您可以使用下面的代码。

getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN); 
getWindow().setStatusBarColor(Color.TRANSPARENT);

将此布局包含在主布局中。

toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/toolbarNav"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/transparent"
        app:contentInsetEnd="0dp"
        app:contentInsetLeft="0dp"
        app:contentInsetRight="0dp"
        app:contentInsetStart="0dp">

        <RelativeLayout
            android:id="@+id/rlBackImageLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/main_background2">  //add your color here

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="@dimen/_40sdp"
                android:layout_marginTop="@dimen/_16sdp"
                android:orientation="horizontal">

                <ImageView
                    android:id="@+id/toolbarIcon"
                    android:layout_width="@dimen/_30sdp"
                    android:layout_height="@dimen/_30sdp"
                    android:layout_gravity="center"
                    android:layout_marginStart="@dimen/_10sdp"
                    android:padding="@dimen/_5sdp"
                    android:src="@drawable/nav_icon" />

                <TextView
                    android:id="@+id/txtTitle"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_gravity="center"
                    android:layout_marginEnd="@dimen/_30sdp"
                    android:fontFamily="@font/muli_semibold"
                    android:gravity="center"
                    android:textColor="#fff"
                    android:textSize="@dimen/_14ssp"
                    android:textStyle="bold"
                    tools:text="test Data" />

            </LinearLayout>

        </RelativeLayout>

    </androidx.appcompat.widget.Toolbar>

注:可以用dp代替SDP，用sp代替SSP。

在你的XML中使用这段代码，你将能够在你的活动中看到时间条:

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

下面的代码将创建一个完全透明的状态栏:

package com.demo;

import android.app.Activity;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

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

        if (Build.VERSION.SDK_INT >= 19 && Build.VERSION.SDK_INT < 21) {
            setWindowFlag(this, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, true);
        }
        if (Build.VERSION.SDK_INT >= 19) {
            getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
        }
        if (Build.VERSION.SDK_INT >= 21) {
            setWindowFlag(this, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, false);
            getWindow().setStatusBarColor(Color.TRANSPARENT);
        }
    }

    public static void setWindowFlag(Activity activity, final int bits, boolean on) {
        Window win = activity.getWindow();
        WindowManager.LayoutParams winParams = win.getAttributes();
        if (on) {
            winParams.flags |= bits;
        } else {
            winParams.flags &= ~bits;
        }
        win.setAttributes(winParams);
    }
}

只需将这行代码添加到你的主java文件中:

getWindow().setFlags(
    WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
    WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS
);

这是一个简单的方法，我找到了很多搜索。

步骤1

在你的主题里放这个项目

        <item name="android:statusBarColor" tools:targetApi="lollipop">@android:color/transparent</item>

步骤2

主要活动

WindowCompat.setDecorFitsSystemWindows(window, false)

非常重要，如果你使用底部导航栏

在一些设备中，API 30+ u会发现系统导航栏与底部导航栏重叠，如果在你的应用中使用它。

这就解决了这个问题。

  if (Build.VERSION.SDK_INT >= 30) {
        // Root ViewGroup of my activity
        val root = findViewById<ConstraintLayout>(R.id.root)

        ViewCompat.setOnApplyWindowInsetsListener(root) { view, windowInsets ->

            val insets = windowInsets.getInsets(WindowInsetsCompat.Type.systemBars())

            // Apply the insets as a margin to the view. Here the system is setting
            // only the bottom, left, and right dimensions, but apply whichever insets are
            // appropriate to your layout. You can also update the view padding
            // if that's more appropriate.

            view.layoutParams =  (view.layoutParams as FrameLayout.LayoutParams).apply {
                leftMargin = insets.left
                bottomMargin = insets.bottom
                rightMargin = insets.right
            }

            // Return CONSUMED if you don't want want the window insets to keep being
            // passed down to descendant views.
            WindowInsetsCompat.CONSUMED
        }

    }

试试下面的代码:

private static void setStatusBarTransparent(Activity activity) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
        activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
        activity.getWindow(). setStatusBarColor(Color.TRANSPARENT);
    } else {
        activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
    }
}