健康资讯 1. 什么是blockUI?
BlockUI是一种在web开发中常用的JavaScript插件，主要用于在用户操作时阻止用户对页面的操作，即前端阻塞，常见的应用包括：
- 在AJAX请求期间阻止用户对页面的交互
- 在查看图片或者视音频等资源时，防止用户进行其他操作
- 等待某些功能或操作完成时，防止用户对页面进行不必要的操作
- 对于高级用户，可以在处理一些特殊需求时，防止用户在无意义的抢占资源
2. BlockUI如何实现?
BlockUI的实现思路比较简单，就是通过添加一个层在页面中，阻止用户对页面的交互，从而避免了页面因为用户的操作而出现弹窗等情况。实现方法包括：
1). 使用HTML和CSS创建一个层，将其添加到页面主体中，覆盖整个页面，阻止用户对页面进行任何操作。
2). 在该层中添加一些信息，提示用户当前页面正在加载或处理中，这有利于用户了解页面的状态。
3). 在AJAX请求完成后，移除该层，使用户重新能够对页面进行交互。
4). 提供一些可选配置项，例如层的颜色、位置、内容等。这些配置项有助于在特定的应用场景中提供更好的用户体验。
3. BlockUI的基本使用方法?
BlockUI的基本使用方法如下：
- 在HTML中引入BlockUI的相应文件：
```html
<link href=https://xitong.haoyundao.net/"/your/path/to/blockui.css\" rel=\"stylesheet\">
<script src=https://xitong.haoyundao.net/"/your/path/to/jquery.min.js\"></script>
<script src=https://xitong.haoyundao.net/"/your/path/to/jquery.blockui.js\"></script>
```
- 使用jquery插件定义一个最简单的blockUI：
```javascript
$.blockUI();
```
这将立即在页面上创建一个blockUI，它将覆盖整个主体，并阻止用户对整个页面进行任何操作。
- 等待response，消除BlockUI
```javascript
$.ajax({
type:'GET',
url:'your/path/to/server',
success:function(data) {
console.log(data);
},
error: function(error) {
console.log(error);
},
complete:function() {
$.unblockUI();
}
});
```
在AJAX请求的成功或失败后，取消BlockUI。
4. BlockUI的高级用法?
BlockUI的高级用法如下：
- 在BlockUI中添加消息：
```javascript
$.blockUI({
message: '请稍等，页面正在加载中……'
});
```
在BlockUI中添加一则消息，这个消息将出现在BlockUI的中心位置，默认情况下，该消息是一个Loading图标。
- 使用Timeout自动消除BlockUI：
```javascript
$.blockUI({ message: 'Processing...'});
setTimeout(function() { $.unblockUI(); }, 2000);
```
该功能对于页面的处理时间有限制。
- 在AJAX请求时防止用户的多次提交
```javascript
$('form.ajax').on('submit', function () {
var $this = $(this);
if ($this.data('submitted') === true) {
return false;
} else {
$this.parent().block({
message: '提交中，请稍后……'
});
$this.data('submitted', true);
}
});
```
使用此方法，避免用户对页面多次请求。
5. BlockUI中的常用配置项?
BlockUI中的常用配置项如下：
- message:定义在BlockUI中显示的消息
- css:定义BlockUI的CSS样式
- themedCSS:基于JQuery UI样式库创建BlockUI的CSS样式
- overlayCSS:定义覆盖页面的CSS样式
- cursorCss:定义在BlockUI中显示的鼠标指针
- fadeIn:定义BlockUI的FadeIn效果
- fadeOut:定义BlockUI的FadeOut效果
- timeout:自动消除BlockUI之前的等待时间
- centerY:定义BlockUI消息在纵向位置居中
- centerX:定义BlockUI消息在横向位置居中
- textAlign:定义BlockUI消息的文本对齐方式
- showOverlay:是否显示覆盖层
- onBlock:定义BlockUI出现时的功能
- onUnblock:定义BlockUI退出时的功能
6. BlockUI的优缺点?
BlockUI的优点：
- 开发简单：BlockUI的开发过程非常简单，只需几步即可完成基本设置。
- 可配置性强：BlockUI提供了很多高级用法，可以使开发者根据具体业务需要进行配置。
- 使用方便：BlockUI可以通过必要的javascript和CSS文件在页面中使用。
BlockUI的缺点：
- 对用户体验产生影响：为了防止一些可能的错误操作，BlockUI会阻止用户对页面的操作，在一定程度上影响了用户的体验。
- 动态加载的情况难以处理：在动态的页面加载中，BlockUI可能无法正常工作，导致一些意外情况的出现。
7. 总结
BlockUI作为一种前端阻塞的主要解决方案，可以通过覆盖层影响用户体验，在许多web开发项目中得到了广泛的应用。虽然它存在一定的不足，但是在适当的情况下，仍然是一种很好的前端解决方案。
1. What is blocking?
Blocking refers to the act of preventing someone from doing something or going somewhere by obstructing their path or denying them access. In the context of technology and the internet, blocking typically refers to the act of preventing someone from accessing certain websites, content or services.
There are various reasons why blocking might occur. For example, governments might block certain websites or services to prevent citizens from accessing information or opinions that are critical of the government or its policies. Companies might block certain websites or services to prevent employees from wasting time during working hours or to protect company assets from security threats.
2. Types of blocking
There are several types of blocking, each with its unique characteristics and purposes.
2.1. IP blocking
IP blocking is a type of blocking that works by preventing access to a website or service from a specific IP address or range of IP addresses. This type of blocking is commonly used by governments to restrict access to certain websites or services within their country. For example, China is known for its Great Firewall, which blocks access to many websites and services that are deemed politically sensitive or inappropriate.
2.2. DNS blocking
DNS blocking refers to the act of preventing access to a website or service by blocking its domain name system (DNS). This type of blocking typically involves adding the domain name to a blacklist, which prevents the DNS server from resolving the domain name to an IP address.
DNS blocking is commonly used by companies to prevent employees from accessing certain websites or services during working hours. It is also used by governments to restrict access to certain websites or services within their country.
2.3. Content blocking
Content blocking refers to the act of preventing access to specific content on a website or service. This type of blocking can be achieved in several ways, such as by blocking specific URLs, keywords or categories of content.
Content blocking is commonly used by companies to prevent employees from accessing inappropriate or distracting content during working hours. It is also used by parents to restrict their children's access to certain types of content online.
2.4. Port blocking
Port blocking refers to the act of preventing access to a website or service by blocking a specific network port that is used by that website or service. This type of blocking is commonly used by companies to prevent employees from using certain applications or services on the company network.
Port blocking is also used by internet service providers (ISPs) to prevent users from using certain types of services or protocols, such as peer-to-peer file sharing or virtual private networks (VPNs).
3. Pros and cons of blocking
Blocking has both advantages and disadvantages, depending on the context and purpose.
3.1. Pros
The main advantages of blocking include:
- Security: Blocking can help to protect against security threats by preventing access to malicious websites or services.
- Work productivity: Blocking can help to improve work productivity by preventing employees from accessing distracting or inappropriate content during working hours.
- Compliance: Blocking can help companies to comply with legal or regulatory requirements, such as data protection laws or industry standards.
- Content filtering: Blocking can help parents to protect children from inappropriate content online.
3.2. Cons
The main disadvantages of blocking include:
- Censorship: Blocking can be used to censor information or opinions that are deemed politically sensitive or inappropriate, thereby restricting freedom of speech and access to information.
- Overblocking: Blocking can result in overblocking, where legitimate content or services are also blocked due to false positives or errors in the blocking system.
- Circumvention: Blocking can be circumvented by using proxy servers, virtual private networks (VPNs), or other methods, which can undermine the effectiveness of the blocking system.
- Privacy: Blocking can infringe on privacy by monitoring or logging users' online activities to enforce the blocking system, which can raise issues of surveillance and data protection.
4. Conclusion
