android - 如果应用程序在离线模式下启动，进度对话框应在连接到互联网后隐藏

Question

如果我的应用程序在离线模式下启动，并且在我打开 wifi/移动数据后，我的进度对话框应该隐藏和显示 snackbar，而无需重新启动应用程序。

我按照这个例子:https://www.androidhive.info/2012/07/android-detect-internet-connection-status/

但是当我打开或关闭互联网时，如果不重新启动应用程序，它不会立即显示效果。

代码:

package com.jimmytrivedi.lapitchat.Activity;

import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FacebookAuthProvider;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.jimmytrivedi.lapitchat.Application.LapitChat;
import com.jimmytrivedi.lapitchat.Interface.ConnectivityReceiverListener;
import com.jimmytrivedi.lapitchat.R;
import com.jimmytrivedi.lapitchat.Receiver.ConnectivityReceiver;

import butterknife.BindView;
import butterknife.ButterKnife;

public class StartActivity extends AppCompatActivity implements View.OnClickListener, ConnectivityReceiverListener {

    private static final String TAG = StartActivity.class.getName();

    @BindView(R.id.signup)
    Button signup;
    @BindView(R.id.login)
    Button login;
    @BindView(R.id.phoneAuth)
    Button phoneAuth;
    @BindView(R.id.facebook_button)
    LoginButton facebookButton;
    @BindView(R.id.relative_layout)
    RelativeLayout relativeLayout;

    private CallbackManager mCallbackManager;
    private FirebaseAuth mAuth;
    private ProgressDialog progressDialog;
    private FirebaseUser currentUser;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start);
        ButterKnife.bind(this);

        init();
        checkConnection();
        setClickListener();
        clickOnFacebook();

    }

    private void clickOnFacebook() {
        mCallbackManager = CallbackManager.Factory.create();
        facebookButton.setReadPermissions("email", "public_profile");
        facebookButton.registerCallback(mCallbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                Log.e(TAG, "Facebook:onSuccess: " + loginResult);
                handleFacebookAccessToken(loginResult.getAccessToken());
            }

            @Override
            public void onCancel() {
                Log.e(TAG, "facebook:onCancel");
            }

            @Override
            public void onError(FacebookException error) {
                Log.e(TAG, "facebook:onError", error);
            }
        });
    }

    private void setClickListener() {
        signup.setOnClickListener(this);
        login.setOnClickListener(this);
        phoneAuth.setOnClickListener(this);
    }

    public void init() {
        progressDialog = new ProgressDialog(this);
        mAuth = FirebaseAuth.getInstance();
    }


    private boolean checkConnection() {
        boolean isConnected = ConnectivityReceiver.isConnected();
        showNetworkStatus(isConnected);
        return true;
    }

    @Override
    public void onStart() {
        super.onStart();
        currentUser = mAuth.getCurrentUser();
        if (currentUser != null) {
            updateUI();
        }
    }

    private void updateUI() {
        startActivity(new Intent(StartActivity.this, MainActivity.class));
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Pass the activity result back to the Facebook SDK
        mCallbackManager.onActivityResult(requestCode, resultCode, data);
    }

    private void handleFacebookAccessToken(AccessToken token) {
        AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            FirebaseUser user = mAuth.getCurrentUser();
                            updateUI();
                        } else {
                            Toast.makeText(StartActivity.this, "Authentication failed.",
                                    Toast.LENGTH_SHORT).show();
                        }

                    }
                });
    }

    @Override
    public void onClick(View view) {
        int id = view.getId();
        Intent intent;
        switch (id) {
            case R.id.signup:
                intent = new Intent(StartActivity.this, RegisterActivity.class);
                startActivity(intent);
                break;

            case R.id.login:
                intent = new Intent(StartActivity.this, LoginActivity.class);
                startActivity(intent);
                break;

            case R.id.phoneAuth:
                intent = new Intent(StartActivity.this, PhoneAuthActivity.class);
                startActivity(intent);
                break;
        }
    }

    private void showNetworkStatus(boolean isConnected) {
        String message = "";
        int color = 0;
        if (isConnected) {
            progressDialog.dismiss();
            message = "Connected to Internet";
            color = Color.WHITE;
            Snackbar snackbar = Snackbar
                    .make(relativeLayout, message, Snackbar.LENGTH_LONG);

            View sbView = snackbar.getView();
            TextView textView = sbView.findViewById(android.support.design.R.id.snackbar_text);
            textView.setTextColor(color);
            snackbar.show();
        } else {
            progressDialog.setTitle(getResources().getString(R.string.check_connection));
            progressDialog.setMessage(getResources().getString(R.string.wait));
            progressDialog.setCancelable(false);
            progressDialog.show();
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        LapitChat.getInstance().setConnectivityListener(this);
    }

    @Override
    public void onNetworkConnectionChanged(boolean isConnected) {
        showNetworkStatus(isConnected);
    }
}

Answer 1

如果你想在不重新启动应用程序的情况下了解互联网状态，你应该使用广播接收器
Broadcasts overview