注意：我使用 iced 作为 GUI TextInput 和 tokio 作为网络 TcpStream
我有以下几点：
#[derive(Debug, Clone)]
enum Message {
Session(Result<Connection, ConnectionError>), //Async Handler
SendMessage,
Send(Result<Connection, ConnectionError>), //Async Handler
InputChanged(String),
Button(usize, ButtonMessage),
None,
}
#[derive(Debug)]
enum ConnectionError {
ConnectError(usize),
SendError(usize),
}
#[derive(Debug)]
struct Connection {
stream: TcpStream,
loc: usize,
}
问题是我的 Connection 结构包含一个无法克隆的 TcpStream（无论如何克隆它在逻辑上没有意义）。
所以我得到了错误...
>the trait bound `Connection: Clone` is not satisfied
--> src\main.rs:27:10
|
27 | Session(Result<Connection, ConnectionError>), //Async Handler
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an implementor of trait `Clone`
|
= note: required because of the requirements on the impl of `Clone` for `std::result::Result<Connection, ConnectionError>`
= note: required by `clone`
= note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
>error[E0277]: the trait bound `ConnectionError: Clone` is not satisfied
--> src\main.rs:27:10
|
27 | Session(Result<Connection, ConnectionError>), //Async Handler
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an implementor of trait `Clone`
|
= note: required because of the requirements on the impl of `Clone` for `std::result::Result<Connection, ConnectionError>`
= note: required by `clone`
= note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
>error[E0277]: the trait bound `Connection: Clone` is not satisfied
--> src\main.rs:29:7
|
29 | Send(Result<Connection, ConnectionError>), //Async Handler
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an implementor of trait `Clone`
|
= note: required because of the requirements on the impl of `Clone` for `std::result::Result<Connection, ConnectionError>`
= note: required by `clone`
= note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
>error[E0277]: the trait bound `ConnectionError: Clone` is not satisfied
--> src\main.rs:29:7
|
29 | Send(Result<Connection, ConnectionError>), //Async Handler
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an implementor of trait `Clone`
|
= note: required because of the requirements on the impl of `Clone` for `std::result::Result<Connection, ConnectionError>`
= note: required by `clone`
= note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
所以我删除了克隆
#[derive(Debug)]
enum Message {
Session(Result<Connection, ConnectionError>), //Async Handler
SendMessage,
Send(Result<Connection, ConnectionError>), //Async Handler
InputChanged(String),
Button(usize, ButtonMessage),
None,
}
并得到以下错误：
>the trait bound `Message: Clone` is not satisfied
--> src\main.rs:516:15
|
516 | let input = TextInput::new(
| ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Message`
|
::: C:\Users\bratl\.cargo\registry\src\github.com-1ecc6299db9ec823\iced_native-0.3.0\src\widget\text_input.rs:84:22
|
84 | F: 'static + Fn(String) -> Message,
| --------------------- required by this bound in `iced_native::widget::text_input::TextInput::<'a, Message, Renderer>::new`
>error[E0599]: no method named `padding` found for struct `iced_native::widget::text_input::TextInput<'_, Message, iced_graphics::renderer::Renderer<iced_wgpu::backend::Backend>>` in the current scope
--> src\main.rs:522:4
|
26 | enum Message {
| ------------ doesn't satisfy `Message: Clone`
...
522 | .padding(15)
| ^^^^^^^ private field, not a method
|
= note: the method `padding` exists but the following trait bounds were not satisfied:
`Message: Clone`
所以我去了 TextInput 所在的位置并移除了 Clone。
#[derive(Debug)]
struct ClientAdminChatPaneContent {
scroll: scrollable::State,
input: text_input::State,
input_value: String,
}
#[derive(Debug)]
enum ChatPaneMessage {
InputChanged(String),
}
impl ClientAdminChatPaneContent {
fn new() -> Self {
ClientAdminChatPaneContent {
scroll: scrollable::State::new(),
input: text_input::State::new(),
input_value: String::from(""),
}
}
fn update(&mut self, message: ChatPaneMessage) {
match message {
ChatPaneMessage::InputChanged(value) => {
//println!("Input Changed: {}", value);
self.input_value = value;
}
}
}
fn view(&mut self) -> Element<Message> {
//Text Input
let input = TextInput::new(
&mut self.input,
"Message to Client",
&self.input_value,
Message::InputChanged,
)
.padding(15)
.size(30)
.on_submit(Message::SendMessage);
let text_input_container:Container<Message> = Container::new(input)
.width(Length::Fill)
.height(Length::Units(80))
.padding(10);
let scroll = Scrollable::new(&mut self.scroll)
.width(Length::Fill)
.spacing(10)
.align_items(Align::Start);
let scroll_container:Container<Message> = Container::new(scroll)
.width(Length::Fill)
.height(Length::Fill)
.padding(10);
let mut content = Column::new()
.spacing(5);
content = content.push(scroll_container);
content = content.push(text_input_container);
Container::new(content)
.width(Length::Fill)
.height(Length::Fill)
.padding(5)
.center_y()
.into()
}
fn clear_text(&mut self) {
self.input_value = String::from("");
}
}
然后我收到一个新错误：
>the trait bound `Message: Clone` is not satisfied
--> src\main.rs:516:15
|
516 | let input = TextInput::new(
| ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Message`
|
::: C:\Users\bratl\.cargo\registry\src\github.com-1ecc6299db9ec823\iced_native-0.3.0\src\widget\text_input.rs:84:22
|
84 | F: 'static + Fn(String) -> Message,
| --------------------- required by this bound in `iced_native::widget::text_input::TextInput::<'a, Message, Renderer>::new`
至于为什么，我不确定为什么 let input = TextInput::new( 需要实现 Clone。但是，假设我需要这个结构来实现克隆，没有 Message 由于 TCP 实现克隆......
如何获得特定项目的克隆，例如 TextInput 而不为每个项目派生它或者这是一个完全不同的问题？