我想让我的应用看起来更专业,所以我决定添加一个启动画面。

我应该如何进行实现呢?


当前回答

这是完整的代码

SplashActivity.java

public class SplashActivity extends AppCompatActivity {

private final int SPLASH_DISPLAY_DURATION = 1000;

@Override
public void onCreate(Bundle bundle) {
    super.onCreate(bundle);


    new Handler().postDelayed(new Runnable(){
        @Override
        public void run() {

            Intent mainIntent = new Intent(SplashActivity.this,MainActivity.class);
            SplashActivity.this.startActivity(mainIntent);
            SplashActivity.this.finish();
        }
    }, SPLASH_DISPLAY_DURATION);
}}

在drawables中创建bg_splash.xml

<?xml version="1.0" encoding="utf-8"?><layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<item
    android:drawable="@color/app_color"/>

<item>
    <bitmap
        android:gravity="center"
        android:src="@drawable/ic_in_app_logo_big"/>
</item></layer-list>

在styles.xml中创建一个自定义主题

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

最后在AndroidManifest.xml中指定活动的主题

<activity
        android:name=".activities.SplashActivity"
        android:label="@string/app_name"
        android:screenOrientation="portrait"
        android:theme="@style/SplashTheme">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

欢呼。

其他回答

启动画面示例:

public class MainActivity extends Activity {
    private ImageView splashImageView;
    boolean splashloading = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        splashImageView = new ImageView(this);
        splashImageView.setScaleType(ScaleType.FIT_XY);
        splashImageView.setImageResource(R.drawable.ic_launcher);
        setContentView(splashImageView);
        splashloading = true;
        Handler h = new Handler();
        h.postDelayed(new Runnable() {
            public void run() {
                splashloading = false;
                setContentView(R.layout.activity_main);
            }

        }, 3000);

    }

}

以上所有的答案都非常好。但是存在内存泄漏的问题。 这个问题在Android社区通常被称为“泄露活动”。这到底是什么意思呢?

当配置发生变化时,比如方向变化,Android会销毁Activity并重新创建它。通常,垃圾收集器只会清除旧Activity实例的已分配内存,一切正常。

“泄漏一个活动”指的是垃圾收集器无法清除旧活动实例的已分配内存的情况,因为它被(强)引用于一个活动实例外的对象。每个Android应用程序都分配了特定数量的内存。当垃圾回收器不能释放未使用的内存时,应用程序的性能将逐渐下降,最终崩溃并出现OutOfMemory错误。

如何确定应用程序是否泄漏内存?最快的方法是在Android Studio中打开内存选项卡,并在改变方向时注意分配的内存。 如果分配的内存一直在增加而不减少,那么就有内存泄漏。

1.当用户改变方向时内存泄漏。

首先,你需要在布局资源splashscreen.xml文件中定义启动画面

启动画面活动的示例代码。

public class Splash extends Activity {
 // 1. Create a static nested class that extends Runnable to start the main Activity
    private static class StartMainActivityRunnable implements Runnable {
        // 2. Make sure we keep the source Activity as a WeakReference (more on that later)
        private WeakReference mActivity;

        private StartMainActivityRunnable(Activity activity) {
         mActivity = new WeakReference(activity);
        }

        @Override
        public void run() {
         // 3. Check that the reference is valid and execute the code
            if (mActivity.get() != null) {
             Activity activity = mActivity.get();
             Intent mainIntent = new Intent(activity, MainActivity.class);
             activity.startActivity(mainIntent);
             activity.finish();
            }
        }
    }

    /** Duration of wait **/
    private final int SPLASH_DISPLAY_LENGTH = 1000;

    // 4. Declare the Handler as a member variable
    private Handler mHandler = new Handler();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(icicle);
        setContentView(R.layout.splashscreen);

        // 5. Pass a new instance of StartMainActivityRunnable with reference to 'this'.
        mHandler.postDelayed(new StartMainActivityRunnable(this), SPLASH_DISPLAY_LENGTH);
    }

    // 6. Override onDestroy()
    @Override
    public void onDestroy() {
     // 7. Remove any delayed Runnable(s) and prevent them from executing.
     mHandler.removeCallbacksAndMessages(null);

     // 8. Eagerly clear mHandler allocated memory
     mHandler = null;
    }
}

欲了解更多信息,请点击此链接

这里有一个简单的!

~卢诺克斯

MainActivity.java

package com.example.splashscreen;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

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

splashscreen.java

package com.example.splashscreen;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;

public class splashscreen extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splashscreen);

        //Splash Screen duration
        int secondsDelayed = 1;
        new Handler().postDelayed(new Runnable() {
            public void run() {
                startActivity(new Intent(splashscreen.this, MainActivity.class));
                finish();
            }
        }, secondsDelayed * 3000);
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

splashscreen.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/splashlogo"

    />

splashlogo.png

splashlogo.png

GitHub

SplashScreen

在Kotlin中编写以下代码:-

 Handler().postDelayed({
            val mainIntent = Intent(this@SplashActivity, LoginActivity::class.java)
            startActivity(mainIntent)
            finish()
        }, 500)

希望这对你有所帮助,谢谢........

在我的例子中,我不想创建一个新的活动只是为了显示2秒的图像。当启动我的MainActivity,图像被加载到持有者使用毕加索,我知道这需要大约1秒的加载,所以我决定做以下在我的MainActivity OnCreate:

splashImage = (ImageView) findViewById(R.id.spllll);

    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);

    int secondsDelayed = 1;
    new Handler().postDelayed(new Runnable() {
        public void run() {
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
            splashImage.setVisibility(View.GONE);

        }
    }, secondsDelayed * 2000);

当启动应用程序时,发生的第一件事是显示ImageView,并通过将窗口标志设置为全屏来删除状态栏。然后我使用Handler运行2秒,2秒后我清除全屏标志,并设置ImageView的可见性为GONE。简单,简单,有效。