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>
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.
