Question

我有一个带有UIWebView控制器的视图控制器。我正在尝试在Web视图的html内容中获取javascript以将一些信息传递给我的目标c代码。我在网上遇到了一些在javascript函数中设置window.location的示例，然后通过将视图控制器设置为Web视图的委托并在shouldStartLoadWithRequest函数中捕获它来捕获生成的事件。不幸的是我无法让它工作，因为对我来说，即使我正在设置Web视图的委托，也不会调用shouldStartLoadWithRequest。

我的代码如下：

界面：

@interface StoryTextViewController : UIViewController <UIWebViewDelegate>
{
    IBOutlet UIWebView *storyWebView;   
    NSString *information;
}

@property (nonatomic, retain) IBOutlet UIWebView *storyWebView;
@property (nonatomic, retain) NSString *information;

@end

在界面中，* information变量由调用StoryTextViewController的上一个视图设置。

实施：

#import "StoryTextViewController.h"

@implementation StoryTextViewController

@synthesize storyWebView;
@synthesize information;

- (NSString *) contructHTMLText
{
    NSString *HTMLText = @"";

    NSArray *words = [information componentsSeparatedByString:@" "];
    NSString *header =
    @"<html>\n"
    "<head>\n"
    "<script type=\"text/javascript\">\n"

    "function marktext(theSpanID)\n"
    "{\n"
    "   var theSpan=document.getElementById(theSpanID);\n"
    "   if (theSpan.className == \"noHilite\")\n"
    "   {\n"
    "       theSpan.className = \"hilite\";\n"
    "       window.location = \"true\";\n"
    "   }\n"
    "   else\n"
    "   {\n"
    "       theSpan.className = \"noHilite\";\n"
    "       window.location = \"false\";\n"
    "   }\n"
    "}\n"

    "</script>\n"

    "<style type=\"text/css\">\n"

    ".hilite\n"
    "{\n"
    "   background-color:red;\n"
    "   color:white;\n"
    "   font: bold 60px arial,sans-serif\n"
    "}\n"

    ".noHilite\n"
    "{\n"
    "   background-color:white;\n"
    "   color:black;\n"
    "   font: 60px arial,sans-serif\n"
    "}\n"

    "</style>\n"

    "</head>\n"
    "<body>\n"
    "<div class=\"storyText\">\n";

    NSString *tailer = 
    @"</div>\n"
    "</body>\n"
    "</html>\n";

    HTMLText = [HTMLText stringByAppendingString:header];
    for (NSInteger i = 0; i < [words count]; i ++)
    {
        NSString *tag = [NSString stringWithFormat:@"   <span id=\"mytext%d\" class=\"noHilite\" onclick=\"marktext(\'mytext%d\')\">%@</span>&nbsp;\n", i, i, (NSString *)[words objectAtIndex:i]];
        HTMLText = [HTMLText stringByAppendingString:tag];
    }
    HTMLText = [HTMLText stringByAppendingString:tailer];
    NSLog(HTMLText);
    return HTMLText;
}

// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        storyWebView.delegate = self;
    }
    return self;
}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
    [super viewDidLoad];
    NSString *HTMLData = [self contructHTMLText];
    [storyWebView loadHTMLString:HTMLData baseURL:[NSURL URLWithString: @""]];  
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview
    // Release anything that's not essential, such as cached data
}

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

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType 
{   
    // handle event here    
    return true;
}

@end

发生的事情是，基本上，constructHTML函数接受* information变量中的文本并用文本中的每个单词包含一些html和javascript，这样无论何时单击一个单词，都会在其上应用css高亮度。我想要做的是计算高亮词的数量。我这样做是通过尝试传递函数，只要单击一个单词就调用该函数，但就像我说的那样，应该触发的shouldStartLoadWithRequest方法永远不会被执行。

我见过很多人做过这类事情，但我似乎无法弄清楚为什么它没有为我而战

Answer 1

您可以在设置委托

上设置断点

if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
    storyWebView.delegate = self;
}

我很确定storyWebView在那一刻是零。

您可以通过以下方式解决问题：

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSString *HTMLData = [self contructHTMLText];
    // empty statement
    // the trick is that if the view is not loaded from the .nib yet
    // it will be loaded and all connections established

    if (self.view);

    // here is setting delegate
    storyWebView.delegate = self;
    [storyWebView loadHTMLString:HTMLData baseURL:[NSURL URLWithString: @""]];  
}

Answer 2

您应该在viewDidLoad中设置委托，而不是initWithNibName:bundle:。或者，打开您的nib文件并从Web视图控制拖动到文件所有者，然后从下拉列表中选择“委托”。

Answer 3

window.location不应该是您要访问的目标网址的值吗？在marktext功能中，您将其设置为true或false。只有在收到URL请求并且即将到达某个地方时才会调用shouldStartLoadWithRequest。不确定将位置设置为布尔值是否足以触发导航事件。您可以将其设置为魔术URL，然后从shouldStartLoadWithRequest例程返回FALSE，如果它要求导航到该特定魔术URL并阻止它实际到达某个地方。然后可以允许有效的URL通过。
也可能想看看对this SO question的回复。 window.location可能存在一些时间问题。

Answer 4

我也看到了这个问题，因为我已经设置了

articleWeb.userInteractionEnabled = NO;`

你最好检查你的代码，设置

articleWeb.userInteractionEnabled = YES;`

我的iPhone应用程序中未调用shouldStartLoadWithRequest

4 个答案: