Introduction to the tag in html and how to disable it

Definition and usage

tag is used to collect user information.
According to different type attribute values, the input field has many forms. Input fields can be text fields, checkboxes, masked text controls, radio buttons, buttons, etc.
Differences between HTML and XHTML
In HTML, the tag does not have a closing tag.
In XHTML, the tag must be closed correctly.
Example
A simple HTML form contains two text input boxes and a submit button:

 
<form action="form_action.asp" method="get">  
  First name: <input type="text" name="fname" />  
  Last name: <input type="text" name="lname" />  
  <input type="submit" value="Submit" />  
</form>

The disabled attribute specifies that the input element should be disabled.
Disabled input elements are neither available nor clickable. The disabled attribute can be set until some other condition is met (such as a checkbox being selected, etc.). Then, you need to use JavaScript to remove the disabled value and switch the value of the input element to available.

The following three writing methods can disable input

<input type="text" disabled="disabled" value="已禁用" />  
<input type="text" disabled="disabled" value="已禁用" />  
<input type="text" disabled="disabled" value="已禁用" />

The disabled input is grayed out by default, and the style can be modified through CSS. Note: IE9 and below cannot change the font color
1. Use CSS3 :disabled pseudo-element definition

CSS Code复制内容到剪贴板
//Chrome Firefox Opera Safari   
input:disabled{   
    border: 1px solid #DDD;   
    background-color: #F5F5F5;   
    color:#ACA899;   
}

2. Use attribute selector definition

CSS Code复制内容到剪贴板
//IE6 failed   
input[disabled]{   
    border: 1px solid #DDD;   
    background-color: #F5F5F5;   
    color:#ACA899;   
}

3. Use class to define and add a class

CSS Code复制内容到剪贴板
input.disabled{   
    border: 1px solid #DDD;   
    background-color: #F5F5F5;   
    color:#ACA899;   
}

Final result:

CSS Code复制内容到剪贴板
//Chrome Firefox Opera Safari IE9+   
input:disabled{   
    border: 1px solid #DDD;   
    background-color: #F5F5F5;   
    color:#ACA899;   
}   
//IE8-   
input[disabled]{   
    border: 1px solid #DDD;   
    background-color: #F5F5F5;   
    color:#ACA899;   
}   
//IE6 Using Javascript to add CSS class "disabled"  
* html input.disabled{   
    border: 1px solid #DDD;   
    background-color: #F5F5F5;   
    color:#ACA899;   
}

Note: IE8 bug
Because IE8 does not recognize:disabled, the input[disabled] and input:disabled styles become invalid. You can consider writing them separately, or use input[disabled] directly. ;The font color cannot be changed in IE9 and below.

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