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判断视图是否相交以及是否被键盘遮盖

@interface UIView (Util)///返回视图是否相交，若相交，offset 的值表示避免相交需要的位移- (BOOL)isCoveredByView:(UIView *)view offset:(CGFloat *)offset;///返回视图是否被键盘遮盖，若是，offset 的值表示视图要避免遮盖的位移量- (BOOL)isCoveredByBoard:(CGRect)keyboardRect offset:(CGFloat *)offset;@end

@implementation UIView (Util)#pragma mark 判断当前视图是否被其他视图遮盖- (BOOL)isCoveredByView:(UIView *)view offset:(CGFloat *)offset {    if (!self || !view) {        return NO;    }    if (![self superview]) {        return NO;    }    if (self.hidden || view.hidden) {        return NO;    }    UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];    CGRect viewRect;    if([view isKindOfClass:[UIWindow class]]){        viewRect = [(UIWindow*)view convertRect:view.frame toWindow:keyWindow];    }else {        viewRect = [view.superview convertRect:view.frame toView:keyWindow];    }    CGRect rect = [self.superview convertRect:self.frame toView:keyWindow];    if (CGRectIsEmpty(rect) || CGRectIsNull(rect) || CGSizeEqualToSize(rect.size, CGSizeZero)) {        return NO;    }    CGFloat heightOfCovered = viewRect.origin.y - rect.origin.y - rect.size.height;    heightOfCovered = heightOfCovered > -viewRect.size.height ? heightOfCovered : -viewRect.size.height;    *offset = heightOfCovered;    return CGRectIntersectsRect(rect, viewRect);}#pragma mark 判断当前视图是否被键盘遮盖- (BOOL)isCoveredByBoard:(CGRect)keyboardRect offset:(CGFloat *)offset {    if (!self) {        return NO;    }    if (![self superview]) {        return NO;    }    if (self.hidden) {        return NO;    }    UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];    NSArray *windows = [[UIApplication sharedApplication] windows];    UIWindow *keyboardWindow;    for (id window in windows) {        NSString *keyboardWindowString = NSStringFromClass([window class]);        if ([keyboardWindowString isEqualToString:@"UITextEffectsWindow"]) {            keyboardWindow = window;            break;        }    }    if (keyboardWindow == nil) return NO;    keyboardRect = [keyboardWindow convertRect:keyboardRect toWindow:keyWindow];    CGRect rect = [self.superview convertRect:self.frame toView:keyWindow];    if (CGRectIsEmpty(rect) || CGRectIsNull(rect) || CGSizeEqualToSize(rect.size, CGSizeZero)) {        return NO;    }    CGFloat heightOfCovered = keyboardRect.origin.y - rect.origin.y - rect.size.height;    heightOfCovered = heightOfCovered > -keyboardRect.size.height ? heightOfCovered : -keyboardRect.size.height;    *offset = heightOfCovered;    return CGRectIntersectsRect(rect, keyboardRect);}@end

#pragma mark - 键盘显示- (void)keyboardWillShow:(NSNotification *)notification{    if ([self.textField isFirstResponder]) {        CGRect keyboardFrame = [[notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];        CGFloat offset;        if ([self.textField isCoveredByBoard:keyboardFrame offset:&offset]){            CGRect rect = self.textField.frame;            rect.origin.y += offset;            self.textField.frame = rect;        }    }}

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