Question

我在构建时遇到2个错误，它们位于AppDelegatem文件

中

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}

排除了两个错误：

self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];

错误1：

Receiver type "ViewController" for instance messages is a forward declaration

错误2：

Receiver "ViewController" for class messages is a forward declaration

与警报对齐：

self.window.rootViewController = self.viewController;

提醒：

Incompatible pointer types assigning to 'UIViewController *' from 'ViewController*'

如果需要，您可以找到的文本文件 ViewControllerm ViewControllerh AppDelegatem 这里http://ninjabreakbot.com/stack/

项目适用于iOS5，我对此非常陌生。请让我知道对此类问题有用的内容。或者，如果已经提供了足够的解决方案！

谢谢！

Answer 1

错误消息：instance messages is a forward declaration通常意味着编译器不知道类的声明，即您没有包含正确的标题。

在你的情况下，在AppDelegate.m的开头写#import <ViewController.h>应解决这个编译问题。

Answer 2

检查initWithNibName。是nib文件名ViewController还是其他名称？

写#import "ViewController.h"和 AppDelegate.h文件中的@property (strong, nonatomic) ViewController *viewController;

在AppDelegate.m文件中写@synthesize viewController ;

.h file ::

#import <UIKit/UIKit.h>
#import "ViewController.h"
@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) ViewController *viewController;

@end

.m file ::

#import "AppDelegate.h"
#import "ViewController.h"

@implementation AppDelegate

@synthesize window;
@synthesize viewController ;



- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController_iPhone" bundle:nil] autorelease];

    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}
@end

构建错误 - 实例消息的接收器类型“ViewController”是前向声明

2 个答案: