讀取設定值

驅動程式可以使用元件架構的結構化設定，讀取產品組裝時提供的值 (請參閱提供設定)。請參閱 C++ 和 Rust 驅動程式範例。

在 CML 中加入設定用途

在驅動程式庫 CML 中，use以設定名稱 config 能力：

use: [
    {
        config: "fuchsia.power.SuspendEnabled",
        key: "suspend_enabled",
        type: "bool",
    },
],

設定版本

您需要在建構檔案中手動宣告資訊清單目標，才能使用建構目標產生可存取設定的程式庫：

C++

fuchsia_component_manifest("component-manifest") {
  component_name = "example_config_driver"
  manifest = "meta/config_driver.cml"
}

fuchsia_structured_config_cpp_elf_lib("example-config-driver-config") {
  cm_label = ":component-manifest"
}

fuchsia_driver_component("component") {
  cm_label = ":component-manifest"
  deps = [
    ":bind",
    ":driver",
  ]
  info = "meta/component-info.json"
}

fuchsia_cc_driver("driver") {
  output_name = "example_config_driver"
  sources = [ "config_driver.cc" ]
  deps = [
    ":example-config-driver-config",
    "//sdk/lib/driver/component/cpp",
    "//src/devices/lib/driver:driver_runtime",
  ]
}

荒漠油廠

fuchsia_component_manifest("manifest") {
  component_name = "example_config_driver_rust"
  manifest = "meta/config_driver.cml"
}

fuchsia_structured_config_rust_lib("example-config-driver-config") {
  cm_label = ":manifest"
}

fuchsia_driver_component("component") {
  cm_label = ":manifest"
  deps = [
    ":bind",
    ":driver",
  ]
  info = "meta/component-info.json"
}

fuchsia_rust_driver("driver") {
  edition = "2024"

  output_name = "example_config_driver_rust"
  sources = [ "src/lib.rs" ]
  deps = [
    ":example-config-driver-config",
    "//sdk/fidl/fuchsia.driver.framework:fuchsia.driver.framework_rust",
    "//sdk/lib/driver/component/rust",
    "//sdk/lib/driver/runtime/rust",
    "//sdk/rust/zx",
    "//third_party/rust_crates:log",
  ]
}

在程式碼中存取設定

現在您可以使用產生的程式庫，在程式碼中存取設定值。

  1. 加入程式庫依附元件：

    C++

    #include "examples/drivers/config/cpp/example_config_driver_config.h"

    荒漠油廠

    use example_config_driver_config::Config;

  2. 使用程式庫從驅動程式庫的啟動引數存取設定：

    C++

    auto config = take_config<example_config_driver_config::Config>();
fdf::info("My config value is: {}", config.suspend_enabled());

    荒漠油廠

    let config = context.take_config::<Config>()?;
info!("My config value is: {}", config.suspend_enabled);