android系統開機畫面_Android開機畫面

android系統開機畫面

Android Splash Screen is the first screen visible to the user when the application’s launched. Splash screen is one of the most vital screens in the application since it’s the user’s first experience with the application.

Android啟動畫面是啟動應用程序時用戶可見的第一個屏幕。 閃屏是應用程序中最重要的屏幕之一,因為它是用戶對應用程序的首次體驗。

Splash screens are used to display some animations (typically of the application logo) and illustrations while some data for the next screens are fetched.

啟動屏幕用于顯示某些動畫(通常是應用程序徽標)和插圖,同時獲取下一個屏幕的一些數據。

Android開機畫面 (Android Splash Screen)

Typically, the Activity that has the following intent filter set in the AndroidManifest.xml file is the Splash Activity.

通常,在AndroidManifest.xml文件中設置了以下意圖過濾器的Activity是Splash Activity。

<intent-filter>            <action android:name="android.intent.action.MAIN" />            <category android:name="android.intent.category.LAUNCHER" />        </intent-filter>

Android啟動畫面示例項目結構 (Android Splash Screen Example Project Structure)

There are few ways to create the initial screen i.e. Splash Screen of the application. Let’s see each of them.

有幾種創建初始屏幕的方法,即應用程序的啟動屏幕。 讓我們看看它們中的每一個。

閃屏經典方法 (Splash Screen Classical Approach)

SplashActivity.java

package com.journaldev.splashscreen;import android.content.Intent;import android.os.Handler;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;public class SplashActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_splash);        new Handler().postDelayed(new Runnable() {            @Override            public void run() {                // This method will be executed once the timer is over                Intent i = new Intent(SplashActivity.this, MainActivity.class);                startActivity(i);                finish();            }        }, 5000);    }}

This is how we normally create the layout of our Splash Screen in our application: activity_splash.xml

通常,這就是我們在應用程序中創建啟動畫面布局的方式: activity_splash.xml

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:andro    xmlns:app="https://schemas.android.com/apk/res-auto"    xmlns:tools="https://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@android:color/black"    tools:context="com.journaldev.splashscreen.SplashActivity">    <ImageView        android:        android:layout_width="72dp"        android:layout_height="72dp"        android:src="@mipmap/ic_launcher"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintLeft_toLeftOf="parent"        app:layout_constraintRight_toRightOf="parent"        app:layout_constraintTop_toTopOf="parent" />    <ProgressBar        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:indeterminate="true"        app:layout_constraintLeft_toLeftOf="parent"        app:layout_constraintRight_toRightOf="parent"        android:layout_marginTop="8dp"        app:layout_constraintTop_toBottomOf="@id/imageView" /></android.support.constraint.ConstraintLayout>

Let’s keep the MainActivity.java empty for now.

讓我們MainActivity.java保持MainActivity.java空。

The output produced from the above implementation of SplashScreen is given below. We’ve set the theme of the SplashActivity to Theme.AppCompat.NoActionBar in the AndroidManifest.xml file.

下面是上述SplashScreen的實現所產生的輸出。 我們設置了SplashActivity到Theme.AppCompat.NoActionBar在主題AndroidManifest.xml文件。

Did you see the blank page that came up before the Splash Screen was visible to you?

在啟動畫面可見之前,您是否看到空白頁面?

The above approach isn’t the correct approach. It’ll give rise to cold starts.

上面的方法不是正確的方法。 它會引起冷啟動 。

The purpose of a Splash Screen is to quickly display a beautiful screen while the application fetches the relevant content if any (from network calls/database). With the above approach, there’s an additional overhead that the SplashActivity uses to create its layout.

啟動屏幕的目的是在應用程序獲取相關內容(從網絡調用/數據庫)中獲取相關內容時,快速顯示漂亮的屏幕。 使用上述方法, SplashActivity使用額外的開銷來創建其布局。

It’ll give rise to slow starts to the application which is bad for the user experience (wherein a blank black/white screen appears).

它將導致應用程序啟動緩慢,這不利于用戶體驗(其中出現黑屏/白屏)。

帶有正確方法的Android啟動畫面示例 (Android Splash Screen Example with Correct Approach)

The cold start appears since the application takes time to load the layout file of the Splash Activity. So instead of creating the layout, we’ll use the power of the application theme to create our initial layout.

由于應用程序需要時間來加載Splash Activity的布局文件,因此出現冷啟動。 因此,我們將使用應用程序主題的功能來創建初始布局,而不是創建布局。

Application theme is instantiated before the layout is created. We’ll set a drawable inside the android:windowBackground attribute that’ll comprise of the Activity’s background and an icon using layer-list as shown below.

在創建布局之前,將實例化應用程序主題。 我們將在android:windowBackground屬性內設置一個drawable,該屬性android:windowBackground Activity的背景和使用layer-list的圖標組成,如下所示。

splash_background.xml

splash_background.xml

<?xml version="1.0" encoding="utf-8"?><layer-list xmlns:andro>    <item android:drawable="@android:color/black" />    <item>        <bitmap            android:gravity="center"            android:src="@mipmap/ic_launcher" />    </item></layer-list>

We’ll set the following style as the theme of the activity.

我們將以下樣式設置為活動的主題。

styles.xml

styles.xml

<style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">        <item name="android:windowBackground">@drawable/splash_background</item>    </style>

The SplashActivity.java file should look like this:

SplashActivity.java文件應如下所示:

package com.journaldev.splashscreen;import android.content.Intent;import android.os.Handler;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;public class SplashActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        new Handler().postDelayed(new Runnable() {            @Override            public void run() {                // This method will be executed once the timer is over                Intent i = new Intent(SplashActivity.this, MainActivity.class);                startActivity(i);                finish();            }        }, 5000);    }}

Note: the theme of the activity is set before anything else. Hence the above approach would give our app a quicker start.

注意:活動的主題設置在其他任何主題之前。 因此,以上方法將使我們的應用程序更快速地啟動。

Using the theme and removing the layout from the SplashActivity is the correct way to create a splash screen. This brings an end to android splash screen tutorial. You can download the final Android Splash Screen Project from the link below.

使用主題并從SplashActivity中刪除布局是創建初始屏幕的正確方法。 這結束了android啟動畫面教程。 您可以從下面的鏈接下載最終的Android Splash Screen Project。

Download Android Splash Screen Example Project 下載Android啟動畫面示例項目

翻譯自: https://www.journaldev.com/17831/android-splash-screen

android系統開機畫面

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