如何使用新的 Activity Contracts API 将图像从相机上传到服务器？

Question

我正在尝试使用相机图像和新的 Activity 合同方法将图像上传到服务器，但出现异常，例如：我选择的路径没有这样的文件或目录。

这是我到目前为止所做的：

private fun takeImage() {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
        lifecycleScope.launchWhenStarted {
            getTmpFileUri().let { uri ->
                latestTmpUri = uri
                getImageResult.launch(uri)
            }
        }
    } else {
        requestCameraPermission.launch(Manifest.permission.CAMERA)
    }
}

private fun getTmpFileUri(): Uri {
    val timeStamp: String = SimpleDateFormat("ddMMyyyy", Locale.getDefault()).format(Date())
    val tmpFile = File.createTempFile(timeStamp, ".png", cacheDir).apply {
        createNewFile()
        deleteOnExit()
    }

    return FileProvider.getUriForFile(applicationContext, "${BuildConfig.APPLICATION_ID}.provider", tmpFile)
}

private val getImageResult = registerForActivityResult(ActivityResultContracts.TakePicture()) { isSuccess ->
    if (isSuccess) {
        latestTmpUri?.let {
            //loadImage(it, binding.imgProfile)
            image = File(it.path.toString())
            uploadImage()
        }
    }
}

 if (image != null) {
        profileImage = image.toMultipartBody("profile_image")
    } // and than code for api calls which use profileImage to upload

fun File?.toMultipartBody(name: String): MultipartBody.Part? {
    this ?: return null
    return MultipartBody.Part.createFormData(
        name,
        this.name,
        RequestBody.create(getMimeType().toMediaTypeOrNull(), this)
    )
}

private fun File.getMimeType(): String {
    var type: String? = null
    val url = this.toURI().toURL().toString()
    val extension = url.substringAfterLast(".")
    return when (extension.lowercase(Locale.getDefault())) {
        "jpg", "jpeg", "png" -> "image/$extension"
        "mp4" -> "video/$extension"
        "pdf" -> "application/$extension"
        else -> "image/*"
    }
}

感谢任何帮助！！

Answer 1

我是这样解决这个问题的：

首先在使用 private fun getTmpFileUri() 创建 tempFile 时：Uri 检索 tempFile 的绝对路径并将其存储在全局变量中，如下所示：

private fun getTmpFileUri(): Uri {
    val timeStamp: String = SimpleDateFormat("ddMMyyyy", Locale.getDefault()).format(Date())
    val tmpFile = File.createTempFile(timeStamp, ".png", cacheDir).apply {
        createNewFile()
        deleteOnExit()
    }
    imagePath = tmpFile.absolutePath // store file path in variable

    return FileProvider.getUriForFile(applicationContext, "${BuildConfig.APPLICATION_ID}.provider", tmpFile)
}

现在使用该路径创建图像文件如下：

 private val getImageResult = registerForActivityResult(ActivityResultContracts.TakePicture()) { isSuccess ->
    if (isSuccess) {
        latestTmpUri?.let {
            image = File(imagePath)
            uploadImage()
        }
    }
}

现在您可以使用可变图像在 uploadImage() 方法中上传您的图像文件。

如何使用新的 Activity Contracts API 将图像从相机上传到服务器？

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