIAlertView的文本中保存到表中，创建一个新列表。非常感谢所有帮助我花了好几个小时试图找出为什么这个错误被抛出因为sql文件在项目中，是使用sqlitebrowser创建的。

2014-12-04 19:10:29.917 SmartShop[7964:60b] -[DBManager initWithDatabaseFile:]:                                              unrecognized selector sent to instance 0x109239910
2014-12-04 19:10:29.925 SmartShop[7964:60b] *** Terminating app due to uncaught exception   'NSInvalidArgumentException', reason: '-[DBManager initWithDatabaseFile:]: unrecognized   selector sent to instance 0x109239910'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000101a35495 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x000000010179499e objc_exception_throw + 43
    2   CoreFoundation                      0x0000000101ac665d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x0000000101a26d8d ___forwarding___ + 973
    4   CoreFoundation                      0x0000000101a26938 _CF_forwarding_prep_0 + 120
    5   SmartShop                           0x0000000100001c62 -[ViewController viewDidLoad] + 114
    6   UIKit                               0x000000010043759e -[UIViewController loadViewIfRequired] + 562
    7   UIKit                               0x0000000100437777 -[UIViewController view] + 29
    8   UIKit                               0x00000001007422e2 -[UIClientRotationContext initWithClient:toOrientation:duration:andWindow:] + 390
    9   UIKit                               0x000000010037dffa -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:isRotating:] + 1109
    10  UIKit                               0x000000010037db9f -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:] + 36
    11  UIKit                               0x000000010037daef -[UIWindow _setRotatableViewOrientation:updateStatusBar:duration:force:] + 101
    12  UIKit                               0x000000010037cdfe -[UIWindow _updateToInterfaceOrientation:duration:force:] + 377
    13  UIKit                               0x000000010043b70a -[UIViewController _tryBecomeRootViewControllerInWindow:] + 147
    14  UIKit                               0x0000000100377b1b -[UIWindow addRootViewControllerViewIfPossible] + 490
    15  UIKit                               0x0000000100377c70 -[UIWindow _setHidden:forced:] + 282
    16  UIKit                               0x0000000100380ffa -[UIWindow makeKeyAndVisible] + 51
    17  UIKit                               0x000000010033cc98 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1788
    18  UIKit                               0x0000000100340a0c -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 660
    19  UIKit                               0x0000000100351d4c -[UIApplication handleEvent:withNewEvent:] + 3189
    20  UIKit                               0x0000000100352216 -[UIApplication sendEvent:] + 79
    21  UIKit                               0x0000000100342086 _UIApplicationHandleEvent + 578
    22  GraphicsServices                    0x0000000103bae71a _PurpleEventCallback + 762
    23  GraphicsServices                    0x0000000103bae1e1 PurpleEventCallback + 35
    24  CoreFoundation                      0x00000001019b7679 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 41
    25  CoreFoundation                      0x00000001019b744e __CFRunLoopDoSource1 + 478
    26  CoreFoundation                      0x00000001019e0903 __CFRunLoopRun + 1939
    27  CoreFoundation                      0x00000001019dfd83 CFRunLoopRunSpecific + 467
    28  UIKit                               0x00000001003402e1 -[UIApplication _run] + 609
    29  UIKit                               0x0000000100341e33 UIApplicationMain + 1010
    30  SmartShop                           0x0000000100002563 main + 115
    31  libdyld.dylib                       0x0000000101fba5fd start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

以下是来自ViewController的代码，引用了SQLite3数据库和其他代码。

#import "ViewController.h"
#import "DBManager.h"

@interface ViewController ()

@property (nonatomic, strong) DBManager *dbManager;

@end

@implementation ViewController


- (void)viewDidLoad
{
    [super viewDidLoad];

    // Initialize the dbManager object.
    self.dbManager = [[DBManager alloc] initWithDatabaseFile:@"shop.sql.sqbpro"];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)addNewList:(id)sender {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Add List" message:@"Enter              new list name:" delegate:self cancelButtonTitle:@"Add" otherButtonTitles:nil];
    alert.alertViewStyle = UIAlertViewStylePlainTextInput;
    UITextField *alertTextField = [alert textFieldAtIndex:0];
    alertTextField.placeholder = @"List name";
    [alert show];
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
    NSString *listName = [[alertView textFieldAtIndex:0] text];
    NSLog(@"ENTERED: %@",listName);

    //Prepare the query String
    NSString *query = [NSString stringWithFormat:@"insert into lists values(null, '%@')", listName];

    //Execute the query
    [self.dbManager executeQuery:query];

    //If successful pop the view controller
    if(self.dbManager.affectedRows != 0) {
        NSLog(@"Query was executed successfully. Affected rows = %d", self.dbManager.affectedRows);

        //Pop view controller
        [self.navigationController popViewControllerAnimated:YES];
    }
    else {
        NSLog(@"Could not execute the query.");
    }
}
@end

下面是我的initWithDatabaseFileName代码：

-(instancetype)initWithDatabaseFilename:(NSString *)dbFilename{
    self = [super init];
    if (self) {
        // Set the documents directory path to the documentsDirectory property.
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        self.documentsDirectory = [paths objectAtIndex:0];

        // Keep the database filename.
        self.databaseFilename = dbFilename;

        // Copy the database file into the documents directory if necessary.
        [self copyDatabaseIntoDocumentsDirectory];
    }
    return self;
}

Answer 1

您正在呼叫initWithDatabaseFile:，但该方法的名称为initWithDatabaseFilename:。

确保DBManager的.h文件具有与.m文件中的实际方法匹配的正确名称。

终止NSException的异常类型

1 个答案: