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

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

其他回答

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

有时用户打开SplashActivity并立即退出,但应用程序仍然在SPLASH_SCREEN_DISPLAY_LENGTH后转到MainActivity。

为了防止它:在SplashActivity中,你应该在移动到MainActivity之前检查SplashActivity是否结束

public class SplashActivity extends Activity {

    private final int SPLASH_SCREEN_DISPLAY_LENGTH = 2000;

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

                if (!isFinishing()) {//isFinishing(): If the activity is finishing, returns true; else returns false.
                    startActivity(new Intent(SplashActivity.this, MainActivity.class));
                    finish();
                }

            }, SPLASH_SCREEN_DISPLAY_LENGTH);
        }                             
   }                                
}

希望这对你有所帮助

你可以在你的onCreate方法中添加这个

new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    // going to next activity
                    Intent i=new Intent(SplashScreenActivity.this,MainActivity.class);
                    startActivity(i);
                    finish();
                }
            },time);

初始化你的时间值在毫秒,因为你想…

private  static int time=5000;

欲了解更多详细信息,请从此链接下载完整代码…

https://github.com/Mr-Perfectt/Splash-Screen

它真的很简单,在安卓,我们只是使用处理器的概念来实现启动画面

在SplashScreenActivity java文件中粘贴此代码。

在SplashScreenActivity xml文件中使用imageview放置任何图片。

public void LoadScreen() {
        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {                 
                Intent i = new Intent(SplashScreenActivity.this, AgilanbuGameOptionsActivity.class);
                startActivity(i);
            }
        }, 2000);
    }

另一种方法是使用CountDownTimer实现

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

 new CountDownTimer(5000, 1000) { //5 seconds
      public void onTick(long millisUntilFinished) {
          mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
      }

     public void onFinish() {
          startActivity(new Intent(SplashActivity.this, MainActivity.class));
          finish();
     }

  }.start();
}