Android-activity-intent

 package com.hanqi.myapplication;

 import android.content.ComponentName;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.util.Log;
 import android.view.View;
 import android.widget.Button;

 public class MainActivity extends AppCompatActivity {

     //回调方法 （on开头的方法都是）
     //在创建时自动调用
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         //调用父类的回调方法
         super.onCreate(savedInstanceState);
         //设置内容视图文件
         //建立Activity和Layout文件之间的关联
         setContentView(R.layout.test_linearlayout);
         //1.获得这个组件
         Button bt2 =  (Button)findViewById(R.id.button2);
         //2.操作这个组件
        // bt2.setText("新按钮");
         //日志输出
         System.out.print("日志输出=应用开始运行");
         Log.v("HANQI", "Verbose级别的日志信息");
         Log.d("HANQI", "Debug级别的日志信息");
         Log.i("HANQI", "Info级别的日志信息");
         Log.w("HANQI", "Warning级别的日志信息");
         Log.e("HANQI", "Error级别的日志信息");
     }
     public void login_onClick(View v)
     {
         //打开新的Activity
         //1.创建意图  显式意图
         Intent intent = new Intent();
         //定义显式意图
         ComponentName componentName = new ComponentName(this,TextActivity.class);
         intent.setComponent(componentName);
         intent.putExtra("name", "意图传递的值");
         intent.putExtra("name1", "意图传递的值1");

         //2.发起意图
       startActivity(intent);
     }
     public void bt2_onClick(View v)
     {
         //发起隐式意图
         //打开拨打电话的界面
         //系统已经预先定义了常用功能的Action的字符串常量
         Intent intent2 = new Intent(Intent.ACTION_DIAL);
         //intent2.setAction(Intent.ACTION_DIAL);

         //构造Uri
         Uri uri = Uri.parse("tel:110");

         //intent2.addCategory("");

         //设置data
         intent2.setData(uri);

         //intent2.setType("");
         //intent2.setDataAndType(uri,"");
         startActivity(intent2);
     }

     public void bt3_onClick(View v)
     {
         //返回桌面
         Intent intent3 = new Intent(Intent.ACTION_MAIN);
         intent3.addCategory(Intent.CATEGORY_HOME);
         startActivity(intent3);
     }
 }

 package com.hanqi.myapplication;

 import android.app.Activity;
 import android.content.Intent;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.widget.EditText;
 import android.widget.Toast;

 //1.继承Activity
 /**
  * Created by lenovo on 2016/4/22.
  */
 public class TextActivity extends Activity {

     //成员变量
     EditText et1;
     EditText et2;
     EditText et3;
     //2.重写onCreate(),关联Layout文件
     //onCreate()是一个回调方法：在满足特定条件下自动调用的方法；方法名一般on开头

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         //关联
         setContentView(R.layout.message_relativelayout);
         //初始化工作
         //获取Layout文件中定义的组件

         et1=(EditText)findViewById(R.id.et1);
         et2=(EditText)findViewById(R.id.et2);
         et3=(EditText)findViewById(R.id.et3);
         Log.e("TAG","onCreat()被调用");

         //得到意图
         Intent intent = getIntent();
         String strname = intent.getStringExtra("name");
         String strname1 = intent.getStringExtra("name1");
         //intent.getExtras();
         Log.e("TAG","意图传递的数据="+strname);
         Log.e("TAG","意图传递的数据1="+strname1);
 //        if(savedInstanceState!=null&&!savedInstanceState.isEmpty())
 //        {
 //        et1.setText(savedInstanceState.getString("et1")+"恢复之后的");
 //        et2.setText(savedInstanceState.getString("et2"));
 //        et3.setText(savedInstanceState.getString("et3"));
 //        }
     }

     //保存状态
     @Override
     protected void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
         Log.e("TAG", "保存应用状态");

         outState.putString("et1", et1.getText().toString());
         outState.putString("et1",et2.getText().toString());
         outState.putString("et1",et3.getText().toString());
     }

     //恢复状态
     @Override
     protected void onRestoreInstanceState(Bundle savedInstanceState) {
         super.onRestoreInstanceState(savedInstanceState);
         Log.e("TAG", "恢复应用状态");

         et1.setText(savedInstanceState.getString("et1")+"恢复之后的");
         et2.setText(savedInstanceState.getString("et2"));
         et3.setText(savedInstanceState.getString("et3"));

     }

     //启动
     @Override
     protected void onStart() {
         super.onStart();
         Log.e("TAG","onStart()被调用");
     }
     //重启
     @Override
     protected void onRestart() {
         super.onRestart();
         Log.e("TAG", "onRestart()被调用");
     }
     //继续
     @Override
     protected void onResume() {
         super.onResume();
         Log.e("TAG", "onResume()被调用");
     }
     //暂停
     @Override
     protected void onPause() {
         super.onPause();
         Log.e("TAG", "onPause()被调用");
     }
     //停止
     @Override
     protected void onStop() {
         super.onStop();
         Log.e("TAG", "onStop()被调用");
     }
     //销毁
     @Override
     protected void onDestroy() {
         super.onDestroy();
         Log.e("TAG", "onDestroy()被调用");
     }
     //点击事件方法
     public void bt_OnClick(View v)
     {
         //显示提示信息
         //方法链
         Toast.makeText(TextActivity.this, "消息发送成功", Toast.LENGTH_SHORT).show();
     }
     public void close_OnClick(View v)
     {
         //关闭应用
         finish();
     }
 }

 <?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"
     android:padding="10dp">

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content">
         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="用户名："/>
     <EditText
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:hint="请输入用户名"/>
         </LinearLayout>
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content">
         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="密码："/>
     <EditText
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:hint="请输入密码"
         android:inputType="textPassword"
         android:maxLength="6"/>
         </LinearLayout>

 <LinearLayout
     android:layout_width="match_parent"
     android:layout_height="wrap_content">
     <Button
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:text="显式意图"
         android:id="@+id/button"
         android:layout_weight="1"
         android:onClick="login_onClick"/>

     <Button
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:text="隐式意图"
         android:id="@+id/button3"
         android:layout_weight="1"
         android:onClick="bt2_onClick"/>
     <Button
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:text="返回桌面"
         android:id="@+id/button4"
         android:layout_weight="1"
         android:onClick="bt3_onClick"/>

     <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="New Button"
         android:id="@+id/button2"
         android:layout_gravity="center"
         android:textSize="20sp"
         android:textColor="@color/colorPrimary"
         android:background="@drawable/anniu05"
         android:visibility="gone"/>
 </LinearLayout>
 </LinearLayout>

 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.hanqi.myapplication">

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

     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">

         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
         <activity android:name=".TextActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>

     </application>

 </manifest>