背景:

车载操作系统，现在的折叠屏手机，已经售货机等，都会需要有多屏异显的功能

具体代码实现

添加显示到第二屏需要的代码

package com.mine.myapplication;

import android.app.Presentation;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.Display;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class DifferentDislay extends Presentation {
    public DifferentDislay(Context outerContext, Display display) {
        super(outerContext,display);
        //TODOAuto-generated constructor stub
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.diffrentdisplay);
        Button btn = (Button)this.findViewById(R.id.button);
        TextView tv = (TextView) this.findViewById(R.id.textView);

        btn.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                tv.setText("hello different display");
            }
        });
    }
}

第二屏显示需要额外的权限

添加mainfest 权限

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

该显示的权限需要显式的进行声明

        if (!Settings.canDrawOverlays(this)) {
            Intent intent = new Intent();
            intent.setAction(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
            startActivity(intent);
        }

调用代码显示第二屏的内容

        DisplayManager mDisplayManager = (DisplayManager)MainActivity.this.getSystemService(Context.DISPLAY_SERVICE);
        Display[] displays = mDisplayManager.getDisplays();
        DifferentDislay mPresentation =new DifferentDislay (getApplicationContext(), displays[1]);//displays[1]是副屏
        mPresentation.getWindow().setType(WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY);
        mPresentation.show();