我有一个带有 UIWebView Controller 的 View Controller 。我试图在 web View 的 html 内容中获取 javascript，以将一些信息传递给我的 objective-c 代码。我在网上遇到了一些在 javascript 函数中设置 window.location 的示例，然后捕获通过将 View Controller 设置为 Web View 的委托(delegate)并在 shouldStartLoadWithRequest 函数中捕获它而生成的事件。不幸的是我无法让它工作，因为对我来说 shouldStartLoadWithRequest 从未被调用，即使我正在设置 web View 的委托(delegate)。
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 的前一个 View 设置。
实现:
#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> \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
基本上，constructHTML 函数获取 *information 变量中的文本，并用一些 html 和 javascript 包装文本中的每个单词，这样每当单击一个单词时，就会在其上应用 css 高亮显示。我想做的是统计高亮单词的数量。我通过尝试在单击单词时调用的函数中传递一些内容来做到这一点，但就像我说的那样，永远不会执行应该被触发的 shouldStartLoadWithRequest 方法。
我见过很多人做这种事，但我似乎无法弄清楚为什么它不适合我
最佳答案
您可以在设置委托(delegate)上放置断点
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
storyWebView.delegate = self;
}
我很确定那一刻 storyWebView 为 nil。
您可以通过这种方式修复它:
- (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: @""]];
}
关于javascript - shouldStartLoadWithRequest 未在我的 iPhone 应用程序中调用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1076609/