基于Kotlin Compose Multiplatform Desktop调用摄像头并拍照

针对仅需基础拍照的需求，无需复杂的OpenCV，直接借助Compose Desktop底层依赖的JavaFX API即可实现，步骤如下：

核心实现思路 #

利用JavaFX的MediaDevices获取系统摄像头，通过MediaCapture实现画面预览与拍照，再通过Compose的JavaFxComponent将预览画面嵌入Compose界面。

完整代码示例 #

import androidx.compose.foundation.layout.*
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.*
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import androidx.compose.ui.window.Window
import androidx.compose.ui.window.application
import javafx.scene.image.ImageView
import javafx.scene.media.MediaCapture
import javafx.scene.media.MediaDevices
import java.io.File

fun main() = application {
    Window(title = "摄像头拍照工具", onCloseRequest = ::exitApplication) {
        var imageView by remember { mutableStateOf<ImageView?>(null) }
        var capture: MediaCapture? by remember { mutableStateOf(null) }

        LaunchedEffect(Unit) {
            // 获取默认摄像头
            val camera = MediaDevices.getDefaultVideoDevice()
            camera?.let {
                val mediaCapture = MediaCapture(it)
                val preview = ImageView().apply {
                    fitWidth = 640.0
                    fitHeight = 480.0
                    isPreserveRatio = true
                }
                mediaCapture.start()
                preview.image = mediaCapture.view
                imageView = preview
                capture = mediaCapture
            }
        }

        Column(
            modifier = Modifier.fillMaxSize().padding(16.dp),
            horizontalAlignment = Alignment.CenterHorizontally,
            verticalArrangement = Arrangement.Center
        ) {
            imageView?.let { view ->
                JavaFxComponent(
                    modifier = Modifier.size(640.dp, 480.dp),
                    factory = { view }
                )
                Spacer(modifier = Modifier.height(16.dp))
                Button(onClick = {
                    capture?.let { cap ->
                        // 拍照并保存到指定路径
                        val photoFile = File(System.getProperty("user.home"), "camera_photo.jpg")
                        cap.takePhoto(photoFile)
                    }
                }) {
                    Text("拍照")
                }
            } ?: Text("未检测到可用摄像头")
        }
    }
}

注意事项 #

• 权限配置：Windows/macOS/Linux需要开启应用的摄像头访问权限，首次运行系统会弹出权限请求，允许即可。
• 路径调整：代码中默认将照片保存到用户目录下的camera_photo.jpg，可根据需求修改photoFile的路径。
• 依赖说明：Compose Desktop项目默认已包含JavaFX相关依赖，无需额外添加。

内容的提问来源于stack exchange，提问作者codaman