android - 每次 Activity 访问时显示布局

Question

您好，我的目标是在我访问的每个 Activity 中显示包含视频的布局对于我的聊天应用程序，但这可能吗？

如果是，请指导我实现它的方法，谢谢。

我知道如果我使用 fragment 是可能的，但我们目前的应用程序方法使用了很多 Activity

Answer 1

第 1 步:将 android.permission.SYSTEM_ALERT_WINDOW 权限添加到 AndroidManifest.xml 文件。此权限允许应用创建窗口，显示在所有其他应用之上。

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

第 2 步:创建要显示的聊天头像的布局。

 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="65dp"
    android:id="@+id/chat_head_root"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <!--Profile image for the chat head.-->
    <ImageView
        android:id="@+id/chat_head_profile_iv"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_marginTop="8dp"
        android:src="@drawable/ic_android_circle"
        tools:ignore="ContentDescription"/>

    <!--Close button-->
    <ImageView
        android:id="@+id/close_btn"
        android:layout_width="26dp"
        android:layout_height="26dp"
        android:layout_marginLeft="40dp"
        android:src="@drawable/ic_close"
        tools:ignore="ContentDescription"/>
</RelativeLayout>

现在创建一个名为 ChatHeadService 的服务。每当你想显示聊天头像时，使用 startService() 命令启动服务。在服务的 onCreate() 中，我们将在窗口的左上角添加聊天头像的布局。

要随着用户的触摸拖动聊天头，我们必须重写 OnTouchListener()。并实现 onclick 以停止服务。

服务等级

import android.app.Service;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.os.IBinder;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;

public class ChatHeadService extends Service {

    private WindowManager mWindowManager;
    private View mChatHeadView;

    public ChatHeadService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        //Inflate the chat head layout we created
        mChatHeadView = LayoutInflater.from(this).inflate(R.layout.layout_chat_head, null);

        //Add the view to the window.
        final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);

        //Specify the chat head position
        params.gravity = Gravity.TOP | Gravity.LEFT;        //Initially view will be added to top-left corner
        params.x = 0;
        params.y = 100;

        //Add the view to the window
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mWindowManager.addView(mChatHeadView, params);

        //Set the close button.
        ImageView closeButton = (ImageView) mChatHeadView.findViewById(R.id.close_btn);
        closeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //close the service and remove the chat head from the window
                stopSelf();
            }
        });

        //Drag and move chat head using user's touch action.
        final ImageView chatHeadImage = (ImageView) mChatHeadView.findViewById(R.id.chat_head_profile_iv);
        chatHeadImage.setOnTouchListener(new View.OnTouchListener() {
            private int lastAction;
            private int initialX;
            private int initialY;
            private float initialTouchX;
            private float initialTouchY;

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:

                        //remember the initial position.
                        initialX = params.x;
                        initialY = params.y;

                        //get the touch location
                        initialTouchX = event.getRawX();
                        initialTouchY = event.getRawY();

                        lastAction = event.getAction();
                        return true;
                    case MotionEvent.ACTION_UP:
                        //As we implemented on touch listener with ACTION_MOVE,
                        //we have to check if the previous action was ACTION_DOWN
                        //to identify if the user clicked the view or not.
                        if (lastAction == MotionEvent.ACTION_DOWN) {
                            //Open the chat conversation click.
                            Intent intent = new Intent(ChatHeadService.this, ChatActivity.class);
                            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            startActivity(intent);

                            //close the service and remove the chat heads
                            stopSelf();
                        }
                        lastAction = event.getAction();
                        return true;
                    case MotionEvent.ACTION_MOVE:
                        //Calculate the X and Y coordinates of the view.
                        params.x = initialX + (int) (event.getRawX() - initialTouchX);
                        params.y = initialY + (int) (event.getRawY() - initialTouchY);

                        //Update the layout with new X & Y coordinate
                        mWindowManager.updateViewLayout(mChatHeadView, params);
                        lastAction = event.getAction();
                        return true;
                }
                return false;
            }
        });
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mChatHeadView != null) mWindowManager.removeView(mChatHeadView);
    }
}

示例 Activity

import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.Settings;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private static final int CODE_DRAW_OVER_OTHER_APP_PERMISSION = 2084;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Check if the application has draw over other apps permission or not?
        //This permission is by default available for API<23. But for API > 23
        //you have to ask for the permission in runtime.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !Settings.canDrawOverlays(this)) {

            //If the draw over permission is not available open the settings screen
            //to grant the permission.
            Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
                    Uri.parse("package:" + getPackageName()));
            startActivityForResult(intent, CODE_DRAW_OVER_OTHER_APP_PERMISSION);
        } else {
            initializeView();
        }
    }

    /**
     * Set and initialize the view elements.
     */
    private void initializeView() {
        findViewById(R.id.notify_me).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startService(new Intent(MainActivity.this, ChatHeadService.class));
                finish();// comment this if you want your activity not to close.
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == CODE_DRAW_OVER_OTHER_APP_PERMISSION) {

            //Check if the permission is granted or not.
            if (resultCode == RESULT_OK) {
                initializeView();
            } else { //Permission is not available
                Toast.makeText(this,
                        "Draw over other app permission not available. Closing the application",
                        Toast.LENGTH_SHORT).show();

                finish();
            }
        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }
}