在 onActivityResult 中收到“content://”Uri 后从 MediaStore 获取 PDF？

Question

我开始一个ACTION_GET_CONTENT意图来选择 PDF：

override fun routeToFilePicker() {
    val intent = Intent()
    intent.type = MediaType.PDF.toString()
    intent.action = Intent.ACTION_GET_CONTENT
    activity.startActivityForResult(
        Intent.createChooser(intent, "Select PDF"),
        REQUEST_CODE_PDF_PICKER
    )
}

然后onActivityResult我尝试从 Uri ( ) 创建 PDF content//:path：

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (resultCode == Activity.RESULT_OK && requestCode == REQUEST_CODE_PDF_PICKER ) {
        data?.data?.let { pdfUri: Uri ->
            val pdfFile: File = pdfUri.toFile() <-- chrash
            ...
        }
    }
}

pdfUri.toFile()导致致命异常：

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1003, result=-1, data=Intent { dat=content://com.android.providers.downloads.documents/document/3569 flg=0x1 }} to activity {my.package.name.activity}: java.lang.IllegalArgumentException: Uri lacks 'file' scheme: content://com.android.providers.downloads.documents/document/3569

Caused by: java.lang.IllegalArgumentException: Uri lacks 'file' scheme: content://com.android.providers.downloads.documents/document/3569

我需要一个文件才能将页面转换为图像。
如何从 MediaStore 返回的 Uri 中获取 PDF 文件？

Answer 1

这就是我获取 pdf 文件的方式：

val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
                            type = "application/pdf"
                            addCategory(Intent.CATEGORY_OPENABLE)
                            flags = flags or Intent.FLAG_GRANT_READ_URI_PERMISSION
                        }
                        startActivityForResult(intent, 111)

在你的里面OnActivityResult(requestCode:Int,resultCode:Int,data:Intent?)

if (resultCode == Activity.RESULT_OK) {
            when (requestCode) {
//                101 -> {
//                    data?.data?.also { uri ->
//                        Log.i(TAG, "Uri: $uri")
//                        baseAdapter?.add(ImageArray(null, null, uri.toString()))
//                    }
//                }
                111 -> {
                    data?.data?.also { documentUri ->
                        baseActivity.contentResolver?.takePersistableUriPermission(
                                documentUri,
                                Intent.FLAG_GRANT_READ_URI_PERMISSION
                        )
                        val file = DocumentUtils.getFile(baseActivity,documentUri)//use pdf as file 
                    }
                }
            }

        }

将 Uri 隐藏到文件的 Singleton 类：

object DocumentUtils {
    fun getFile(mContext: BaseActivity?, documentUri: Uri): File {
        val inputStream = mContext?.contentResolver?.openInputStream(documentUri)
        var file =  File("")
        inputStream.use { input ->
            file =
                File(mContext?.cacheDir, System.currentTimeMillis().toString()+".pdf")
            FileOutputStream(file).use { output ->
                val buffer =
                    ByteArray(4 * 1024) // or other buffer size
                var read: Int = -1
                while (input?.read(buffer).also {
                        if (it != null) {
                            read = it
                        }
                    } != -1) {
                    output.write(buffer, 0, read)
                }
                output.flush()
            }
        }
        return file
    }
} 

PS：不要忘记在运行时请求许可

Manifest.permission.WRITE_EXTERNAL_STORAGE
Manifest.permission.READ_EXTERNAL_STORAGE