dede channel typeid如何正确使用？

Of course! The typeid parameter in DedeCMS (织梦CMS) is one of the most fundamental and frequently used parameters, especially within its template engine ({dede:} tags). It's the key to organizing and displaying your website's content structure.

Here’s a complete breakdown of what typeid is, how it works, and how to use it effectively.

What is typeid?

In simple terms, typeid is the ID number of a specific channel (栏目) in your DedeCMS website.

• Channel (栏目): This is your website's content structure. Think of it as folders or categories on your computer. For example, you might have channels named "News," "Products," "Downloads," and "About Us."
• ID (标识符): Each channel is assigned a unique numeric ID automatically when you create it in the DedeCMS backend (后台).

The typeid parameter tells a DedeCMS tag which channel's content it should fetch or operate on.

Where is typeid Used?

You will primarily use typeid inside DedeCMS's built-in template tags ({dede:...}). Here are the most common use cases:

a) {dede:arclist} - Article List Tag

This is the most common use case. You use typeid to display a list of articles from a specific channel.

Purpose: To show a list of articles (文章) belonging to a certain channel and its sub-channels.

Syntax:

{dede:arclist typeid='1' titlelen='30' row='10'}
    <li>
        <a href="[field:arcurl/]">[field:title/]</a>
        <span>[field:pubdate function="MyDate('Y-m-d',@me)"/]</span>
    </li>
{/dede:arclist}

Parameters Explained:

• typeid='1': This is the key parameter. It tells the tag to get articles from the channel with ID 1. If you want articles from a channel and all its sub-channels, you just provide the top-level channel's ID.len='30'`: Limits the title length to 30 characters.
• row='10': Displays 10 articles.

Example: If you have a channel "News" with ID 3 and a sub-channel "Tech News" with ID 5, setting typeid='3' will display articles from both "News" and "Tech News".

b) {dede:channel} - Channel List Tag

This tag is used to display a list of channels (栏目导航).

Purpose: To create a navigation menu or a list of sub-channels.

Syntax:

{dede:channel typeid='2' type='son' currentstyle="<li class='thisclass'><a href='~typelink~'>~typename~</a></li>"}
    <li><a href="[field:typelink/]">[field:typename/]</a></li>
{/dede:channel}

Parameters Explained:

• typeid='2': Specifies the parent channel whose sub-channels you want to list. If typeid is not set, it lists all top-level channels.
• type='son': Tells the tag to list only the direct sub-channels of the channel specified in typeid. Other values include self (only the channel itself) and top (all top-level channels).
• currentstyle: Allows you to apply special CSS styling to the channel that is currently being viewed.

c) {dede:field} - Field Tag

This tag is used to display a specific field of the current channel.

Purpose: To get information about the channel you are currently on, such as its name, description, or SEO title.

Syntax:

<h1>{dede:field name='typename'/}</h1>
<p>{dede:field name='description'/}</p>
<meta name="keywords" content="{dede:field name='keywords'/}" />

How typeid is involved: This tag is "context-aware." When you are on a channel page (e.g., yourdomain.com/plus/list.php?tid=3), DedeCMS automatically knows you are on channel ID 3. The {dede:field} tag then fetches the fields for that specific channel. You don't need to manually add typeid here, but it's being used "behind the scenes."

How to Find a Channel's typeid?

You need to know the ID number to use it. Here’s how to find it:

1. Log in to your DedeCMS Backend.
2. Go to the "Content Management" (内容管理) section in the left menu.
3. Click on "Channel Management" (栏目管理).
4. You will see a list of all your channels. The first column is "ID". This is the number you need for the typeid parameter.

From the table above:

• The typeid for "News" is 2.
• The typeid for "Tech News" is 5.

Advanced Usage

a) Displaying Articles from Multiple Channels

You can specify multiple channel IDs by separating them with commas ().

Example: To display articles from both the "News" (ID 2) and "Products" (ID 8) channels:

{dede:arclist typeid='2,8' row='15'}
    <!-- ... -->
{/dede:arclist}

b) Excluding a Channel

You can exclude a specific channel by prefixing its ID with a minus sign ().

Example: To display articles from all sub-channels of "News" (ID 2) except for "Tech News" (ID 5):

{dede:arclist typeid='2,-5' row='15'}
    <!-- ... -->
{/dede:arclist}

Summary

In short, typeid is your bridge between your website's channel structure and the content you display on the front end. Mastering its use is essential for building dynamic and well-organized websites with DedeCMS.