Pycord中从列表调用bot.get_channel()返回None的问题

我通过斜杠命令让用户指定频道，把频道ID存入列表esendChannel。所有print语句（包括bot.get_channel()调用前的print(a_string)）都能输出正确的ID，但bot.get_channel()始终返回None。问题出在EmbedConfirmButton类的按钮回调逻辑里，esendChannel变量由底部的embedsend斜杠命令赋值。

完整代码如下：

eEdit = ["blank"]
esendChannel = ["blank"]
eTitle = ["blank"]
eDescription = ["blank"]
channel = []


class EmbedSend(discord.ui.Modal):
    def __init__(self, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)

        self.add_item(discord.ui.InputText(label="Title", value = eTitle[0]))
        self.add_item(discord.ui.InputText(label="Message Content", style=discord.InputTextStyle.long, value = eDescription[0])) 

    async def callback(self, interaction: discord.Interaction):
        eTitle[0] = self.children[0].value
        eDescription[0] = self.children[1].value

        esend = discord.Embed(title=''.join(eTitle), description=''.join(eDescription))
        eEdit[0] = [esend]

        print(eEdit)

        await interaction.response.send_message(embed = esend, view = EmbedConfirmButton(), ephemeral=True)
        



class EmbedConfirmButton(discord.ui.View):
    def __init__(self):
        super().__init__(timeout=None)

    @discord.ui.button(label="Send", custom_id="button-embededit", style=discord.ButtonStyle.blurple) 
    async def first_button_callback(self, button, interaction):
        finalembed = discord.Embed(title=eTitle, description=eDescription)
        finalembed.set_image(url="")
        s = [str(integer) for integer in esendChannel]
        a_string = "".join(s)
        print(a_string)
        await bot.get_channel(a_string).send(embed = finalembed)
        await interaction.response.send_message("test", ephemeral = True)
    
    @discord.ui.button(label="Edit", custom_id="button-embededit2", style=discord.ButtonStyle.blurple) 
    async def second_button_callback(self, button, interaction):
        modal = EmbedSend(title=eTitle[0])
        await interaction.response.send_modal(modal)
        await interaction.followup.send("test")

    @discord.ui.button(label="Cancel", custom_id="button-embedcancel", style=discord.ButtonStyle.blurple) 
    async def third_button_callback(self, button, interaction):
        await interaction.response.send_message("Canceled Interaction", ephemeral = True)
        return


@bot.slash_command()
@option("channel")
async def embedsend(ctx, channel:discord.TextChannel):
    modal = EmbedSend(title = "Embed Create")
    await ctx.send_modal(modal)
    await ctx.respond("Success", ephemeral = True)
    esendChannel[0] = str(channel.id)
    print(esendChannel)

问题原因 #

bot.get_channel()方法要求传入整数类型的频道ID，但你在代码里做了两个错误操作：

1. 在embedsend命令里把channel.id（原本是整数）转成字符串存入esendChannel
2. 在按钮回调里又把字符串拼接后传给get_channel()，而该方法不接受字符串参数，因此返回None

修复方案 #

方案1：修正类型问题（快速修复） #

1. 修改embedsend命令，直接存储整数ID：

   @bot.slash_command()
   @option("channel")
   async def embedsend(ctx, channel:discord.TextChannel):
       modal = EmbedSend(title = "Embed Create")
       await ctx.send_modal(modal)
       await ctx.respond("Success", ephemeral = True)
       esendChannel[0] = channel.id  # 去掉str()，存整数
       print(esendChannel)
   

2. 修改按钮回调，直接使用整数ID：

   @discord.ui.button(label="Send", custom_id="button-embededit", style=discord.ButtonStyle.blurple) 
   async def first_button_callback(self, button, interaction):
       finalembed = discord.Embed(title=''.join(eTitle), description=''.join(eDescription))
       finalembed.set_image(url="")
       target_channel = bot.get_channel(esendChannel[0])  # 直接用整数ID
       if target_channel:
           await target_channel.send(embed = finalembed)
           await interaction.response.send_message("消息已发送", ephemeral = True)
       else:
           await interaction.response.send_message("无法找到目标频道", ephemeral = True)
   

方案2：避免全局变量（更健壮的写法） #

全局列表存储状态容易引发并发冲突（比如多个用户同时使用命令时会覆盖数据），建议把频道ID通过参数传递给Modal和View：

1. 修改EmbedSend类，接收并存储目标频道ID：

   class EmbedSend(discord.ui.Modal):
       def __init__(self, *args, target_channel_id=None, **kwargs) -> None:
           super().__init__(*args, **kwargs)
           self.target_channel_id = target_channel_id
           self.add_item(discord.ui.InputText(label="Title", value = eTitle[0]))
           self.add_item(discord.ui.InputText(label="Message Content", style=discord.InputTextStyle.long, value = eDescription[0])) 
   
       async def callback(self, interaction: discord.Interaction):
           eTitle[0] = self.children[0].value
           eDescription[0] = self.children[1].value
   
           esend = discord.Embed(title=''.join(eTitle), description=''.join(eDescription))
           eEdit[0] = [esend]
   
           print(eEdit)
           # 把频道ID传递给View
           await interaction.response.send_message(embed = esend, view = EmbedConfirmButton(target_channel_id=self.target_channel_id), ephemeral=True)
   

2. 修改EmbedConfirmButton类，接收目标频道ID：

   class EmbedConfirmButton(discord.ui.View):
       def __init__(self, target_channel_id=None):
           super().__init__(timeout=None)
           self.target_channel_id = target_channel_id
   
       @discord.ui.button(label="Send", custom_id="button-embededit", style=discord.ButtonStyle.blurple) 
       async def first_button_callback(self, button, interaction):
           finalembed = discord.Embed(title=''.join(eTitle), description=''.join(eDescription))
           finalembed.set_image(url="")
           target_channel = bot.get_channel(self.target_channel_id)
           if target_channel:
               await target_channel.send(embed = finalembed)
               await interaction.response.send_message("消息已发送", ephemeral = True)
           else:
               await interaction.response.send_message("无法找到目标频道", ephemeral = True)
   

3. 修改embedsend命令，传递频道ID给Modal：

   @bot.slash_command()
   @option("channel")
   async def embedsend(ctx, channel:discord.TextChannel):
       modal = EmbedSend(title = "Embed Create", target_channel_id=channel.id)
       await ctx.send_modal(modal)
       await ctx.respond("Success", ephemeral = True)
   

内容的提问来源于stack exchange，提问作者Andrew Barnett