分类 技术 下的文章

转自:https://www.zzxworld.com/posts/gdm-4k-hidpi-scale-setting

使用Gnome桌面环境是Linux系统下比较省事的选择,搭配它的登陆界面软件是GDM。在使用4K显示器时,我通常会把Gnome桌面的缩放设置为200%,这样看起来眼睛不会太累。但每次开机时会发现GDM登陆界面并没有使用这个缩放值,还是按100%无缩放的效果显示的。我希望登陆界面也能使用和桌面一样的缩放值。

我使用的是Arch Linux,在设置好显示器的显示效果后,会在当前用户$HOME/.config目录下生成一个monitors.xml配置文件。把这个文件复制到/var/lib/gdm/.config目录:

cp ~/.config/monitors.xml /var/lib/gdm/.config/

然后设置文件的所属用户和用户组:

chown gdm:gdm /var/lib/gdm/.config/monitors.xml

重启系统,会发现登录界面也和桌面一样,使用2倍的缩放来显示了。

联想电脑刷bios后主机型号和编码不见了,怎么办?下载对应的bios,运行解压,使用管理者权限打开cmd,切换到bios解压的目录,运行wflash2.exe 查看命令选项:

wflash2.exe /?
/mtm:nnnnnnn       Update system Machine Type and Model
/sn:nnnnnnn        Update system Serial Number

在机箱上找到型号:nnnnnn和主机编码:xxxxxxx,运行下列命令

wflash2.exe /mtm:nnnnnnn /sn:xxxxxxx

The <form> element is a container for different types of input elements, such as: text fields, checkboxes, radio buttons, submit buttons, etc.

All the different form elements are covered in this chapter: HTML Form Elements.

The <input>Element

The HTML <input> element is the most used form element.

An <input> element can be displayed in many ways, depending on the type attribute.

Here are some examples:

Type Description
<input type="text"> Displays a single-line text input field
<input type="radio"> Displays a radio button (for selecting one of many choices)
<input type="checkbox"> Displays a checkbox (for selecting zero or more of many choices)
<input type="submit"> Displays a submit button (for submitting the form)
<input type="button"> Displays a clickable button

Text Fields

The <input type="text"> defines a single-line input field for text input.

示例

A form with input fields for text:

<form>
  <label for="fname">First name:</label><br>
  <input type="text" id="fname" name="fname"><br>
  <label for="lname">Last name:</label><br>
  <input type="text" id="lname" name="lname">
</form>

效果

This is how the HTML code above will be displayed in a browser:




Note: The form itself is not visible. Also note that the default width of an input field is 20 characters.

The <label> Element

Notice the use of the <label> element in the example above.

The <label> tag defines a label for many form elements.

The <label> element is useful for screen-reader users, because the screen-reader will read out loud the label when the user focus on the input element.

The <label> element also help users who have difficulty clicking on very small regions (such as radio buttons or checkboxes) - because when the user clicks the text within the <label> element, it toggles the radio button/checkbox.

The for attribute of the <label> tag should be equal to the id attribute of the <input> element to bind them together.


Radio Buttons

The <input type="radio"> defines a radio button.

Radio buttons let a user select ONE of a limited number of choices.

示例

A form with radio buttons:

<form>
  <input type="radio" id="html" name="fav_language" value="HTML">
  <label for="html">HTML</label><br>
  <input type="radio" id="css" name="fav_language" value="CSS">
  <label for="css">CSS</label><br>
  <input type="radio" id="javascript" name="fav_language" value="JavaScript">
  <label for="javascript">JavaScript</label>
</form>

效果

This is how the HTML code above will be displayed in a browser:
Choose your favorite Web language:




Checkboxes

The <input type="checkbox"> defines a checkbox.

Checkboxes let a user select ZERO or MORE options of a limited number of choices.

示例

A form with checkboxes:

<form>
  <input type="checkbox" id="vehicle1" name="vehicle1" value="Bike">
  <label for="vehicle1"> I have a bike</label><br>
  <input type="checkbox" id="vehicle2" name="vehicle2" value="Car">
  <label for="vehicle2"> I have a car</label><br>
  <input type="checkbox" id="vehicle3" name="vehicle3" value="Boat">
  <label for="vehicle3"> I have a boat</label>
</form>

效果

This is how the HTML code above will be displayed in a browser:




The Submit Button

The <input type="submit"> defines a button for submitting the form data to a form-handler.
The form-handler is typically a file on the server with a script for processing input data.
The form-handler is specified in the form's action attribute.

示例

A form with a submit button:

<form action="/action_page.php">
  <label for="fname">First name:</label><br>
  <input type="text" id="fname" name="fname" value="John"><br>
  <label for="lname">Last name:</label><br>
  <input type="text" id="lname" name="lname" value="Doe"><br><br>
  <input type="submit" value="Submit">
</form>

效果

This is how the HTML code above will be displayed in a browser:







The Name Attribute for <input>

Notice that each input field must have a name attribute to be submitted.

If the name attribute is omitted, the value of the input field will not be sent at all.

示例

This example will not submit the value of the "First name" input field:

<form action="/action_page.php">
  <label for="fname">First name:</label><br>
  <input type="text" id="fname" value="John"><br><br>
  <input type="submit" value="Submit">
</form>

效果

This example will not submit the value of the "First name" input field: