需求:点击textField或者textView,弹窗键盘,点击cell跳转到另外一个控制器时候,同时退出键盘,返回到上一级界面,键盘自动弹出
默认情况键盘是不会随着页面跳转而自动退出的,如图
实现的最终效果图,如下
实现步骤
- 1.给
UIViewController扩展分类文件UIViewController+Swizzling - 2.在
+ (void)load方法中,viewWillDisappear:和viewDidAppear:交换方法 - 3.在
swizzling_viewWillDisappear:中,拿到当前响应者View,使用objc_setAssociatedObject设置关联对象,并取消响应 - 4.在
swizzling_viewDidAppear拿到设置的关联对象,设置成第一响应
+ (void)load{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
swizzling_exchangeMethod([UIViewController class] ,@selector(viewDidAppear:), @selector(swizzling_viewDidAppear:));
swizzling_exchangeMethod([UIViewController class] ,@selector(viewWillDisappear:), @selector(swizzling_viewWillDisappear:));
});
}
// 注意这个key相当于NULL,仅仅一个key时候才可以这样使用,多个key不可以这样使用
static char UIFirstResponderViewAddress;
#pragma mark - ViewWillDisappear
- (void)swizzling_viewWillDisappear:(BOOL)animated{
[self swizzling_viewWillDisappear:animated];
UIView *view = (UIView *)[UIResponder currentFirstResponder];
if ([view isKindOfClass:[UIView class]] && view.viewController == self) {
objc_setAssociatedObject(self, &UIFirstResponderViewAddress, view, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
[view resignFirstResponder];
}else{
objc_setAssociatedObject(self, &UIFirstResponderViewAddress, nil, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
}
#pragma mark - ViewDidAppear
- (void)swizzling_viewDidAppear:(BOOL)animated{
[self swizzling_viewDidAppear:animated];
UIView *view = objc_getAssociatedObject(self, &UIFirstResponderViewAddress);
[view becomeFirstResponder];
}
