仅在启动屏幕消失后才加载应用程序

Question

应用启动时，我会看到启动屏幕及其3秒钟（应在3秒钟后加载该应用），但是当启动屏幕消失时，该应用开始加载

我的初始屏幕：

public class SplashActivity extends AppCompatActivity {
    final  int splashDuration=3000;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent mainIntent=new Intent(SplashActivity.this,MainActivity.class);
                SplashActivity.this.startActivity(mainIntent);
                SplashActivity.this.finish();
            }
        },splashDuration);
    }
}

清单：

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".SplashActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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