ios – UIWebView Bug: – [UIWebView cut:]:无法识别的选择器发送到实例

在UIWebView中,如果包含文本的输入元素具有焦点,并且按下一个导致输入失焦的按钮,则随后双击输入以重新获得焦点,然后从弹出式栏中选择“剪切(或复制或粘贴)”这样会导致UIWebView崩溃与错误:
-[UIWebView cut:]: unrecognized selector sent to instance 0x10900ca60

演示项目:https://github.com/guarani/WebViewDoubleTapTestTests.git

我觉得这一定是UIWebView的bug,有什么想法吗?

为了完整,这里是我的网页视图的内容,

<html>
    <head>
    </head>
    <body>
        <br><br>
        <input type="text">
        <input type="button">
    </body>
</html>

在Apple提交了一个错误报告:15894403

更新2014/10/15:Bug仍然存在于iOS 8.0.2(12A405)

解决方法

这是一个苹果bug.问题是剪切:操作在响应者链中发送不正确,最终被发送到UIWebView实例,而不是实现该方法的内部UIWebDocumentView.

直到Apple修复了这个bug,让我们来看看Objective C的运行时间.

在这里,我将UIWebView子类化,以支持所有的UIResponderStandardEditActions方法,将它们转发到正确的内部实例.

@import ObjectiveC;    

@interface CutCopyPasteFixedWebView : UIWebView @end

@implementation CutCopyPasteFixedWebView

- (UIView*)_internalView
{
    UIView* internalView = objc_getAssociatedObject(self,"__internal_view_key");

    if(internalView == nil && self.subviews.count > 0)
    {
        for (UIView* view in self.scrollView.subviews) {
            if([view.class.description hasPrefix:@"UIWeb"])
            {
                internalView = view;

                objc_setAssociatedObject(self,"__internal_view_key",view,OBJC_ASSOCIATION_ASSIGN);

                break;
            }
        }
    }

    return internalView;
}

void webView_implement_UIResponderStandardEditActions(id self,SEL selector,id param)
{
    void (*method)(id,SEL,id) = (void(*)(id,id))[[self _internalView] methodForSelector:selector];

    //Call internal implementation.
    method([self _internalView],selector,param);
}

- (void)_prepareForNoCrashes
{
    NSArray* selectors = @[@"cut:",@"copy:",@"paste:",@"select:",@"selectAll:",@"delete:",@"makeTextWritingDirectionLeftToRight:",@"makeTextWritingDirectionRightToLeft:",@"toggleBoldface:",@"toggleItalics:",@"toggleUnderline:",@"increaseSize:",@"decreaseSize:"];

    for (NSString* selName in selectors)
    {
        SEL selector = NSSelectorFromString(selName);

        //This is safe,the method will fail if there is already an implementation.
        class_addMethod(self.class,(IMP)webView_implement_UIResponderStandardEditActions,"");
    }
}

- (void)awakeFromNib
{
    [self _prepareForNoCrashes];

    [super awakeFromNib];
}

@end

在你的故事板中使用这个子类.

玩的开心.

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