UIWebView with contentEditable (html editing), fir

问题:

I'm making an html editor component for an app (using UIWebView with contentEditable in iOS 5.0), and got stuck at how to handle UIWebView first responder status

[webView isFirstResponder], [webView becomeFirstResponder] and [webView resignFirstResponder] don't seem to work, and i've no idea how to make the webView become or resign it by code

If anyone knows how to work this out i would be very grateful, thanks in advance!

回答1:

Here is how I overwrite these methods in a UIWebView subclass (content is the id of the editable element):

-(BOOL)resignFirstResponder {
    [self setUserInteractionEnabled:NO];[self setUserInteractionEnabled:YES];
    return [super resignFirstResponder];
}

// only works on iOS 6+
-(void)becomeFirstResponder {
    self.keyboardDisplayRequiresUserAction = NO; // set here or during initialization  
    // important note: in some situations (newer iOS versions), it is also required to first call `blur()` on the 'content' element, otherwise the keyboard won't show up as expected
    [self stringByEvaluatingJavaScriptFromString:@"document.getElementById('content').focus()"];
}

-(BOOL)isFirstResponder{
    if ([[self stringByEvaluatingJavaScriptFromString:@"document.activeElement.id=='content'"] isEqualToString:@"true"]) {
        return YES;
    }
    else {
        return NO;
    }
}

isFirstResponder will only return true after the keyboard is shown (e.g, it will return false at UIKeyboardWillShowNotification)

In case this is an issue, another way to check if the UIWebView is the first responder is as follows:

+(BOOL)isFirstResponder:(UIView *)v{
    for (UIView *vs in v.subviews) {
        if ([vs isFirstResponder] || [self isFirstResponder:vs]) {
            return YES;
        }
    }
    return NO;
}
-(BOOL)isFirstResponder{
    return [[self class] isFirstResponder:self];
}

This way, the returned value will be YES even before/after the keyboard animation finishes (showing or hiding).

回答2:

I met the same problem recently, but solved it using pure JavaScript. Actually it doesn't need any Objective-C First Responder related methods. I just used the JavaScript to change the UIWebView's content - the targeting HTML element's contentEditable attribute value according to the requirement.

For example, using the following code to hide the Keyboard that called by the UIWebView's editable content:

[webView stringByEvaluatingJavaScriptFromString:@"document.getElementById('target').setAttribute('contentEditable','false')"];

Hope this is helpful. :)

回答3:

Here is how I overwrite these methods in a UIWebView subclass (content is the id of the editable element):

[_webView stringByEvaluatingJavaScriptFromString:@"document.getElementById('content').focus()"];

But Focus go to 1st point not last point

回答4:

Call the following lines of code when you want to hide the keyboard.

//wView is your UIWebView

NSString *webText = [wView stringByEvaluatingJavaScriptFromString:@"document.body.innerHTML"];
 [wView loadHTMLString:webText baseURL:nil];

回答5:

[webView loadHTMLString:[NSString stringWithFormat:@"%@", htmlString] baseURL:nil]; This works in iOS > 4