Android 開發網路判斷，有網路自動載入網路資料，沒有網路時顯示容錯頁和一個警示條，類似於QQ介面的警示條
QQ介面沒有網路時顯示

一.寫個工具類，獲取手機是否有網路並獲取網路型別

//判斷網路連線狀態
    public static boolean isNetWorkConnect(Context context) {
        if (context != null) {
            ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = manager.getActiveNetworkInfo();
            if
 
 (networkInfo != null) {
                return networkInfo.isAvailable();
            }
        }
        return false;
    }

    //判斷wifi連線
    public static boolean isWifiConnect(Context context) {
        if (context != null) {
            ConnectivityManager manager = (ConnectivityManager)  context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
            if
 
 (networkInfo != null) {
                return networkInfo.isAvailable();
            }
        }
        return false;
    }

    //判斷行動網路
    public static boolean isMobileConnect(Context context) {
        if (context != null) {
            ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
            if
 
 (networkInfo != null) {
                return networkInfo.isAvailable();
            }
        }
        return false;
    }

    //獲取連線型別
    public static int connectType(Context context) {
        if (context != null) {
            ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = manager.getActiveNetworkInfo();
            if (networkInfo != null && networkInfo.isAvailable()) {
                return networkInfo.getType();
            }
        }
        return -1;
    }

    //隱式跳轉設定網路
    public static void netWorkSetting(Context context) {
        if (context != null) {
            if (Build.VERSION.SDK_INT > 10) {
                context.startActivity(new Intent("android.settings.SETTINGS"));
                return;
            }
            context.startActivity(new Intent("android.settings.WIRELESS_SETTINGS"));
        }
    }
    //吐絲方法
    public static void showToast(Context context, String str) {
        Toast.makeText(context, str, Toast.LENGTH_SHORT).show();
    }

二.通過廣播獲取網路連線動作，然後通過一個介面回撥將網路連線狀態回撥到Activity

public class Receiver extends BroadcastReceiver {
    private CallBackNetWorkState callBackNetWorkState;

    public Receiver(CallBackNetWorkState callBackNetWorkState) {
        this.callBackNetWorkState = callBackNetWorkState;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) {
            boolean connect = Utils.isNetWorkConnect(context);
            if (connect) {
                Utils.showToast(context, "網路連線成功");
                if (callBackNetWorkState != null) {
                //有網路，介面回撥一個true
                    callBackNetWorkState.callBackState(true);
                }
            } else {
                if (callBackNetWorkState != null) {
                       //沒有網路，介面回撥一個false
                    callBackNetWorkState.callBackState(false);
                }
                Utils.showToast(context, "網路連接出錯");
            }
        }
    }
}

MainActivity介面拿到回撥結果

//實現CallBackData 介面，拿到返回資料
public class MainActivity extends AppCompatActivity implements  CallBackData,CallBackNetWorkState{
//抓取的一個拼多多的介面
String url = "http://apiv3.yangkeduo.com/v4/goods?page=1&size=20&list_id=0410536007&pdduid=";
  @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initReceiver();
        initView();
    }
        private void initView() {
        //初始化控制元件
        viewShow = (LinearLayout) findViewById(R.id.view_show);
        lv = (ListView) findViewById(R.id.lv);
        error = (LinearLayout) findViewById(R.id.error);
    }
      //執行廣播
      public void initReceiver() {
        receiver = new Receiver(this);
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(receiver, intentFilter);
    }
       private void initData() {
        //類名呼叫靜態方法，執行網路請求
        NetUtils net = new NetUtils(this);
        net.requestNetWork(url);
    }
     //將網路是否連線的狀態返回回來，並執行警示條顯示邏輯
     @Override
    public void callBackState(boolean state) {
        if (viewShow != null) {
            viewShow.setVisibility(state ? View.GONE : View.VISIBLE);
            if (state) {
                initData();
                lv.setVisibility(View.VISIBLE);
                error.setVisibility(View.GONE);
            } else {
                error.setVisibility(View.VISIBLE);
                lv.setVisibility(View.GONE);
            }
            viewShow.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Utils.netWorkSetting(MainActivity.this);
                }
            });
        }
    }
    //介面銷燬不要忘了登出廣播
    @Override
    protected void onDestroy() {
        unregisterReceiver(receiver);
        super.onDestroy();
    }
      //一個呼叫網路請求的方法
        private void initData() {
        //呼叫網路請求方法
        NetUtils net = new NetUtils(this);
        net.requestNetWork(url);
    }
    //這是一個網路請求通過介面返回的資料
     @Override
    public void callBackData(Object responseBean) {
        //介面返回請求的資料
        if (responseBean != null) {
            final ResponseBean bean = (ResponseBean) responseBean;
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    if (adapter == null) {
                        Log.e("TAG", "handler+adapter");
                        adapter = new MyListViewAdapter(bean.goods_list, MainActivity.this);
                        lv.setAdapter(adapter);
                    } else {
                        adapter.notifyDataSetChanged();
                    }
                }
            });
        }
    }
    }

網路請求的一個簡單工具類,Ok請求資料

public class NetUtils {
    private CallBackData callBackData;

    public NetUtils(CallBackData callBackData) {
        this.callBackData = callBackData;
    }

    /**
     *
     * @param url
     * ok非同步請求網路，請求資料也是通過介面回撥到activity介面
     */
    public void requestNetWork(String url) {
        OkHttpClient mOkHttpClient = new OkHttpClient.Builder()
                .build();
        Request mRequest = new Request.Builder()
                .url(url)
                .get()
                .build();
        Call call = mOkHttpClient.newCall(mRequest);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                callBackData.callBackData(null);
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                //將請求成功的結果通過介面回撥給activity
                if (response != null && response.isSuccessful()) {
                    ResponseBean data = ResponseBean.objectFromData(response.body().string());
                    callBackData.callBackData(data);
                }
            }
        });
    }

}

三.介面卡和介面

public class MyListViewAdapter extends BaseAdapter {
    private List<ResponseBean.GoodsListBean> list;
    private Context context;

    public MyListViewAdapter(List<ResponseBean.GoodsListBean> list, Context context) {
        this.list = list;
        this.context = context;
    }

    @Override
    public int getCount() {
        return list != null ? list.size() : 0;
    }

    @Override
    public Object getItem(int i) {
        return list != null ? list.get(i) : 0;
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        MyViewHolder myViewHolder;
        if (view == null) {
            myViewHolder = new MyViewHolder();
            view = view.inflate(context, R.layout.itemlist_layout, null);
            myViewHolder.tv = view.findViewById(R.id.tv);
            myViewHolder.iv = view.findViewById(R.id.iv);
            view.setTag(myViewHolder);
        } else {
            myViewHolder = (MyViewHolder) view.getTag();
        }
        myViewHolder.tv.setText(list.get(i).goods_name);
        //顯示佔位圖和容錯圖
        RequestOptions options = new RequestOptions()
                .placeholder(R.mipmap.ic_launcher)
                .error(R.mipmap.ic_launcher);
        Glide.with(context).load(list.get(i).image_url).apply(options).into(myViewHolder.iv);
        return view;
    }

    static class MyViewHolder {
        TextView tv;
        ImageView iv;
    }
}
兩個介面類
public interface CallBackData<T> {
    void callBackData(T t);
}
public interface CallBackNetWorkState {
    void callBackState(boolean state);
}

執行結果顯示

Demo下載地址 http://download.csdn.net/download/te_small/10021174