android 拷贝assets目录文件到sdcard

在 Android 中，可以使用以下代码将 assets 目录中的文件拷贝到 SD 卡中：

private void copyAssetsToSDCard() {
    String[] files = null;
    try {
        files = getAssets().list("");
    } catch (IOException e) {
        e.printStackTrace();
    }

    for (String filename : files) {
        InputStream in = null;
        OutputStream out = null;
        try {
            in = getAssets().open(filename);
            String filePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + filename;
            out = new FileOutputStream(filePath);
            copyFile(in, out);
            in.close();
            in = null;
            out.flush();
            out.close();
            out = null;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

private void copyFile(InputStream in, OutputStream out) throws IOException {
    byte[] buffer = new byte[1024];
    int read;
    while ((read = in.read(buffer)) != -1) {
        out.write(buffer, 0, read);
    }
}

需要注意的是，同样需要在 AndroidManifest.xml 文件中添加以下权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />