Question

我在网上搜索了很多解决方案。但是，似乎到处使用的代码在这里仍然无法正确执行。这可能是一个愚蠢的错误，但它使我在数小时内处于优势。

public class FileActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_file);

        Intent intent = getIntent();
        String filepath = intent.getStringExtra("KEY");

        TextView pane = findViewById(R.id.TextPanel);
        StringBuilder text = new StringBuilder();
        try {
           BufferedReader br = new BufferedReader(new FileReader(filepath));
            String line;
            while ((line = br.readLine()) != null) {
                text.append(line);
                text.append('\n');
            }
            br.close();

        }
        catch (IOException e) {
            Toast.makeText(getApplicationContext(),filepath,Toast.LENGTH_LONG).show();
            e.printStackTrace();
        }

        pane.setText(text);

    }
}

问题：我收到IOException。虽然文件路径是绝对的。

编辑： Works。它需要在代码中指定权限。

使用以下代码来自：Exception 'open failed: EACCES (Permission denied)' on Android

    // Storage Permissions
private static final int REQUEST_EXTERNAL_STORAGE = 1;
private static String[] PERMISSIONS_STORAGE = {
        Manifest.permission.READ_EXTERNAL_STORAGE,
        Manifest.permission.WRITE_EXTERNAL_STORAGE
};

/**
 * Checks if the app has permission to write to device storage
 *
 * If the app does not has permission then the user will be prompted to grant permissions
 *
 * @param activity
 */
public static void verifyStoragePermissions(Activity activity) {
    // Check if we have write permission
    int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);

    if (permission != PackageManager.PERMISSION_GRANTED) {
        // We don't have permission so prompt the user
        ActivityCompat.requestPermissions(
                activity,
                PERMISSIONS_STORAGE,
                REQUEST_EXTERNAL_STORAGE
        );
    }
}

Answer 1

如果确定文件路径正确，则需要验证是否具有文件读写权限。请在AndroidManifest.xml上将其写入。

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

如果Android设备的版本号大于或等于6，则需要获取运行时权限。

如何在textview中显示文本文件？

1 个答案: