拦截复制,粘贴,在UIWebView中定义弹出窗口

Question

当我们在UIWebView中突出显示文本时,通常会出现复制,粘贴,定义等.我如何拦截这个,以便当我选择复制时,我会调用其他方法/做其他事情.这可能吗？

Answer 1

你可以简单地覆盖-copy:

- (void)copy:(id)sender
{
    // Do something else here
    return [super copy:sender];
}

编辑以回答您的评论.

定义有点棘手,因为它是私有的.但是,您可以实现自己的方法.使用所需的项目设置UIMenuController.

UIMenuItem *copyItem = [[UIMenuItem alloc] initWithTitle:@"Copy" 
                                                  action:@selector(myCopy:)];

UIMenuItem *defineItem = [[UIMenuItem alloc] initWithTitle:@"Define"
                                                    action:@selector(myDefine:)];

[[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObjects:defineItem, copyItem, nil]];
[defineItem release];
[copyItem release];

然后你实现这些方法.

至于define,它的方式会更复杂.首先,你需要通过重写-canPerformAction来检查UIReferenceLibraryController是否有定义:withSender:

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender 
{
    if (action == @selector(myDefine:)) {
        // Make sure we are on iOS5.x
        if (NSClassFromString(@"UIReferenceLibraryViewController")) {
            return [UIReferenceLibraryViewController dictionaryHasDefinitionForTerm:[webView selectedText]];
        }
    }
    // Implement other custom actions here
    return NO;
}

-selectedText在这里是UIWebView上的一个类别:

- (NSString *)selectedText {
    return [self stringByEvaluatingJavaScriptFromString:@"window.getSelection().toString()"];
}

然后你需要实现myDefine:

- (void)myDefine:(UIMenuController *)menuController 
{    
    CGRect selectedWordFrame = [webView rectForSelectedText];

    UIReferenceLibraryViewController *dict = [[UIReferenceLibraryViewController alloc] initWithTerm:[webView selectedText]];
    UIPopoverController *popover = [[UIPopoverController alloc] initWithContentViewController:dict];
    [popover presentPopoverFromRect:selectedWordFrame
                             inView:webView
           permittedArrowDirections:UIPopoverArrowDirectionAny
                           animated:YES];
    [popover setDelegate:self];
    [dict release];
}
- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController 
{
    [popoverController release];
}

编辑以再次回答您的评论

-rectForSelectedText是UIWebView上的另一个自定义类别.

- (CGRect)rectForSelectedText {
    return CGRectFromString([self stringByEvaluatingJavaScriptFromString:@"getRectForSelectedWord()"]);
}

它的作用是调用一个返回你可以使用CGRectFromString()转换的字符串的javascript,它看起来像这样:

function getRectForSelectedWord() {
    var selection = window.getSelection();
    var range = selection.getRangeAt(0);
    var rect = range.getBoundingClientRect();
    return "{{" + rect.left + "," + rect.top + "}, {" + rect.width + "," + rect.height + "}}";
}

查看此页面以了解如何将javascript注入UIWebView.