Android基础--ConnectivityManager检查网络连接

PrimaryActivity.java

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.util.TypedValue;
import android.view.Menu;
import android.view.MenuItem;

/**
* Created by JKerving on 2015/11/25.
*/
public class PrimaryActivity extends AppCompatActivity {
public static final String TAG = "Basic Network Demo";

private static boolean wifiConnected = false;

private static boolean mobileConnected = false;

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

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);//这里使用toolbar，放弃使用actionbar
setSupportActionBar(toolbar);

SimpleTextFragment fragment = (SimpleTextFragment)      getFragmentManager().findFragmentById(R.id.intro_fragment);//界面显示使用Fragment，使得我们的UI更易管理，自从Fragment问世以来我们就应当更加频繁的使用Fragment
fragment.setText(R.string.intro_message);
fragment.getTextView().setTextSize(TypedValue.COMPLEX_UNIT_DIP,16.0f);

}

@Override
public boolean onCreateOptionsMenu(Menu menu){
getMenuInflater().inflate(R.menu.menu_main,menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item){
switch (item.getItemId()){
case R.id.test_action:
checkNetworkConnection();
return true;
case R.id.clear_action:
return true;
}
return false;
}

private void checkNetworkConnection() {
ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeInfo = connMgr.getActiveNetworkInfo();
if (activeInfo != null && activeInfo.isConnected()){
wifiConnected = activeInfo.getType() == ConnectivityManager.TYPE_WIFI;
mobileConnected = activeInfo.getType() == ConnectivityManager.TYPE_MOBILE;

if (wifiConnected){
Log.i(TAG,getString(R.string.wifi_connection));
}else if (mobileConnected){
Log.i(TAG,getString(R.string.mobile_connection));
}
}else {
Log.i(TAG,getString(R.string.no_wifi_or_mobile));
}
}
}

SimpleTextFragment.java

import android.app.Fragment;
import android.os.Bundle;

import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

/**
* Created by JKerving on 2015/11/25.
*/
public class SimpleTextFragment extends Fragment {
String mText;

int mTextId = -1;

public static final String TEXT_KEY = "text";
public static final String TEXT_ID_KEY = "text_id";

private TextView mTextView;

public SimpleTextFragment(){}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
//Initialize the variables by using getArguments in Fragment
//Fragment中的变量我们应当尽可能的使用setArgument与getArgument方法来进行初始化
if (getArguments() != null){
Bundle args = getArguments();
if (args.containsKey(TEXT_KEY)){
mText = args.getString(TEXT_KEY);
Log.d("Constructors","Initialize Text");
}else if (args.containsKey(TEXT_ID_KEY)){
mTextId = args.getInt(TEXT_ID_KEY);
mText = getString(mTextId);
Log.d("Constructors","Initialize TextID and Text");
}
}else {
Toast.makeText(getActivity(),"getAruments is null",Toast.LENGTH_SHORT).show();
}

mTextView = new TextView(getActivity());
mTextView.setGravity(Gravity.CENTER);

if (mText != null){
mTextView.setText(mText);
}

return mTextView;
}

public TextView getTextView(){
return mTextView;
}

public void setText(int stringId){
getTextView().setText(getActivity().getString(stringId));
}
}

布局文件

primary_layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.v7.widget.Toolbar android:id="@+id/toolbar"
android:layout_width="match_parent" android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" app:popupTheme="@style/AppTheme.PopupOverlay" />

<fragment
android:name="com.example.jkerving.basicnetwork.SimpleTextFragment"
android:id="@+id/intro_fragment"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="@android:color/darker_gray"/>

</LinearLayout>

在写这个程序的过程中，遇到了一些小问题。

Error：

java.lang.SecurityException: ConnectivityService: Neither user 10063 nor current process has android.permission.ACCESS_NETWORK_STATE.

观察错误发现是由于没有在AndroidManifest.xml中声明取得网络状态的权限，只要加上以下权限即可正常运行：

uses-permission android:name=”android.permission.ACCESS_NETWORK_STATE”