android - 检查权限并重新加载 Activity

Question

大家好我在检查运行时权限后遇到加载 Activity 元素的问题我为 Lollipop 制作了一个应用程序但现在我需要更新到 Marshmallow 所以我遇到了这个问题

我有一个 MainActivity

        public static final int REQUEST_ID_MULTIPLE_PERMISSIONS = 1;

        @Override
            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);

                setContentView(R.layout.activity_main);

                if(checkAndRequestPermissions(this)) {
                    //Var created
                    Internetstatus = (TextView) findViewById(R.id.statusInternet);

                    if (!verificaConexion(this)) {
                        Internetstatus.setText("NOT CONNECTED");
                    } else {
                        Internetstatus.setText("CONNECTED");
                    }
                }
            }


            public static boolean verificaConexion(Context ctx) {

                boolean bConectado = false;
                ConnectivityManager cm = (ConnectivityManager) ctx.getSystemService(Context.CONNECTIVITY_SERVICE);
                NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
                if (activeNetwork != null) {
                        bConectado = true;
                }
                return bConectado;
            }




        private  boolean checkAndRequestPermissions(Context ctx) {
            if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                Toast.makeText(this, "Checking permission…", Toast.LENGTH_SHORT).show ();
                //List of permissions
                int permissionInternet = ContextCompat.checkSelfPermission(this,
                        Manifest.permission.INTERNET);

                int permissionAccessNetwork = ContextCompat.checkSelfPermission(this,
                        Manifest.permission.ACCESS_NETWORK_STATE);

                int permissionReadExternal = ContextCompat.checkSelfPermission(this,
                        Manifest.permission.READ_EXTERNAL_STORAGE);
                int permissionWriteExternal = ContextCompat.checkSelfPermission(this,
                        Manifest.permission.WRITE_EXTERNAL_STORAGE);


                List<String> listPermissionsNeeded = new ArrayList<>();

                //Verify status of permissions
                if (permissionInternet != PackageManager.PERMISSION_GRANTED) {
                    listPermissionsNeeded.add(Manifest.permission.INTERNET);
                }
                if (permissionAccessNetwork != PackageManager.PERMISSION_GRANTED) {
                    listPermissionsNeeded.add(Manifest.permission.ACCESS_NETWORK_STATE);
                }
                if (permissionReadExternal != PackageManager.PERMISSION_GRANTED) {
                    listPermissionsNeeded.add(Manifest.permission.READ_EXTERNAL_STORAGE);
                }
                if (permissionWriteExternal != PackageManager.PERMISSION_GRANTED) {
                    listPermissionsNeeded.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
                }


                if (!listPermissionsNeeded.isEmpty()) {
                    ActivityCompat.requestPermissions(this, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]), REQUEST_ID_MULTIPLE_PERMISSIONS);
                    return false;
                }


                return true;

            }
            return true;
        }


    }

是的，我在 Activity 中有更多元素，但对于示例来说，只有单个文本很好 :)，检查权限很好，但是当我按下允许权限时， Activity 文本状态是默认文本 xD! “小文本”，所以 setText 不起作用，但如果我关闭应用程序并再次打开，一切都可以正常工作，因为我已经允许了许可。嘿，我是第一次为棉花糖制作应用程序，所以可能问题很愚蠢哈哈哈。

好吧，在那之后不起作用，我想也许如果我创建一个新 Activity LoadActivity，我可以在那里检查权限(将功能检查和所有关于检查权限从 MainActivity 移到 LoadActivity)，如果条件很好，我初始化 MainActivity，这个很好的启动新 Activity (LoadActivity)，我检查权限但在我允许权限后启动 MainActivity 不工作

新的 LoadActivity 是

public class LoadActivity extends AppCompatActivity {

    public static final int REQUEST_ID_MULTIPLE_PERMISSIONS = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_load);

        if(checkAndRequestPermissions(this)) {
            Intent intent = new Intent(this, MainActivity.class);
            startActivityForResult(intent, 0);
        }


    }

    private  boolean checkAndRequestPermissions(Context ctx) {
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            Toast.makeText(this, "Checking permission…", Toast.LENGTH_SHORT).show ();
            //List of permissions
            int permissionInternet = ContextCompat.checkSelfPermission(this,
                    Manifest.permission.INTERNET);

            int permissionAccessNetwork = ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_NETWORK_STATE);

            int permissionReadExternal = ContextCompat.checkSelfPermission(this,
                    Manifest.permission.READ_EXTERNAL_STORAGE);
            int permissionWriteExternal = ContextCompat.checkSelfPermission(this,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE);


            List<String> listPermissionsNeeded = new ArrayList<>();

            //Verify status of permissions
            if (permissionInternet != PackageManager.PERMISSION_GRANTED) {
                listPermissionsNeeded.add(Manifest.permission.INTERNET);
            }
            if (permissionAccessNetwork != PackageManager.PERMISSION_GRANTED) {
                listPermissionsNeeded.add(Manifest.permission.ACCESS_NETWORK_STATE);
            }
            if (permissionReadExternal != PackageManager.PERMISSION_GRANTED) {
                listPermissionsNeeded.add(Manifest.permission.READ_EXTERNAL_STORAGE);
            }
            if (permissionWriteExternal != PackageManager.PERMISSION_GRANTED) {
                listPermissionsNeeded.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
            }


            if (!listPermissionsNeeded.isEmpty()) {
                ActivityCompat.requestPermissions(this, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]), REQUEST_ID_MULTIPLE_PERMISSIONS);
                return false;
            }


            return true;

        }
        return true;
    }
}

我希望有人能帮助我:D问候

Answer 1

你检查权限是否被授予，然后调用 setText 否则什么都不做。

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if(checkAndRequestPermissions(this)) { //Var created
        Internetstatus = (TextView) findViewById(R.id.statusInternet);
        if (!verificaConexion(this)) {
            Internetstatus.setText("NOT CONNECTED");
        } else {
            Internetstatus.setText("CONNECTED"); 
        } 
    } 
}

如果您想在授予权限后设置文本，那么您应该覆盖方法 onRequestPermissionResult 并从中再次调用 setText。 Activity的onCreate方法在获得权限后不会再被调用。

这就是为什么它在您关闭并重新打开应用程序时起作用的原因，因为您的应用程序的新打开会再次调用 onCreate Activity ，现在您的方法 checkAndRequestPermissions 返回 true => setText 将被调用