Android测试网络是否连接

一、布局页面

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.testnet.MainActivity" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/tstNetwrkBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp"
        android:text="@string/btnShow" />

</RelativeLayout>

二、编写Activity类

package com.example.testnet;

import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    private Button tstNetwrkBtn;
    private TextView tv1;
    private ConnectivityManager cm;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取button控件
        tstNetwrkBtn = (Button) findViewById(R.id.tstNetwrkBtn);
        context=this;

        //给button控件绑定单击事件
        tstNetwrkBtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                //获取Activity
                Activity c =(Activity)context;
                //获取TextView控件
                tv1 = (TextView)c.findViewById(R.id.textView1);

                //定义两个属性保存字符串和颜色
                String netStatus;
                int color;
                //获取网络连接对象
                cm=(ConnectivityManager) c.getSystemService(c.CONNECTIVITY_SERVICE);
                //获取网络连接状态
                NetworkInfo netInfo = cm.getActiveNetworkInfo();
                if (netInfo==null){
                    //网络连接失败时赋值文本内容和背景颜色
                    color = c.getResources().getColor(R.color.red);
                    netStatus = c.getResources().getString(R.string.netStatus0);
                }
                else{

                    //网络连接成功时赋值文本内容和背景颜色
                    netStatus = c.getResources().getString(R.string.netStatus1);
                    color = c.getResources().getColor(R.color.green);
                }

                //设置文本和背景颜色
                tv1.setText( netStatus  );
                tv1.setBackgroundColor(color);

            }
        });

    }

}

三、string文件和colors文件

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">testNet</string>
    <string name="hello_world">网络测试</string>
    <string name="btnShow">test Network</string>

    <string name="netStatus0">网络不正常</string>
    <string name="netStatus1">网络正常</string>

    <string name="action_settings">Settings</string>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<resources >

    <color name="red">#ff0000</color>
    <color name="green">#00ff00</color>
</resources>

四、权限(AndroidManifest.xml)

 <!-- 访问网络权限 -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

五、调试

网络正常时：

没网络时：