<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent">
<EditText
android:id="@+id/account"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center_vertical"/>
两个界面布局
布局一 登录界面
<?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"> <LinearLayout android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="60dp"> <TextView android:layout_width="90dp" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:textSize="18sp" android:text="Account:" /> <EditText android:id="@+id/account" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:layout_gravity="center_vertical"/> </LinearLayout> <LinearLayout android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="60dp"> <TextView android:layout_width="90dp" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:textSize="18sp" android:text="Password:" /> <EditText android:id="@+id/password" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:layout_gravity="center_vertical" android:inputType="textPassword" /> </LinearLayout> <LinearLayout android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="wrap_content"> <CheckBox android:id="@+id/remember_pass" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="18sp" android:text="Remember password" /> </LinearLayout> <Button android:id="@+id/login" android:layout_width="match_parent" android:layout_height="60dp" android:text="Login" /> </LinearLayout>
布局二
主界面
<?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/force_offline" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Send force offline broadcast" /> </LinearLayout>
登录界面主活动
package com.example.broadcastbestpractice; import android.content.Intent; import android.content.SharedPreferences; import android.preference.PreferenceManager; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Toast; public class LoginActivity extends BaseActivity { private SharedPreferences pref; private SharedPreferences.Editor editor; private EditText accountEdit; private EditText passwordEdit; private Button login; private CheckBox rememberPass; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_login);// 打开登陆布局 // 读取信息 pref = PreferenceManager.getDefaultSharedPreferences(this); // 按键 编辑框ID accountEdit = (EditText) findViewById(R.id.account); passwordEdit = (EditText) findViewById(R.id.password); rememberPass = (CheckBox) findViewById(R.id.remember_pass); login = (Button) findViewById(R.id.login); // 设置 可选按钮 否 boolean isRemember = pref.getBoolean("remember_password", false); if (isRemember) { // 将账号和密码 读取到文本框中 String account = pref.getString("account", ""); String password = pref.getString("password", ""); accountEdit.setText(account); passwordEdit.setText(password); rememberPass.setChecked(true); } // 登陆 按键函数 login.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String account = accountEdit.getText().toString(); String password = passwordEdit.getText().toString(); // 如果账号是admin且密码是123456,就认为登录成功 if (account.equals("admin") && password.equals("123456")) { editor = pref.edit(); if (rememberPass.isChecked()) { // 检查复选框是否被选中 editor.putBoolean("remember_password", true); editor.putString("account", account); editor.putString("password", password); } else { editor.clear(); } editor.apply();// 执行储存 Intent intent = new Intent(LoginActivity.this, MainActivity.class); //打开下个主界面 startActivity(intent);//开始 finish();//销毁当前 } else { Toast.makeText(LoginActivity.this, "account or password is invalid", Toast.LENGTH_SHORT).show(); } } }); } }
主界面活动
package com.example.broadcastbestpractice; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; public class MainActivity extends BaseActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button forceOffline = (Button) findViewById(R.id.force_offline); forceOffline.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent("com.example.broadcastbestpractice.FORCE_OFFLINE"); sendBroadcast(intent); } }); } }
需要注册两个界面的关系
1 登录界面是主界面,自动启动
2 主界面是登陆界面,直接传递打开
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.broadcastbestpractice"> <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"> </activity> <activity android:name=".LoginActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
登录界面和主界面都继承了,重写了生成和销毁记录
BaseActivity类,里面添加了功能,能够很快管理所有的活动。例如销毁和生成
BaseActivity
package com.example.broadcastbestpractice; import android.app.AlertDialog; import android.content.BroadcastReceiver; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.IntentFilter; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; public class BaseActivity extends AppCompatActivity { private ForceOfflineReceiver receiver; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ActivityCollector.addActivity(this); } @Override protected void onResume() { super.onResume(); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction("com.example.broadcastbestpractice.FORCE_OFFLINE"); receiver = new ForceOfflineReceiver(); registerReceiver(receiver, intentFilter); } @Override protected void onPause() { super.onPause(); if (receiver != null) { unregisterReceiver(receiver); receiver = null; } } @Override protected void onDestroy() { super.onDestroy(); ActivityCollector.removeActivity(this); } class ForceOfflineReceiver extends BroadcastReceiver { @Override public void onReceive(final Context context, Intent intent) { AlertDialog.Builder builder = new AlertDialog.Builder(context); builder.setTitle("Warning"); builder.setMessage("You are forced to be offline. Please try to login again."); builder.setCancelable(false); builder.setPositiveButton("OK", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { ActivityCollector.finishAll(); // 销毁所有活动 Intent intent = new Intent(context, LoginActivity.class); context.startActivity(intent); // 重新启动LoginActivity } }); builder.show(); } } }
ActivityCollector
package com.example.broadcastbestpractice; import android.app.Activity; import java.util.ArrayList; import java.util.List; public class ActivityCollector { public static List<Activity> activities = new ArrayList<>(); public static void addActivity(Activity activity) { activities.add(activity); } public static void removeActivity(Activity activity) { activities.remove(activity); } public static void finishAll() { for (Activity activity : activities) { if (!activity.isFinishing()) { activity.finish(); } } } }