android - 将原始文件复制到 SDCard 中？

Question

我的文件res/raw夹中有一些音频文件。由于某些原因，我想将此文件复制到我的 SDCard 时，我的应用程序启动。

我该怎么做？有人指导我吗？

Answer 1

从资源中读取，写入 SD 卡上的文件：

InputStream in = getResources().openRawResource(R.raw.myresource);
FileOutputStream out = new FileOutputStream(somePathOnSdCard);
byte[] buff = new byte[1024];
int read = 0;

try {
   while ((read = in.read(buff)) > 0) {
      out.write(buff, 0, read);
   }
} finally {
     in.close();
     out.close();
}

Answer 2

将文件从原始存储复制到外部存储：

这是我用来完成这项工作的一种方法，该方法接收资源 id 和存储所需的名称，例如：

copyFiletoExternalStorage(R.raw.mysound, "jorgesys_sound.mp3");

方法：

private void copyFiletoExternalStorage(int resourceId, String resourceName){
    String pathSDCard = Environment.getExternalStorageDirectory() + "/Android/data/" + resourceName;
    try{
        InputStream in = getResources().openRawResource(resourceId);
        FileOutputStream out = null;
        out = new FileOutputStream(pathSDCard);
        byte[] buff = new byte[1024];
        int read = 0;
        try {
            while ((read = in.read(buff)) > 0) {
                out.write(buff, 0, read);
            }
        } finally {
            in.close();
            out.close();
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

Answer 3

环境。getExternalStorageDirectory()此方法在 API 级别 29 中已弃用，并且不允许在给定路径上创建目录/文件。

下面的代码用于创建目录并从 /res/raw 目录下载文件。

如果您的设备具有Android 10（API 级别 29）或更高版本，它将在以下位置下载您的文件

文件管理器 --> 存储 --> Android --> 数据 --> com.yourapp.packagename --> 文件 --> FOLDER_NAME --> file_name.png

private void downloadFileFromRawFolder(){
try {
                InputStream in = getResources().openRawResource(
                        getResources().getIdentifier("file_name",
                                "raw", getPackageName())); // use only file name here, don't use extension
                File fileWithinMyDir = new File(checkFolder(), "file_name.png"); //Getting a file within the dir.
                Log.e("FILEPATH ", "fileWithinMyDir " + fileWithinMyDir);
                FileOutputStream out = new FileOutputStream(fileWithinMyDir);
                byte[] buff = new byte[1024 * 1024 * 2]; //2MB file
                int read = 0;

                try {
                    while ((read = in.read(buff)) > 0) {
                        out.write(buff, 0, read);
                    }
                } finally {
                    in.close();
                    out.close();
                }
                Log.d(TAG, "Download Done ");
            } catch (IOException e) {
                Log.e(TAG, "Download Failed " + e.getMessage());
                e.printStackTrace();
            }

}

---

/* 创建目录 */

    private File checkFolder() {
        String path;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            path = getExternalFilesDir(null).getAbsolutePath() + "FOLDER_NAME";
        } else {
            path = Environment.getExternalStorageDirectory() + "FOLDER_NAME";
        }
        File dir = new File(path);
        boolean isDirectoryCreated = dir.exists();
        if (!isDirectoryCreated) {
            isDirectoryCreated = dir.mkdir();
            Log.d("Folder", "Created = " + isDirectoryCreated);
        }

        Log.d("Folder", "Created ? " + isDirectoryCreated);
        return dir;
    }
}