带有关闭按钮的alertView

灰太狼 2022-05-31 11:16 208阅读 0赞

# 概述 #

由于讨厌系统自带的alertView只能通过点击按钮才能关闭。你说万一按钮区域都是功能性的操作呢（这可不是我胡思乱想哦，要怪就产品的想法吧，呵呵哒），所以我们还是应该备有一个带有“X”（关闭按钮，为什么是叫X，因为X这个标志很明显嘛~）的alertView。

# 详细 #

#### 代码下载：[http://www.demodashi.com/demo/10917.html][http_www.demodashi.com_demo_10917.html] ####

#### 一、程序实现    ####

1、程序结构

![B949195B-257D-4F01-8F2B-243092F029DF.png][]

2、实现思路与代码

XBAlertView是作为显示弹出框的入口，在初始化XBAlertView示例时，会将弹出框除了按钮部分全都设置好。而按钮部分采用UICollectionView来实现（因为有可能有多个按钮，这样方便扩展）。

- (void)setupContentView{
        //title
        self.alertTitleLabel = [[UILabel alloc] init];
        self.alertTitleLabel.font = [UIFont boldSystemFontOfSize:17.0f];
        self.alertTitleLabel.textAlignment = NSTextAlignmentCenter;
        self.alertTitleLabel.frame = CGRectMake(TitleHorizontalOffset, TitleMarginTop, SelfWidth - TitleHorizontalOffset * 2, self.alertTitleLabel.font.lineHeight);
        [self addSubview:self.alertTitleLabel];
        
        //content
        CGFloat contentLabelWidth = SelfWidth - ContentHorizontalOffset * 2;
        CGFloat contentH = [self heightWithContent:_content byWidth:contentLabelWidth andFontSize:13 andLineSpacing:3];
        self.alertContentLabel = [[UILabel alloc] initWithFrame:CGRectMake(ContentHorizontalOffset, CGRectGetMaxY(self.alertTitleLabel.frame) + ContentMarginTop, contentLabelWidth, contentH)];
        self.alertContentLabel.numberOfLines = 0;
        self.alertContentLabel.textAlignment = NSTextAlignmentCenter;
        self.alertContentLabel.font = [UIFont systemFontOfSize:13.0f];
        [self addSubview:self.alertContentLabel];
        
        //self
        CGFloat selfHeight = TitleMarginTop + self.alertTitleLabel.font.lineHeight + ContentMarginTop + contentH + BtnMarginTop + kButtonHeight;
        CGFloat selfMarginLeft = (ScreenWidth - SelfWidth) / 2;
        self.frame = CGRectMake(selfMarginLeft, (ScreenHeight - selfHeight) / 2, SelfWidth, selfHeight);
        self.clipsToBounds = YES;
        self.layer.cornerRadius = 10.0;
        self.backgroundColor = [UIColor whiteColor];
        
        //collectionView
        [self addSubview:self.collectionView];
        _collectionView.delegate = self;
        _collectionView.dataSource = self;
        [_collectionView registerNib:[UINib nibWithNibName:@"XBAlertBtnCell" bundle:[NSBundle mainBundle]] forCellWithReuseIdentifier:btnCellOneID];
        [_collectionView registerNib:[UINib nibWithNibName:@"XBAlertBtnCellTwo" bundle:[NSBundle mainBundle]] forCellWithReuseIdentifier:btnCellTwoID];
        
        //X按钮
        UIButton *xButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [xButton setImage:[UIImage imageNamed:@"btn_close_normal.png"] forState:UIControlStateNormal];
        [xButton setImage:[UIImage imageNamed:@"btn_close_selected.png"] forState:UIControlStateHighlighted];
        xButton.frame = CGRectMake(self.frame.size.width - 32, 0, 32, 32);
        [self addSubview:xButton];
        [xButton addTarget:self action:@selector(dismissAlert) forControlEvents:UIControlEventTouchUpInside];
    }

