文章一:
首先在,AndroidManifest.xml 中增加访问权限:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
package com.example.yanlei.myapplication; import android.content.Context; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.Button; import android.widget.TextView; import java.text.SimpleDateFormat; import java.util.Date; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //手工增加代码开始 //将按钮绑定一个单操作的事件监听器。用于监听用户的单击操作。 Button button = (Button) findViewById(R.id.button2); button.setOnClickListener(myOnClickListener); } public static String getCurrentTime() { SimpleDateFormat df = new SimpleDateFormat("yyyy'年'MM'月'dd'日' HH:mm:ss"); return df.format(new Date()); } boolean checkNetwork() { // 实例化ConnectivityManager ConnectivityManager manager = (ConnectivityManager)this.getSystemService(Context.CONNECTIVITY_SERVICE); // 获得当前网络信息 NetworkInfo info = manager.getActiveNetworkInfo(); // 判断是否连接 if (info == null || !info.isConnected()) { return false; } return true; } //手动增加代码开始 private View.OnClickListener myOnClickListener = new View.OnClickListener() { public void onClick(View v) { //增加自己的代码...... // Button pButton = (Button) findViewById(R.id.button2); // pButton.setText("OnClick. " + "my 新"); /*Intent intent=new Intent(); intent.setComponent(new ComponentName("com.android.calendar", "com.android.calendar.LaunchActivity")); startActivity(intent);*/ TextView pTextView=(TextView)findViewById(R.id.textView2); String str=pTextView.getText().toString(); if (checkNetwork()) { pTextView.setText("已连上网"); } else { pTextView.setText("已连不上网"); } } }; //手动增加代码结束 }