Android的双屏异显
最近在做超市收银系统,需要双屏异显,全局设置客户屏显示内容,做一下笔记。
1.客户屏:继承Presentation
public class CustomerDisplay extends Presentation { private Context mContext; public CustomerDisplay(Context outerContext, Display display) { super(outerContext,display); protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); setContentView(R.layout.view_display_customer); tv = findViewById(R.id.tv); public void setProductList(String str){ public void setAdvertisement(){
2.客户屏工具类
需要注意的是传入的Context为getApplicationContext(),否则不能全局双屏异显,只能在一个界面中双屏显示
public class CustomerEngine { private DisplayManager mDisplayManager;// 屏幕管理器 private Display[] displays;// 屏幕数组 private CustomerDisplay mCustomerDisplay; //(继承Presentation) private static CustomerEngine instance; * @param context 这里需要传入getApplicationContext(),就能实现全局双屏异显 public static CustomerEngine getInstance(Context context){ instance = new CustomerEngine(context); public static void colose(){ private CustomerEngine(Context context){ mDisplayManager = (DisplayManager) context.getSystemService(Context.DISPLAY_SERVICE); displays = mDisplayManager.getDisplays(); if (null == mCustomerDisplay && displays.length > 1) { mCustomerDisplay = new CustomerDisplay(context, displays[1]);// displays[1]是副屏 mCustomerDisplay.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); public void setProductList(String str){ if(mCustomerDisplay != null){ mCustomerDisplay.setProductList(str);
3.主屏
这里需要注意的是退出时需要完成退出应用,否则不能取消双屏异显
public class MainActivity extends AppCompatActivity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); setCustomerProductList(); private void setCustomerProductList(){ CustomerEngine.getInstance(getApplicationContext()).setProductList("测试一下吧"); public void onBackPressed() { Intent startMain = new Intent(Intent.ACTION_MAIN); startMain.addCategory(Intent.CATEGORY_HOME); startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); startActivity(startMain);
4.对了,别忘了加权限
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/> <uses-permission android:name="android.permission.SYSTEM_OVERLAY_WINDOW" />
好了,这样就能实现全局双屏异显了。
这里是完整的demo
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