为了能够切合原生方式的调用，提供了-(void)addAction:(dispatch\_block\_t)actionBlock withTitle:(NSString\*)title方法，该方法用于向XBAlertView添加按钮以及对应的响应block。

-(void)addAction:(dispatch_block_t)actionBlock withTitle:(NSString*)title{
        if(actionBlock && ![self isBlankString:title]){
            [self.blockArray addObject:actionBlock];
            [self.btnTitleArray addObject:title];
        }
    }

调用后会先保存到数组当中。

在这之后，调用方调用XBAlertView的show方法进行展示。

- (void)show
    {
        if(self.btnTitleArray.count == 0 || self.btnTitleArray.count > 2){
            //更新view的frame
            [self updateFrame];
        }
        [self.collectionView reloadData];
        UIViewController *topVC = [self appRootViewController];
        [topVC.view addSubview:self];
    }

show方法首先会根据两个数组是否有值来决定是否更新collectionView的frame。之后调用collectionView的reloadData，数据源就是这两个数组。这样加载后collectionView就有了需要展示的按钮。

然后获取\[UIApplication sharedApplication\].keyWindow.rootViewController，在这个控制器的view上添加上已经布局好的XBAlertView。

但是为了营造阴影效果，在XBAlertView被添加到父view之前，会调用以下方法创建一个遮罩层。这样就能达到显示的要求。

- (void)willMoveToSuperview:(UIView *)newSuperview
    {
        if (newSuperview == nil) {
            return;
        }
        UIViewController *topVC = [self appRootViewController];
    
        if (!self.backImageView) {
            self.backImageView = [[UIView alloc] initWithFrame:topVC.view.bounds];
            self.backImageView.backgroundColor = [UIColor blackColor];
            self.backImageView.alpha = 0.6f;
            self.backImageView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
        }
        [topVC.view addSubview:self.backImageView];
        CGRect afterFrame = CGRectMake((CGRectGetWidth(topVC.view.bounds) - self.frame.size.width) * 0.5, (CGRectGetHeight(topVC.view.bounds) - self.frame.size.height) * 0.5, self.frame.size.width, self.frame.size.height);
        self.frame = afterFrame;
        [super willMoveToSuperview:newSuperview];
    }

那么接下来就是点击响应了，因为每个按钮就是collectionView的一个cell，所以按钮的点击就转为了cell的didSelectItemAtIndexPath方法。在该方法中根据索引从前面保存好的数组取出相对应的block，并调用

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
        dispatch_block_t block = self.blockArray[indexPath.row];
        block();
        [self dismissAlert];
    }

那么为了将隐藏弹出框封装到里面，会主动调用dismissAlert方法隐藏弹出框。

#### 二、运行效果 ####

下载解压后，直接用xcode打开，即可运行

![4191AA2D-B0B8-4879-95E0-EF8016871A7B.png][]

![19815664-01D6-4B66-896F-042BD5977F36.png][]

![77C09C15-0105-4067-A237-CEACCD03CEFB.png][]

#### 代码下载：[http://www.demodashi.com/demo/10917.html][http_www.demodashi.com_demo_10917.html] ####

#### 注：本文著作权归作者，由demo大师发表，拒绝转载，转载需要作者授权 ####

[http_www.demodashi.com_demo_10917.html]: http://www.demodashi.com/demo/10917.html
[B949195B-257D-4F01-8F2B-243092F029DF.png]: /images/20220531/cd1b578e00294f1cb11ff68d5b58c9e4.png
[4191AA2D-B0B8-4879-95E0-EF8016871A7B.png]: /images/20220531/27c18f3a4df04291bd79dddd251318fa.png
[19815664-01D6-4B66-896F-042BD5977F36.png]: /images/20220531/9f3ce47cd7864051815f20090b7944d4.png
[77C09C15-0105-4067-A237-CEACCD03CEFB.png]: /images/20220531/cb9f7ef585384c4da50283364a51d9dd.png