IOS控件系列--在任意视图上添加小红点

一、先上效果图：

二.将需要显示的控件作为这个小红点的父结点，需要注意的地方是，如果父结点与小红点需要进行精确的座标，那么需要进行座标系的转换，这里也提供了一个 例子

其他的没什么好分析的，直接给出源码吧：

//
//  RedPointBadgeView.h
//  IMobPay
//
//  Created by liuxiaobing on 2018/7/23.
//  Copyright © 2018 QTPay. All rights reserved.
//  小红点提示视图

#import 

typedef NS_ENUM(NSUInteger, Direction) {
    LEFT_TOP,
    LEFT_BOTTOM,
    RIGHT_TOP,
    RIGHT_BOTTOM
};

@interface RedPointBadgeView : UILabel

@property(nonatomic,assign) NSInteger redPointRadius;
@property(nonatomic,assign) CGFloat redPointWidth;
@property(nonatomic,assign) Direction curDirection;


/**
 显示小红点

 @param targetView : 目标视图
 @param count 小红点个数
 @param direction 在目标视图的方位
 */
-(void) showTargetView:(UIView*)targetView forCount:(NSInteger) count location:(Direction)direction;


/**
 显示小红点

 @param targetView 目标视图
 @param count 未读条数
 @param pos 显示的位置
 */
-(void) showTargetView:(UIView*)targetView forCount:(NSInteger) count position:(CGPoint) pos;

/**
 更新小红点

 @param targetView 目标视图
 @param count 标识数
 */
-(void) updateBadgeView:(UIView*)targetView forCount:(NSInteger)count;

/**
 隐藏小红点

 @param targetView 目标视图
 */
-(void) dissmiss:(UIView*)targetView;


@end

.m文件

//
//  RedPointBadgeView.m
//  IMobPay
//
//  Created by liuxiaobing on 2018/7/23.
//  Copyright © 2018 QTPay. All rights reserved.
//

#import "RedPointBadgeView.h"

static const int RED_POINT_TAG = 0x123;

@implementation RedPointBadgeView
-(void) showTargetView:(UIView*)targetView forCount:(NSInteger) count location:(Direction)direction{
    if(count <= 0 || !targetView) return;
    [self adjustSize:targetView forCount:count location:direction];
    [self buildAttr:targetView];
}

-(void) showTargetView:(UIView*)targetView forCount:(NSInteger) count position:(CGPoint) pos{
    if(count == 1 ){
        self.redPointRadius = 10;
        self.redPointWidth = self.redPointRadius;
        self.layer.cornerRadius = self.redPointRadius / 2;
    }
    else if(count > 1 && count <= 99){
        self.redPointRadius = 16;
        self.redPointWidth = self.redPointRadius;
        self.layer.cornerRadius = self.redPointRadius / 2;
        self.text = [NSString stringWithFormat:@"%ld",(long)count];
    }else{
        self.redPointRadius = 16;
        self.redPointWidth = self.redPointRadius * 1.5;
        self.layer.cornerRadius = self.redPointRadius / 2;
        self.text = @"99+";
    }
    CGPoint point = [targetView convertPoint:CGPointMake(pos.x,pos.y) toView:[targetView superview]];
    self.frame = CGRectMake(point.x,point.y,self.redPointWidth, self.redPointRadius);
    [self buildAttr:targetView];
}

-(void) buildAttr:(UIView*)targetView{
    self.textColor = [UIColor whiteColor];
    self.font = [UIFont systemFontOfSize:9];
    self.textAlignment = NSTextAlignmentCenter;
    self.backgroundColor = [UIColor redColor];
    self.tag = RED_POINT_TAG;
    self.layer.masksToBounds = YES;
    [targetView addSubview:self];
}

-(void)adjustSize:(UIView*)targetView forCount:(NSInteger)count location:(Direction)direction{
    self.curDirection = direction;
    if(count == 1 ){
        self.redPointRadius = 10;
        self.redPointWidth = self.redPointRadius;
        self.layer.cornerRadius = self.redPointRadius / 2;
    }
    else if(count > 1 && count <= 99){
        self.redPointRadius = 16;
        self.redPointWidth = self.redPointRadius;
        self.layer.cornerRadius = self.redPointRadius / 2;
        self.text = [NSString stringWithFormat:@"%ld",(long)count];
    }else{
        self.redPointRadius = 16;
        self.redPointWidth = self.redPointRadius * 1.5;
        self.layer.cornerRadius = self.redPointRadius / 2;
        self.text = @"99+";
    }

