Basic Operations Questions
In the following section, you will find commonly asked questions and
answers regarding basic usage of the library, as well as
language-specific tips when using this library.
How should I safely check a type?
[!WARNING]
Direct casting (e.g., (Type)type) is the least recommended
way of casting, as it can throw an InvalidCastException
when the object isn't the desired type.
Please refer to this post for more details.
In Discord.Net, the idea of polymorphism is used throughout. You may
need to cast the object as a certain type before you can perform any
action.
A good and safe casting example:
[!code-csharpCasting]
How do I send a message?
[!TIP]
The GetChannel method by default returns an IChannel, allowing
channel types such as IVoiceChannel, ICategoryChannel
to be returned; consequently, you cannot send a message
to channels like those.
Any implementation of IMessageChannel has a SendMessageAsync
method. You can get the channel via GetChannel under the client.
Remember, when using Discord.Net, polymorphism is a common recurring
theme. This means an object may take in many shapes or form, which
means casting is your friend. You should attempt to cast the channel
as an IMessageChannel or any other entity that implements it to be
able to message.
How can I tell if a message is from X, Y, Z channel?
You may check the message channel type. Visit Glossary to see the
various types of channels.
How can I get the guild from a message?
There are 2 ways to do this. You can do either of the following,
- Cast the user as an IGuildUser and use its IGuild property.
- Cast the channel as an IGuildChannel and use its IGuild property.
How do I add hyperlink text to an embed?
Embeds can use standard markdown in the description field as well
as in field values. With that in mind, links can be added with
[text](link).
How do I add reactions to a message?
Any entity that implements IUserMessage has an AddReactionAsync
method. This method expects an IEmote as a parameter.
In Discord.Net, an Emote represents a custom-image emote, while an
Emoji is a Unicode emoji (standard emoji). Both Emoji and Emote
implement IEmote and are valid options.
[!code-csharpEmoji]
[!code-csharpEmoji]
What is a "preemptive rate limit?"
A preemptive rate limit is Discord.Net's way of telling you to slow
down before you get hit by the real rate limit. Hitting a real rate
limit might prevent your entire client from sending any requests for
a period of time. This is calculated based on the HTTP header
returned by a Discord response.
Why am I getting so many preemptive rate limits when I try to add more than one reactions?
This is due to how HTML header works, mistreating
0.25sec/action to 1sec. This causes the lib to throw preemptive rate
limit more frequently than it should for methods such as adding
reactions.
Can I opt-out of preemptive rate limits?
Unfortunately, not at the moment. See #401.
