Question

除了引用TAG之外，我的活动中的几乎所有内容都运行正常。 TAG得到一条红线并说：'TAG' has private access in 'android.support.v4.app.FragmentActivity'。

MainActivity（不含导入） -

public class MainActivity extends AppCompatActivity {
    public static final String DATA_PATH = Environment
            .getExternalStorageDirectory().toString() + "/MainActivity";
    public static final String lang = "eng";

    protected Button _button;
    protected ImageView _image;
    protected TextView _field;
    protected String _path;
    protected boolean _taken;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String[] paths = new String[] { DATA_PATH, DATA_PATH + "tessdata/" };

        for (String path : paths) {
            File dir = new File(path);
            if (!dir.exists()) {
                if (!dir.mkdirs()) {
                    Log.v(TAG, "ERROR: Creation of directory " + path + " on sdcard failed");
                    return;
                } else {
                    Log.v(TAG, "Created directory " + path + " on sdcard");
                }
            }

        }

        if (!(new File(DATA_PATH + "tessdata/" + lang + ".traineddata")).exists()) {
            try {

                AssetManager assetManager = getAssets();
                InputStream in = assetManager.open("tessdata/" + lang + ".traineddata");
                //GZIPInputStream gin = new GZIPInputStream(in);
                OutputStream out = new FileOutputStream(DATA_PATH
                        + "tessdata/" + lang + ".traineddata");

                // Transfer bytes from in to out
                byte[] buf = new byte[1024];
                int len;
                //while ((lenf = gin.read(buff)) > 0) {
                while ((len = in.read(buf)) > 0) {
                    out.write(buf, 0, len);
                }
                in.close();
                //gin.close();
                out.close();

                Log.v(TAG, "Copied " + lang + " traineddata");
            } catch (IOException e) {
                Log.e(TAG, "Was unable to copy " + lang + " traineddata " + e.toString());
            }
        }

        _image = ( ImageView ) findViewById( R.id.image );
        _field = ( TextView ) findViewById( R.id.field );
        _button = ( Button ) findViewById( R.id.button );
        _button.setOnClickListener( new ButtonClickHandler() );

        _path = Environment.getExternalStorageDirectory() + "/Login Data.jpg";
    }

    public class ButtonClickHandler implements View.OnClickListener
    {
        public void onClick( View view ){
            startCameraActivity();
        }
    }

    protected void startCameraActivity()
    {
        File file = new File( _path );
        Uri outputFileUri = Uri.fromFile( file );

        Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE );
        intent.putExtra( MediaStore.EXTRA_OUTPUT, outputFileUri );

        startActivityForResult( intent, 0 );
    }

    protected void onPhotoTaken()
    {
        _taken = true;

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = 4;

        Bitmap bitmap = BitmapFactory.decodeFile( _path, options );
        _image.setImageBitmap(bitmap);

        _field.setVisibility( View.GONE );

        ExifInterface exif = new ExifInterface(_path);

        int exifOrientation = exif.getAttributeInt(
                ExifInterface.TAG_ORIENTATION,
                ExifInterface.ORIENTATION_NORMAL);

        int rotate = 0;

        switch (exifOrientation) {
            case ExifInterface.ORIENTATION_ROTATE_90:
                rotate = 90;
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                rotate = 180;
                break;
            case ExifInterface.ORIENTATION_ROTATE_270:
                rotate = 270;
                break;
        }

        if (rotate != 0) {
            int w = bitmap.getWidth();
            int h = bitmap.getHeight();

            // Setting pre rotate
            Matrix mtx = new Matrix();
            mtx.preRotate(rotate);

            // Rotating Bitmap & convert to ARGB_8888, required by tess
            bitmap = Bitmap.createBitmap(bitmap, 0, 0, w, h, mtx, false);
        }
        bitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);

        TessBaseAPI baseApi = new TessBaseAPI();
        baseApi.init(DATA_PATH, lang);
        baseApi.setImage(bitmap);
        String recognizedText = baseApi.getUTF8Text();
        baseApi.end();
    }

    @Override
    protected void onSaveInstanceState( Bundle outState ) {
        outState.putBoolean( MainActivity.PHOTO_TAKEN, _taken );
    }

    @Override
    protected void onRestoreInstanceState( Bundle savedInstanceState)
    {
        Log.i( "MakeMachine", "onRestoreInstanceState()");
        if( savedInstanceState.getBoolean( MainActivity.PHOTO_TAKEN ) ) {
            onPhotoTaken();
        }
    }

Answer 1

您应该在MainActivity中为您的代码定义一个常量：

private static final String TAG = "MainActivity"

Answer 2

尝试以下

private static final String TAG = MainActivity.class.getSimpleName();

您可以在任何活动或片段中使用此字段。

Answer 3

这只是Android告诉我们尚未定义TAG的一种方式。要在当前文件中定义TAG，我们可以转到MainActivity Class并键入“ logt”，您将从Android Studio获得一些自动代码建议，然后在其中按Enter，然后将得到以下代码

private static final String TAG = "MainActivity";

将其添加到代码中后，错误将消失

Answer 4

实用说明：以下是更好的方法

private static final String TAG = MainActivity.class.getSimpleName();

相比：

private static final String TAG = "MainActivity";

＆＃39; TAG＆＃39;在＆＃39; android.support.v4.app.FragmentActivity＆＃39;中拥有私人访问权限。

4 个答案: