ios ~ UITextView实现点击富文本响应事件(用户协议、隐私政策等等)

UITextView实现点击富文本响应事件

前因：开发中常常会遇到点击富文本链接跳转的情况，最常碰到的是在注册的时候会有同意各种协议的文本，点击会跳转显示对应协议。

通过UITextView添加带有超链接的富文本，就可以在delegate的

- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange interaction:(UITextItemInteraction)interaction {

    NSLog(@"%@", URL);

    return YES;
}

监听到点击链接的事件。

这样就不用写两个button或者其他方式实现点击效果，方便快捷。

具体设置如下：

NSMutableAttributedString *mAttr = [[NSMutableAttributedString alloc] initWithString:@"点击“注册”即表示您同意"];
NSAttributedString *registPolicyAttr = [[NSAttributedString alloc] initWithString:@"《用户注册服务协议》" attributes:@{
    NSForegroundColorAttributeName: [UIColor colorWithRed:78/255.0 green:187/255.0 blue:192/255.0 alpha:1.0],
    NSLinkAttributeName: @"www.baidu.com"
}];
NSAttributedString *privacyPolicyAttr = [[NSAttributedString alloc] initWithString:@"&《用户隐私协议》" attributes:@{
    NSForegroundColorAttributeName: [UIColor colorWithRed:78/255.0 green:187/255.0 blue:192/255.0 alpha:1.0],
    NSLinkAttributeName: @"www.google.com"
}];

[mAttr appendAttributedString:registPolicyAttr];
[mAttr appendAttributedString:privacyPolicyAttr];

textView.attributedText = mAttr.copy;
textView.delegate = self;
textView.scrollEnabled = NO;
textView.editable = NO;

但是还有一些细节的地方需要调整一下。

UITextView的超链接一直是蓝色

这是因为UITextView自带了样式，我们只需要在设置textView.attributedText之前，把样式清空就行。

textView.linkTextAttributes = @{};

点击超链接的时候，会有底色为灰色的高亮显示

这种系统默认的实现，好像没有找到可以修改的地方（如果有希望大家在评论区告诉我）。只能用别的办法解决，幸好UITextView给我们提供了一个方法，可以根据点击的点获取最近区域的富文本状态，通过判断获取到的富文本是否包含超链接，来响应超链接事件。

- (void)handleTap:(UITapGestureRecognizer *)tap {
    UITextView *textView = (UITextView *)tap.view;
    CGPoint tapLocation = [tap locationInView:textView];
    UITextPosition *position = [textView closestPositionToPoint:tapLocation];
    NSDictionary *attr = [textView textStylingAtPosition:position inDirection:UITextStorageDirectionForward];
    if ([attr.allKeys containsObject:NSLinkAttributeName]) {
        NSLog(@"%@", attr[NSLinkAttributeName]);
    }
}

禁用文本选择和复制粘贴

为了让实现效果看起来更像点击了两个按钮，要取消掉UITextView的文本选择和复制粘贴功能。

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {
    return NO;
}

返回NO即可。

2、例子：

用户服务协议.png

- (void)viewDidLoad {

    _agreementTextView = [[UITextView alloc] init];
    _agreementTextView.text = @"我已阅读并同意《俄语阅读用户服务协议》";
    _agreementTextView.backgroundColor = [UIColor yellowColor];
    _agreementTextView.textColor = RGBA(142, 142, 142, 1);
    _agreementTextView.textAlignment = NSTextAlignmentCenter;
    _agreementTextView.textContainerInset = UIEdgeInsetsMake(0, 0, 0, 0);
    _agreementTextView.font = [UIFont systemFontOfSize:[UIScreen mainScreen].bounds.size.width/375*11 weight:UIFontWeightRegular];
    _agreementTextView.showsVerticalScrollIndicator = NO;
    _agreementTextView.scrollEnabled = NO;
    _agreementTextView.editable = NO;
    self.agreementTextView.delegate = self;
    [self.view addSubview:self.agreementTextView];
    [self.agreementTextView makeConstraints:^(MASConstraintMaker *make) { 
        make.centerX.equalTo(self.view);
        make.top.mas_equalTo(self.loginQuickBut.mas_bottom).offset([UIScreen mainScreen].bounds.size.width/375*28);
        make.width.mas_equalTo([UIScreen mainScreen].bounds.size.width/375*235);
        make.height.mas_equalTo([UIScreen mainScreen].bounds.size.width/375*13);
    }];
    [self agreementSetupHanle];
}

- (void)agreementSetupHanle {
    
    NSString *agreementMessage = self.agreementTextView.text;
    
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc]initWithString:agreementMessage];
    
    [attributedString addAttribute:NSLinkAttributeName
                             value:@"2"
                             range:[[attributedString string] rangeOfString:@"《俄语阅读用户服务协议》"]];
    [attributedString addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:[UIScreen mainScreen].bounds.size.width/375*11] range:[[attributedString string] rangeOfString:agreementMessage]];
    
    [attributedString addAttribute:NSForegroundColorAttributeName value:RGBA(142, 142, 142, 1) range:[[attributedString string] rangeOfString:agreementMessage]];
    self.agreementTextView.linkTextAttributes = @{ NSForegroundColorAttributeName: [UIColor colorWithRed:75.0/255.0 green:168.0/255.0 blue:161.0/255.0 alpha:1],
                                                  NSUnderlineColorAttributeName: [UIColor clearColor],
                                                  NSUnderlineStyleAttributeName: @(NSUnderlineStyleSingle)};

    // 设置间距
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.lineSpacing = 5;// 字体的行间距
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:[[attributedString string] rangeOfString:agreementMessage]];

    self.agreementTextView.attributedText = attributedString;
    
}

- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange interaction:(UITextItemInteraction)interaction {
    
    if ([URL.absoluteString  isEqualToString:@"2"]) {
        CheckUserAgreementCTRL *agreementVC = [[CheckUserAgreementCTRL alloc] init];
        agreementVC.originMark = 2;
        [self.navigationController pushViewController:agreementVC animated:YES];
        
    }
    return YES;
    
}

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {
    // 禁用文本复制、粘贴
    return NO;
}