如何在“loadView”之外创建的按钮方法中更改“self.view”

Posted 2023-03-21

【中文标题】如何在“loadView”之外创建的按钮方法中更改“self.view”

【英文标题】：How can I change 'self.view' within a button method created outside of 'loadView'

【发布时间】：2010-03-11 13:57:33

【问题描述】：

大家好。所以我在 loadView 中动态创建按钮。这些按钮中的每一个都使用@Selector 方法赋予了一个动作，例如：

[button addTarget:self action:@selector(showCCView) forControlEvents:UIControlEventTouchUpInside];

现在 showCCView 方法是在 loadView 之外定义的，即上面的语句所在的位置。该方法的重点是改变当前屏幕上的视图（所以设置 self.view = ccView）。每次我尝试在 loadView 之外访问 self.view 时，它都会给我一个错误，甚至有时当我尝试在 loadView 内的随机位置访问它时，它的行为真的很奇怪。

我试图改变它，这样我也不必处理这个问题。我做了一个函数 + (void) showView: (UIView*) oldView: (UIView*) newView;但这也没有奏效，因为 @Selector 对于将它与需要两个参数的函数一起使用时确实很棘手。

有什么帮助吗？

这是我的代码：

    //
//  SiteOneController.m
//  InstantNavigator
//
//  Created by dni on 2/22/10.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//

#import "SiteOneController.h"


@implementation SiteOneController

+ (UIView*) ccContent 

    UIView *ccContent = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];

    ccContent.backgroundColor = [UIColor whiteColor];

    [ccContent addSubview:[SiteOneController myNavBar1:@"Constitution Center Content"]];
    return ccContent;


// Button Dimensions
int a = 62;
int b = 80;
int c = 200;
int d = 30;

// NPSIN Green Color
+ (UIColor*)myColor1   
    return [UIColor colorWithRed:0.0f/255.0f green:76.0f/255.0f blue:29.0f/255.0f alpha:1.0f];


// Creates Nav Bar with default Green at top of screen with given String as title
+ (UINavigationBar*)myNavBar1: (NSString*)input 

    UIView *test = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0.0, 0.0, test.bounds.size.width, 45)];
    navBar.tintColor = [SiteOneController myColor1];

    UINavigationItem *navItem;
    navItem = [UINavigationItem alloc];
    navItem.title = input;
    [navBar pushNavigationItem:navItem animated:false];

    return navBar;



//-------------------------------------------------------------------------------------------//
//-------------------------------------------------------------------------------------------//
//-------------------------------------------------------------------------------------------//


 // Implement loadView to create a view hierarchy programmatically, without using a nib.
 - (void)loadView 

     //hard coded array of content for each site

     // CC
     NSMutableArray *allccContent = [[NSMutableArray alloc] init];

     NSString *cc1 = @"House Model";
     NSString *cc2 = @"James Dexter History";

     [allccContent addObject: cc1];
     [cc1 release];

     [allccContent addObject: cc2];
     [cc2 release];

     // FC
     NSMutableArray *allfcContent = [[NSMutableArray alloc] init];

     NSString *fc1 = @"Ghost House";
     NSString *fc2 = @"Franklins Letters";
     NSString *fc3 = @"Franklins Business";

     [allfcContent addObject: fc1];
     [fc1 release];

     [allfcContent addObject: fc2];
     [fc2 release];

     [allfcContent addObject: fc3];
     [fc3 release];

     // PC
     NSMutableArray *allphContent = [[NSMutableArray alloc] init];

     NSString *ph1 = @"Changing Occupancy";
     NSString *ph2 = @"Sketches";
     NSString *ph3 = @"Servant House";
     NSString *ph4 = @"Monument";
     NSString *ph5 = @"Virtual Model";

     [allphContent addObject: ph1];
     [ph1 release];

     [allphContent addObject: ph2];
     [ph2 release];

     [allphContent addObject: ph3];
     [ph3 release];

     [allphContent addObject: ph4];
     [ph4 release];

     [allphContent addObject: ph5];
     [ph5 release];

     // Each content page's view

     //UIView *ccContent = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
     UIView *fcContent = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
     UIView *phContent = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];

     //ccContent.backgroundColor = [UIColor whiteColor];
     fcContent.backgroundColor = [UIColor whiteColor];
     phContent.backgroundColor = [UIColor whiteColor];

     //[ccContent addSubview:[SiteOneController myNavBar1:@"Constitution Center Content"]];
     [fcContent addSubview:[SiteOneController myNavBar1:@"Franklin Court Content"]];
     [phContent addSubview:[SiteOneController myNavBar1:@"Presidents House Content"]];   

     //allocate the view
     self.view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];

     //set the view's background color
     self.view.backgroundColor = [UIColor whiteColor];

     [self.view addSubview:[SiteOneController myNavBar1:@"Sites"]];

     NSMutableArray *sites = [[NSMutableArray alloc] init];

     NSString *one = @"Constution Center";
     NSString *two = @"Franklin Court";
     NSString *three = @"Presidents House";

     [sites addObject: one];
     [one release];

     [sites addObject: two];
     [two release];

     [sites addObject: three];
     [three release];

     NSString *ccName = @"Constitution Center";
     NSString *fcName = @"Franklin Court";

     NSString *element;
     int j = 0;
     for (element in sites)
     
         UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

         //setframe (where on screen)
         //separation is 15px past the width (45-30)
         button.frame = CGRectMake(a, b + (j*45), c, d);

         [button setTitle:element forState:UIControlStateNormal];

         button.backgroundColor = [SiteOneController myColor1];

         /*- (void) fooFirstInput:(NSString*) first secondInput:(NSString*) second 
             NSLog(@"Logs %@ then %@", first, second);
         
         - (void) performMethodsViaSelectors 
             [self performSelector:@selector(fooNoInputs)];
             [self performSelector:@selector(fooOneInput:) withObject:@"first"];
             [self performSelector;@selector(fooFirstInput:secondInput:) withObject:@"first" withObject:@"second"];*/

         //UIView *old = self.view;

         if (element == ccName) 
             [button addTarget:self action:@selector(showCCView)
              forControlEvents:UIControlEventTouchUpInside];
          
          else if (element == fcName) 
          
          else 
          

         [self.view addSubview: button];
         j++;
     

 

// This method show the content views for each of the sites.
/*+ (void) showCCView 
    self.view = [SiteOneController ccContent];
*/

【参考方案1】：

您正在尝试使用同一个 View 控制器实例来控制多个 View 对象，但这是行不通的。如果你想过渡到显示另一个视图，你应该使用另一个视图控制器来显示它，或者至少将新视图添加为窗口的子视图。