android 第一更（判斷網絡狀態）

判斷網絡狀態 三種 沒有網絡 wifi網絡 GPRS網絡 這一章先寫頁面的判斷 明天開始加上服務和廣播 讓網絡判斷在後臺進行 讓程序隨時能監控網絡狀態。

上代碼

package getui.com.networkstatus;

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

/**
 * Created by yf on 2015/9/15.
 */
public class NetworkActivity extends Activity {
    Button btn;
    TextView tv;
    public static ConnectivityManager connectivityManager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btn = (Button) findViewById(R.id.btn);
        tv = (TextView) findViewById(R.id.tv);
         connectivityManager = (ConnectivityManager) this
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        if(checkNetworkState()){
             btn.setVisibility(View.VISIBLE);
        }else{
            btn.setVisibility(View.INVISIBLE);
            isNetworkAvailable();
        }
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = null;
                /**
                 * 判斷手機系統的版本！如果API大於10 就是3.0+ 因爲3.0以上的版本的設置和3.0以下的設置不一樣，調用的方法不同
                 */
                if (android.os.Build.VERSION.SDK_INT > 10) {
                    intent = new Intent(
                            android.provider.Settings.ACTION_WIFI_SETTINGS);
                } else {
                    intent = new Intent();
                    ComponentName component = new ComponentName(
                            "com.android.settings",
                            "com.android.settings.WirelessSettings");
                    intent.setComponent(component);
                    intent.setAction("android.intent.action.VIEW");
                }
                startActivity(intent);
            }
        });

    }
    private static boolean checkNetworkState() {
        NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();
        if (activeNetInfo == null||!activeNetInfo.isAvailable()) {
            return true;
        }
        return false;
    }
    /**
     * 網絡已經連接，然後去判斷是wifi連接還是GPRS連接 設置一些自己的邏輯調用
     */
    private void isNetworkAvailable() {

        NetworkInfo.State gprs = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)
                .getState();
        NetworkInfo.State wifi = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
                .getState();
        if (gprs == NetworkInfo.State.CONNECTED || gprs == NetworkInfo.State.CONNECTING) {
            Toast.makeText(this, "wifi is open! gprs", Toast.LENGTH_SHORT)
                    .show();
        }
        // 判斷爲wifi狀態下才加載廣告，如果是GPRS手機網絡則不加載！
        if (wifi == NetworkInfo.State.CONNECTED || wifi == NetworkInfo.State.CONNECTING) {
            Toast.makeText(this, "wifi is open! wifi", Toast.LENGTH_SHORT)
                    .show();
        }
    }
    @Override
    protected void onRestart() {//設置完成後返回到本頁面要進行再次判斷網絡狀態
        super.onRestart();
        checkNetworkState();
    }
}

main.xml文件

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
<Button
    android:id="@+id/btn"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:visibility="invisible"
    android:background="@null"
    android:text="設置網絡連接"/>
    <TextView
        android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="網絡連接狀態："/>
</LinearLayout>

因爲需要網絡 所以要添加網絡的權限

 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>