将 UITextView 值从父视图控制器传递到 ModalViewController

Question

我一直在为 iPad 开发校报应用程序。我终于能够解析我需要的文章了。我使用 UITextView 将每篇文章的摘要放在父视图控制器上。现在我想做的是当按下 UITextView 顶部的自定义按钮时使用 ModalViewController 显示每篇文章。我在 StackOverFlow 中查看了几个 QA，但无法使我的项目正常运行。我将把一些代码放在这里，并将一些日志放在控制台上。任何帮助将不胜感激。提前致谢。

在我的 ArticleViewController.h （与 ModalViewController.h 相同）

@interface ArticleViewController : UIViewController {

    IBOutlet UIButton *doneReadingButton;
    IBOutlet UITextView *articleTextView;
}

@property (nonatomic, retain) UIButton *doneReadingButton;
@property (nonatomic, retain) UITextView *articleTextView;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil withText:(NSString *)text;

-(IBAction)doneReadingArticle:(id)sender;
//-(IBAction)displayArticleView:(id)sender;

@end

在我的 ArticleViewController.m （与 ModalViewController.m 相同）

#import "ArticleViewController.h"


@implementation ArticleViewController

@synthesize doneReadingButton;
@synthesize articleTextView;

- (IBAction)doneReadingArticle:(id)sender {
    [self dismissModalViewControllerAnimated:YES];
}

//This is where I need to display main article in modal view
/*
- (IBAction)displayArticleView:(id)sender {
[self presentModalViewController:articleTextView animated:YES];
}
*/



 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil withText:(NSString *)text {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];  
    if (self) {
        // Custom initialization.
        //self.articleTextView = [[UITextView alloc] init];
        //self.articleTextView.text = [text retain];
        self.articleTextView.text = text;
    }

    NSLog(@"********text in modal init******** >> %@",articleTextView.text);
    return self;
}



   // Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    //I guess, this is where I have to load main article
    self.articleTextView.text = @"This is a test!";

    NSLog(@"********text in modal******** >> %@",articleTextView.text);
}

在我的父视图控制器

-(IBAction)articleView04:(id)sender{
    storyView04 = [[ArticleViewController alloc] initWithNibName:@"ArticleViewController" bundle:[NSBundle mainBundle]];

    storyView04.articleTextView.text =[NSString stringWithString:@"TESTING! TESTING!"];
    [storyView04 setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
    storyView04.modalPresentationStyle = UIModalPresentationPageSheet;
    [self presentModalViewController:storyView04 animated:YES];
    [storyView04 release];
}

中所以，在控制台中，我只是得到这个，这只是一个占位符文本。

 2011-05-28 15:44:00.071 TheCalAggie[4179:207] ********text in modal******** >> This is a test!

我知道我必须将文本值从父视图传递到 ModalViewController，但我不确定是否正确传递它。我的代码一开始有意义吗？

无论如何。请帮助我完成这个项目。我真的必须在一周内完成它。再次感谢。

Answer 1

这是我要做的（取自我当前的项目）：

#import <UIKit/UIKit.h>


@interface DictionaryViewController : UIViewController {
    NSString *word;
    NSString *definition;
    IBOutlet UIWebView *webView;
    IBOutlet UINavigationItem *navItem;
}

@property(nonatomic, copy) NSString *word;
@property(nonatomic, copy) NSString *definition;
@property(nonatomic, retain) IBOutlet  UIWebView *webView;
@property(nonatomic, retain) IBOutlet UINavigationItem *navItem;

-(IBAction) done;
-(IBAction) pronounce;

@end

这是实现：

#import "DictionaryViewController.h"
#import "TBXML.h"
#import "Lexicontext.h"
#import "Lexicontext+Pronounce.h"

@implementation DictionaryViewController

@synthesize word, definition, webView, navItem;

-(void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"word"])
    {
        definition = [[Lexicontext sharedDictionary] definitionAsHTMLFor:word];
        [[self webView] loadHTMLString:definition baseURL:nil];
        navItem.title = word;
    }
}

-(void) done
{
    [self dismissModalViewControllerAnimated:YES];
}

-(void) pronounce
{
    [[Lexicontext sharedDictionary] pronounce:word];
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
        [self addObserver:self forKeyPath:@"word" options:0 context:nil];
    }
    return self;
}

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

- (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.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    [[self webView] loadHTMLString:definition baseURL:nil];
    navItem.title = word;

    UIScrollView *scrollview = [[webView subviews] objectAtIndex:0];
    scrollview.bounces = NO;
}

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

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

@end

您将如何使用它：

-(void) somethingHappened:(id) sender
{
     DictionaryViewController *dvc = [[DictionaryViewController alloc] initWithNibName:@"DictionaryViewController" bundle:[NSBundle mainBundle]];
     dvc.word = @"Some word to look up";
     [self presentModalViewController:dvc];
     [dvc release];
}

Answer 2

我猜您已经使用 IB 来创建视图。在这种情况下 [[[ArticleViewController alloc] init] autorelease]; 不会为您加载该界面。您必须使用 [[ArticleViewController alloc] initWithNibName:@"ArticleViewController" bundle:nil withText:@"Test!!"]; 才能获得所需的结果。

但是，您实现初始化程序的方式有些不正确。

self.articleTextView = [[UITextView alloc] init];
self.articleTextView.text = [text retain]; 

首先，XIB 将创建文本视图并链接到 articleTextView 属性。所以不需要再次创建它。此外，该视图尚未作为子视图添加到控制器的 view 属性中，因此它不会出现在屏幕上。 IB 创建的文本视图将保留在屏幕上，但没有参考。您应该删除第一行。其次，文本视图中的 text 属性是一个 copied 属性。所以你的保留可以被认为是泄漏。

self.articleTextView.text = text;

其他一切似乎都还好。

编辑

-(IBAction)showArticleView:(UIButton *)sender{
    storyView = [[ArticleViewController alloc] initWithNibName:@"ArticleViewController" bundle:[NSBundle mainBundle]];

    storyView.articleTextView.text = [articles objectAtIndex:[sender tag]];
    [storyView setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
    storyView.modalPresentationStyle = UIModalPresentationPageSheet;
    [self presentModalViewController:storyView animated:YES];
    [storyView release];
}

Answer 3

您的属性articleTextView正在获取字符串“TESTING！TESTING！”。如果您在屏幕上的 UITextview 上看不到它，那是因为您将其连接到具有相同名称的实例变量 (articleTextView)。您可能想要从实例变量中删除 IBOutlet 并将其放在属性上。 @property（非原子，保留）IBOutlet UITextView *articleTextView;您可能不需要再次连接它。希望这能消除您对 ivars 和属性之间可能存在的误解。