Android 11 kotlin jetpack compose如何将内容Uri转换为文件？

Question

这是我的密码

 val launcher1 = rememberLauncherForActivityResult(contract =
            ActivityResultContracts.GetContent()) { uri: Uri? ->
                imageUri1 = uri
            }

我必须像这样给视图模型

fun deviceComplete(deviceId: Int?, file:File?) = viewModelScope.launch{
}

如何将这个uri转换成文件..？？我真的不知道

Answer 1

你先请求许可了吗？

您可以通过以下方式实现这一目标

val state = rememberPermissionState(permission = Manifest.permission.READ_EXTERNAL_STORAGE

请参阅:https://medium . com/compose-in-the-room/requesting-permissions-with-easy-in-jetpack-compose-using-伴奏者-权限-API-76 D5 d9 ca 5 f 97

Answer 2

此示例用于图像Uri到文件

应用程序。实例-此实例来自Singleton应用程序类

@Suppress("DEPRECATION")
fun Uri.asFile(): File? {
    Application.instance.contentResolver
        .query(this, arrayOf(MediaStore.Images.Media.DATA), null, null, null)
        ?.use { cursor ->
            cursor.moveToFirst()
            val cursorData =
                cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA))

            return if (cursorData == null) {
                returnCursorData(this)?.let { File(it) }
            } else {
                File(cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA)))
            }
        }
    return null
}

@Suppress("DEPRECATION")
private fun returnCursorData(uri: Uri?): String? {
    val context = Application.instance

    if (DocumentsContract.isDocumentUri(context, uri)) {
        val wholeID = DocumentsContract.getDocumentId(uri)
        val splits = wholeID.split(":".toRegex()).toTypedArray()
        if (splits.size == 2) {
            val id = splits[1]
            val column = arrayOf(MediaStore.Images.Media.DATA)
            val sel = MediaStore.Images.Media._ID + "=?"

            val cursor: Cursor? = context.contentResolver.query(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                column, sel, arrayOf(id), null
            )

            val columnIndex: Int? = cursor?.getColumnIndex(column[0])
            if (cursor?.moveToFirst() == true) {
                return columnIndex?.let { cursor.getString(it) }
            }
            cursor?.close()
        }
    } else {
        return uri?.path
    }
    return null
}