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滚动时自动显示与隐藏导航条定制
// // AMScrollingNavbarViewController.h // AMScrollingNavbar // // Created by Andrea on 08/11/13. // Copyright (c) 2013 Andrea Mazzini. All rights reserved. // #import <UIKit/UIKit.h> /*! * @name HYBScrollRenderController * @brief 在滚动视图向上滚动时，慢慢隐藏导航条或者向下滚动时，慢慢显示导航条，支持6.0以上版本系统。 * 在任何需要使用此功能的控制器类中，只要直接继承于此HYBScrollRenderController类，并在 * 创建滚动视图的时候，调用-followScrollView:方法来设置即可。 * @note 如果此类需要继承更多的特性，可直接修改继承的父类为自定义的控制器类。也可以把此类作为所有 * 类的基础父类，在继承此类的基础上，扩展所有基础属性。如HYBSuperBaseController : HYBScrollRenderController * @author huangyibiao */ @interface HYBScrollRenderController : UIViewController /*! * @brief 允许滚动的视图，支付UIScrollView、UITableView、UIWebView * @param scrollableView 可滚动的视图 */ - (void)followScrollView:(UIView *)scrollableView; @end
//
// AMScrollingNavbarViewController.m
// AMScrollingNavbar
//
// Created by Andrea on 08/11/13.
// Copyright (c) 2013 Andrea Mazzini. All rights reserved.
//
#import "HYBScrollRenderController.h"
@interface HYBScrollRenderController () <UIGestureRecognizerDelegate>
@property (nonatomic, weak) UIView *scrollableView;
@property (assign, nonatomic) float lastContentOffset;
@property (strong, nonatomic) UIPanGestureRecognizer *panGesture;
@property (strong, nonatomic) UIView *overlay;
@property (assign, nonatomic) BOOL isCollapsed;
@property (assign, nonatomic) BOOL isExpanded;
@end
@implementation HYBScrollRenderController
- (void)followScrollView:(UIView *)scrollableView {
self.scrollableView = scrollableView;
self.panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];
[self.panGesture setMaximumNumberOfTouches:1];
[self.panGesture setDelegate:self];
[self.scrollableView addGestureRecognizer:self.panGesture];
/* The navbar fadeout is achieved using an overlay view with the same barTintColor.
this might be improved by adjusting the alpha component of every navbar child */
CGRect frame = self.navigationController.navigationBar.frame;
frame.origin = CGPointZero;
self.overlay = [[UIView alloc] initWithFrame:frame];
if ([self isIOS7]) {
if (self.navigationController.navigationBar.barTintColor) {
[self.overlay setBackgroundColor:self.navigationController.navigationBar.barTintColor];
}
}
[self.overlay setUserInteractionEnabled:NO];
[self.navigationController.navigationBar addSubview:self.overlay];
[self.overlay setAlpha:0];
return;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
- (void)handlePan:(UIPanGestureRecognizer*)gesture {
CGPoint translation = [gesture translationInView:[self.scrollableView superview]];
float delta = self.lastContentOffset - translation.y;
self.lastContentOffset = translation.y;
CGRect frame;
if (delta > 0) {
if (self.isCollapsed) {
return;
}
frame = self.navigationController.navigationBar.frame;
if (frame.origin.y - delta < -24) {
delta = frame.origin.y + 24;
}
frame.origin.y = MAX(-24, frame.origin.y - delta);
self.navigationController.navigationBar.frame = frame;
if (frame.origin.y == -24) {
self.isCollapsed = YES;
self.isExpanded = NO;
}
[self updateSizingWithDelta:delta];
// Keeps the view's scroll position steady until the navbar is gone
if ([self.scrollableView isKindOfClass:[UIScrollView class]]) {
UIScrollView *scrollView = (UIScrollView *)self.scrollableView;
[scrollView setContentOffset:CGPointMake(scrollView.contentOffset.x,
scrollView.contentOffset.y - delta)];
}
}
if (delta < 0) {
if (self.isExpanded) {
return;
}
frame = self.navigationController.navigationBar.frame;
if (frame.origin.y - delta > 20) {
delta = frame.origin.y - 20;
}
frame.origin.y = MIN(20, frame.origin.y - delta);
self.navigationController.navigationBar.frame = frame;
if (frame.origin.y == 20) {
self.isExpanded = YES;
self.isCollapsed = NO;
}
[self updateSizingWithDelta:delta];
}
if ([gesture state] == UIGestureRecognizerStateEnded) {
self.lastContentOffset = 0;
[self checkForPartialScroll];
}
return;
}
- (void)checkForPartialScroll {
CGFloat pos = self.navigationController.navigationBar.frame.origin.y;
// Get back down
if (pos >= -2) {
[UIView animateWithDuration:0.2 animations:^{
CGRect frame;
frame = self.navigationController.navigationBar.frame;
CGFloat delta = frame.origin.y - 20;
frame.origin.y = MIN(20, frame.origin.y - delta);
self.navigationController.navigationBar.frame = frame;
self.isExpanded = YES;
self.isCollapsed = NO;
[self updateSizingWithDelta:delta];
}];
} else {
// And back up
[UIView animateWithDuration:0.2 animations:^{
CGRect frame;
frame = self.navigationController.navigationBar.frame;
CGFloat delta = frame.origin.y + 24;
frame.origin.y = MAX(-24, frame.origin.y - delta);
self.navigationController.navigationBar.frame = frame;
self.isExpanded = NO;
self.isCollapsed = YES;
[self updateSizingWithDelta:delta];
}];
}
return;
}
- (void)updateSizingWithDelta:(CGFloat)delta {
CGRect frame = self.navigationController.navigationBar.frame;
float alpha = (frame.origin.y + 24) / frame.size.height;
[self.overlay setAlpha:1 - alpha];
self.navigationController.navigationBar.tintColor = [self.navigationController.navigationBar.tintColor
colorWithAlphaComponent:alpha];
frame = self.scrollableView.superview.frame;
frame.origin.y = self.navigationController.navigationBar.frame.origin.y;
frame.origin.y += self.navigationController.navigationBar.frame.size.height;
// 判断是否是ios7及其以上版本
if (![self isIOS7]) {
frame.origin.y = self.navigationController.navigationBar.frame.origin.y - 20;
}
frame.size.height = frame.size.height + delta;
self.scrollableView.superview.frame = frame;
// Changing the layer's frame avoids UIWebView's glitchiness
frame = self.scrollableView.layer.frame;
frame.size.height += delta;
self.scrollableView.layer.frame = frame;
return;
}
- (BOOL)isIOS7 {
return ([UIDevice currentDevice].systemVersion.integerValue >= 7) ? YES : NO;
}
@end
最后更新：2017-04-03 05:39:53