    switch(direction){
        case LEFT_TOP:
            self.frame = CGRectMake(-self.redPointRadius / 2,-self.redPointRadius / 2,
                                    self.redPointWidth, self.redPointRadius);
            break;

        case LEFT_BOTTOM:
            self.frame = CGRectMake(-self.redPointRadius / 2,targetView.frame.size.height - self.redPointRadius * 0.8,
                                    self.redPointWidth, self.redPointRadius);
            break;

        case RIGHT_TOP:
            self.frame = CGRectMake(targetView.frame.size.width - self.redPointWidth / 2, -self.redPointRadius / 2,
                                    self.redPointWidth, self.redPointRadius);
            break;

        case RIGHT_BOTTOM:
            self.frame = CGRectMake(targetView.frame.size.width - 0.8 * self.redPointRadius,
                                    targetView.frame.size.height - self.redPointRadius * 0.8,                                                     self.redPointWidth, self.redPointRadius);
            break;
    }
}

-(void) updateBadgeView:(UIView*)targetView forCount:(NSInteger)count{
    UIView *labelCount = [targetView viewWithTag:RED_POINT_TAG];
    if(labelCount){
        if(count < 1){
            [labelCount removeFromSuperview];
            return;
        }
        if(count == 1){
            self.text = @"";
        }
        [self adjustSize:targetView forCount:count location:self.curDirection];
    }

}

-(void) dissmiss:(UIView*)targetView{
    if(targetView && [targetView viewWithTag:RED_POINT_TAG]){
        [[targetView viewWithTag:RED_POINT_TAG] removeFromSuperview];
    }
}


@end

测试代码：

//
//  ViewController.m
//  RedPointBadgeView
//
//  Created by liuxiaobing on 2018/7/23.
//  Copyright © 2018 liuxiaobing. All rights reserved.
//

#import "ViewController.h"
#import "RedPointBadgeView.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.


    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(200, 100, 80, 80)];
    [button setTitle:@"test" forState:UIControlStateNormal];
    button.backgroundColor = [UIColor grayColor];
    [button addTarget:self action:@selector(onClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

    RedPointBadgeView *redPointView = [[RedPointBadgeView alloc] init];
    [redPointView showTargetView:button forCount:1 location:RIGHT_TOP];


    UIButton *right_bottom = [[UIButton alloc] initWithFrame:CGRectMake(200, 270, 80, 80)];
    [right_bottom setTitle:@"test" forState:UIControlStateNormal];
    right_bottom.backgroundColor = [UIColor grayColor];
    [right_bottom addTarget:self action:@selector(onClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:right_bottom];

    RedPointBadgeView *redPointView2 = [[RedPointBadgeView alloc] init];
    [redPointView2 showTargetView:right_bottom forCount:5 location:RIGHT_BOTTOM];


    UIButton *left_bottom = [[UIButton alloc] initWithFrame:CGRectMake(50, 270, 80, 80)];
    [left_bottom setTitle:@"test" forState:UIControlStateNormal];
    left_bottom.backgroundColor = [UIColor grayColor];
     [left_bottom addTarget:self action:@selector(onClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:left_bottom];

    RedPointBadgeView *redPointView3 = [[RedPointBadgeView alloc] init];
    [redPointView3 showTargetView:left_bottom forCount:25 location:LEFT_BOTTOM];


    UIButton *left_up = [[UIButton alloc] initWithFrame:CGRectMake(50, 100, 80, 80)];
    //[left_up setTitle:@"left_up" forState:UIControlStateNormal];
    UIImage *image = [UIImage imageNamed:@"shareview_weixin@2x"];
    [left_up setImage:image forState:UIControlStateNormal];
    left_up.backgroundColor = [UIColor grayColor];
     [left_up addTarget:self action:@selector(onClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:left_up];

    RedPointBadgeView *redPointView4 = [[RedPointBadgeView alloc] init];
    [redPointView4 showTargetView:left_up forCount:112 location:LEFT_TOP];

    RedPointBadgeView *redPointView5 = [[RedPointBadgeView alloc] init];
    CGPoint pos = CGPointMake([left_up imageView].frame.origin.x + 10, [left_up imageView].frame.origin.y - 10);
    [left_up imageView].clipsToBounds = NO;

    [redPointView5 showTargetView:[left_up imageView] forCount:45 position:pos];

}

-(void)onClick:(UIButton*)button{
    NSLog(@"65-------------");
    for (UIView *subView in button.subviews){
        if([subView isKindOfClass:[RedPointBadgeView class]]){
           // [(RedPointBadgeView *)subView dissmiss:button];
            [(RedPointBadgeView *)subView updateBadgeView:button forCount:1];
        }

    }
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


@end