ios开发-新浪微博10-(下拉菜单的二次封装 完整版)

为了供大家的参考学习特意将每个知识点 分开列出

注意这里的封装

我们对下拉菜单的 大小 内容大小 位置 都进行了改进

可以传入个UI控件 也可以传入一个控制器

当下拉菜单弹出的时候 要遮盖一层 将菜单意外界面 事件屏蔽

当点击空白处 下拉菜单收回

这里用到了转换坐标系 这个知识点在后面也会讲解到

#import <UIKit/UIKit.h>

@interface QHDropdownMenu : UIView

+(instancetype)menu;

@property(nonatomic,strong)UIView *content;

@property(nonatomic,strong)UIViewController *contentController;
/**
*  显示
*/
-(void)showFrom:(UIView *)from;
/**
*  销毁
*/
-(void)dismiss;
@end

#import "QHDropdownMenu.h"

@interface QHDropdownMenu()
/**
*  将来用来显示具体内容的容器
*/

@property(nonatomic,strong)UIImageView *containerView;

@end

@implementation QHDropdownMenu
//懒加载一般用强指针
//除非先创建
-(UIImageView *)containerView
{
if (!_containerView) {

//添加一个灰色图片控件
UIImageView *containerView = [[UIImageView alloc]init];
containerView.image = [UIImage imageNamed:@"popover_background"];
//        containerView.width = 217;
//        containerView.height = 217;
containerView.userInteractionEnabled = YES;
[self addSubview:containerView];
self.containerView = containerView;
}
return _containerView;
}
-(id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
//清除颜色
self.backgroundColor = [UIColor clearColor];

//        //添加一个灰色图片控件
//        UIImageView *containerView = [[UIImageView alloc]init];
//        containerView.image = [UIImage imageNamed:@"popover_background"];
//        containerView.width = 217;
//        containerView.height = 217;
//        containerView.userInteractionEnabled = YES;
//        [self addSubview:containerView];
//        self.containerView = containerView;

}
return self;
}

+(instancetype)menu
{
return [[self alloc]init];
}

-(void)setContent:(UIView *)content
{
_content = content;

//调整内部位置
content.x = 10;
content.y = 15;

//设置内容的宽度
//    content.width = self.containerView.width - 2*content.x;

//设置灰色的高度
self.containerView.height = CGRectGetMaxY(content.frame)+11;

//设置灰色的宽度
self.containerView.width = CGRectGetMaxX(content.frame)+10;

//添加内容到灰色图片中
[self.containerView addSubview:content];
}

-(void)setContentController:(UIViewController *)contentController
{
_contentController = contentController;

self.content = contentController.view;
}
/**
*  显示
*/
-(void)showFrom:(UIView *)from
{
//1.获得最上面的窗口
UIWindow *window = [[UIApplication sharedApplication].windows lastObject];

//2.添加自己到窗口
[window addSubview:self];

//3.设置尺寸 创建出来都是全屏的
self.frame = window.bounds;

//4.调整灰色图片的位置
self.containerView.x = (self.width - self.containerView.width)*0.5;

//默认情况下，frame是父控件左上角坐标为原点
//转换坐标新

CGRect newFrame = [from convertRect:from.bounds toView:window];

self.containerView.centerX = CGRectGetMidX(newFrame);

self.containerView.y = CGRectGetMaxY(newFrame);

}
/**
*  销毁
*/
-(void)dismiss
{
[self removeFromSuperview];
}

/**
*  监听整个遮盖的面积
*
*  @param touches <#touches description#>
*  @param event   <#event description#>
*/
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self dismiss];
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/

@end