检查特定消息是否仍在频道中？ - 不和谐.py答案

【问题标题】：check if a specific message is still in the channel? - Discord.py检查特定消息是否仍在频道中？ - 不和谐.py
【发布时间】：2021-11-28 01:03:11
【问题描述】：

我一直在为我的 discord 机器人创建一个 connect 4 游戏，游戏本身运行良好，但是如果有人删除了包含棋盘和用户玩游戏的反应的消息，游戏将开始中断并且无法正常运行，直到有人重新启动机器人：

turn = 0 #switches between 0 and 1 during the game

game_over = False
while not game_over:
    try:

        reaction, user = await client.wait_for("reaction_add", check = check)
        if turn == 0:
            #do stuff depending on what the emoji reaction is
            if winning move():
                game_over = True
        else:
            #do stuff depending on what the emoji reaction is
            if winning_move():
                game_over = True
        #more things that aren't necessary to show

在有人删除消息和/或检查消息是否已被删除并通过它将变量更改为 True 后，我有没有办法将 game_over 更改为 True？例如：

#If the board's not in the channel:
  await message.channel.send("Board was not found")
  game_over = True

任何帮助将不胜感激！

【问题讨论】：

标签： python discord discord.py

【解决方案1】：

您可以使用asyncio.wait() 函数。请参阅下面的示例，其中我实现了简单的小游戏逻辑。

@client.command()
async def mini_game(ctx):
    message = await ctx.send("test message")  # send first message
    done, pending = await asyncio.wait(
        [
            asyncio.create_task(client.wait_for("reaction_add", check=your_check)),  # specify `your_check` function
            asyncio.create_task(client.wait_for("message_delete", check=lambda m: m == message))
        ],
        return_when=asyncio.FIRST_COMPLETED,
        timeout=30  # you can specify timeout here
    )
    if done == set():
        pass  # if time limit exceeded
    else:
        coro = done.pop().result()
        try:
            reaction, member = coro  # if user `member` has added `reaction`
        except TypeError:
            pass  # if message has been deleted

您可以调整此代码以满足您的需要。

【讨论】：

【解决方案2】：

您可以通过简单地尝试获取带有删除前 id 的消息来检查消息是否已被删除。如果这返回 NotFound 错误，则该消息已被删除：

def is_message_deleted(ctx, message_id):
    try:
        await ctx.fetch_message(message_id) #try to fetch the message
        return False
    except discord.error.NotFound: #if a NotFound error appears, the message is either not in this channel or deleted
        return True

然后你可以在你的代码中包含这个函数：

if is_message_deleted(ctx, board_message.id):
    await message.channel.send("Board was not found")
    game_over = True

参考资料：

context.fetch_message()

【讨论】：