Question

也许这是一个愚蠢的问题但是我在子视图中切换视图时遇到了问题。让我解释一下代码结构：

我有这些类文件：

/classes/MySoftwareAppDelegate.h
/classes/MySoftwareAppDelegate.m
/classes/ViewController.h
/classes/ViewController.m
/classes/LoginController.h
/classes/LoginController.m
/classes/CustomersController.h
/classes/CustomersController.m

我有这些观点：

/resources/MainWindow.xib
/resources/Login.xib
/resources/Customers.xib

在AppDelegate中，我已成功插入子视图“Login”，并在应用程序启动时显示。

在登录视图中，输入我的用户名和密码，然后单击“登录”按钮。单击此按钮时，将触发IBAction。在这个IBAction中，我想用Customers更改当前的子视图。

这是我用过的代码：

MySoftwareAppDelegate.h

#import <UIKit/UIKit.h>

@class ViewController;

@interface MySoftwareAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
 ViewController *viewController;
}

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

@end

MySoftwareAppDelegate.m

#import "MySoftwareAppDelegate.h"
#import "ViewController.h"

@implementation MySoftwareAppDelegate

@synthesize window;
@synthesize viewController;


- (void)applicationDidFinishLaunching:(UIApplication *)application {    

    // Override point for customization after application launch
 [window addSubview:viewController.view];
    [window makeKeyAndVisible];
}


- (void)dealloc {
 [viewController release];
    [window release];
    [super dealloc];
}


@end

ViewController.h

#import <UIKit/UIKit.h>

@class LoginController;

@interface ViewController : UIViewController {
 LoginController *loginController;
}

@property (nonatomic, retain) LoginController *loginController;

@end

ViewController.m

#import "ViewController.h"
#import "LoginController.h"

@implementation ViewController

@synthesize loginController;

- (void)viewDidLoad {
 LoginController *tmpViewController = [[LoginController alloc] initWithNibName:@"Login" bundle:nil];

 self.loginController = tmpViewController;
 [self.view insertSubview:loginController.view atIndex:0];

 [tmpViewController release];

    [super viewDidLoad];
}

- (void)didReceiveMemoryWarning {
 // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

 if (self.loginController.view.superview == nil) {
  self.loginController = nil;
 }

 // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
 // Release any retained subviews of the main view.
 // e.g. self.myOutlet = nil;
}


- (void)dealloc {
 [loginController release];
    [super dealloc];
}

@end

LoginController.h

#import <UIKit/UIKit.h>

@class CustomersController;

@interface LoginController : UIViewController {
 UIButton *loginButton;
 UITextField *usernameTextField;
 UITextField *passwordTextField;
 NSMutableString *available_credits;
 NSString *current_xml_element;
 CustomersController *customersController;
}

@property (nonatomic, retain) IBOutlet UIButton *loginButton;
@property (nonatomic, retain) IBOutlet UITextField *usernameTextField;
@property (nonatomic, retain) IBOutlet UITextField *passwordTextField;
@property (nonatomic, retain) NSMutableString *available_credits;
@property (nonatomic, retain) NSString *current_xml_element;
@property (nonatomic, retain) CustomersController *customersController;

-(IBAction)textFieldDoneEditing:(id)sender;
-(IBAction)backgroundTap:(id)sender;
-(IBAction)loginToAccount:(id)sender;

@end

LoginController.m

#import "LoginController.h"
#import "CustomersController.h"

@implementation LoginController

@synthesize loginButton;
@synthesize usernameTextField;
@synthesize passwordTextField;
@synthesize customersController;

- (void)viewDidLoad {
 UIImage *buttonImageNormal = [UIImage imageNamed:@"whiteButton.png"];
 UIImage *stretchableButtonImageNormal = [buttonImageNormal stretchableImageWithLeftCapWidth:12 topCapHeight:0];
 UIImage *buttonImagePressed = [UIImage imageNamed:@"blueButton.png"];
 UIImage *stretchableButtonImagePressed = [buttonImagePressed stretchableImageWithLeftCapWidth:12 topCapHeight:0]; 

 [loginButton setBackgroundImage:stretchableButtonImageNormal forState:UIControlStateNormal];
 [loginButton setBackgroundImage:stretchableButtonImagePressed forState:UIControlStateHighlighted];
}

- (void)didReceiveMemoryWarning {
 // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning]; 
 // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
 // Release any retained subviews of the main view.
 // e.g. self.myOutlet = nil;
}

- (void)dealloc {
 [usernameTextField release];
 [passwordTextField release];
    [super dealloc];
}

-(IBAction)textFieldDoneEditing:(id)sender {
 [sender resignFirstResponder];
}

-(IBAction)backgroundTap:(id)sender {
 [usernameTextField resignFirstResponder];
 [passwordTextField resignFirstResponder];
}

-(IBAction)loginToAccount:(id)sender {

 // bla bla bla... Login check process is done here

 CustomersController *tmpViewController = [[CustomersController alloc] initWithNibName:@"Customers" bundle:nil];
 self.customersController = tmpViewController;

 [self.view removeFromSuperview];

 [tmpViewController release];

}

@end

如上所示，在LoginController.m的loginToAccount方法中，我正在检查登录信息，然后为“customers”子视图设置新的视图控制器。

然后我从超级视图中删除当前的“Login”子视图，但不知道如何添加新的“Customers”子视图。

在MainWindow.xib中，我有一个链接到ViewController类的视图控制器，它是根控制器。

感谢任何帮助。因为我是Objective-C和iPhone编程的新手，所以请尽量解释一下新手程序员的问题：）

再次感谢。

Answer 1

您没有向视图层次结构添加任何视图，只是删除了登录视图控制器。如果要将客户视图添加到视图层次结构中，则应使用：

CustomersController *tmpViewController = [[CustomersController alloc] initWithNibName:@"Customers" bundle:nil];
self.customersController = tmpViewController;
[self presentModalViewController:tmpViewController]

上述方法将确保在帐户视图控制器上调用viewWillLoad，didLoad等。它还将为您删除和添加正确的视图到视图层次结构。

从子视图切换视图有问题

1 个答案: