Question

我在我的应用程序中添加了启动画面，我的代码如下所示：

public class SplashActivity extends AppCompatActivity {

    public static final int DELAY_MILLIS = 2000;//for testing i use 5 seconds
    private Handler handler = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent = new Intent(SplashActivity.this, CurrencyExchangeActivity.class);
                startActivity(intent);
                finish();
            }
        }, DELAY_MILLIS);
    }

    @Override
    protected void onStop() {
        super.onStop();
        handler.removeCallbacksAndMessages(null);
    }
}

我的宣言：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.vdovin.currencyratesapp">

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:name=".application.CurrencyApp"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity
            android:name=".screens.splash.SplashActivity"
            android:theme="@style/SplashTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

        <activity android:name=".screens.main.CurrencyExchangeActivity">
        </activity>
    </application>
</manifest>

所以我遇到了下一个问题：

如果我在加载启动画面时使用主页按钮隐藏我的应用程序，那么当我再次打开应用程序时，启动屏幕活动不会调用CurrencyExchangeActivity。我知道它出现是因为方法onCreate()仅调用一次，但我无法将其放入onResume()，因为当我再次打开我的应用时，它再次向我显示启动画面。但我想展示CurrencyActivity，就像谷歌的应用程序（地图，工作表等......）

Answer 1

请尝试这种方式。我还没有测试过您的代码。我对使用启动的影响如下：

public class SplashActivity extends Activity {
private static final String TAG = SplashActivity.class.getSimpleName();
Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        loadNext();
    }
};

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


    new Thread() {
        @Override
        public void run() {
            try {
                sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            handler.sendEmptyMessage(1);
        }
    }.start();
}


protected void loadNext() {
    Intent intent = new Intent(this, NextActivity.class);
    startActivity(intent);
    finish();
}
}

Answer 2

你忘了添加

setContentView(R.layout.splash);

添加它将起作用

Answer 3

也许您可以尝试以下方法：

@Override
protected void onResume() {
    super.onResume();
    Intent intent = new Intent(this, CurrencyExchangeActivity.class);
    startActivity(intent);
    finish();
}

按下主页按钮后重新打开应用程序时会跳过此延迟。

Answer 4

我通常使用postDelayed Runnable。

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private Handler handler = new Handler();

    private Runnable runnable = new Runnable() {
        @Override
        public void run() {
            Intent intent = new Intent(this, NextActivity.class);
            startActivity(intent);
            finish();
        }
    };

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


    }

    @Override
    protected void onResume() {
        super.onResume();
        // 5 sec
        handler.postDelayed(runnable, 5000);
    }

    @Override
    protected void onPause() {
        super.onPause();
        // 5 sec
        handler.removeCallbacks(runnable);
    }
}

Answer 5

您不能这样做只是因为您将启动画面图像设置为background theme的{{1}}。这是窗口级别的背景，无论您的导航或任何东西都会出现。

如果你真的想在应用生命周期中只显示一次启动画面，那么你必须在Activity中执行此操作并将该图像作为布局的一部分，并使用not the right way来扩充该布局。现在当你再次进入应用时，你会在setContentView CurrencyExchangeActivity setContentView之前调用splash activity，这只会显示黑色窗口背景并直接显示CurrencyExchangeActivity。

让我知道这是否有意义。如果需要，我可以详细说明

Answer 6

我建议在您的案例中保持启动屏幕显示机制CurrencyActivity。这是伪代码。

我在代码中添加了适当的注释。请检查。

public class CurrencyActivity extends AppCompatActivity {

    public static final int DELAY_MILLIS = 2000; //for testing i use 5 seconds
    private Handler handler = null;
    private boolean showSplash = true; // True by default
    private ImageView splashImage;

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

        // Get a image overlaying the other views in your currency layout
        splashImage = (ImageView) findViewById(R.id.splash);

        if(showSplash) showSplashScreen();
    }

    @Override
    protected void onStop() {
        super.onStop();
        handler.removeCallbacksAndMessages(null);
    }

    @Override
    protected void onPause() {
        super.onPause();
        showSplash = false; // Set the variable to false when you take this in background
    }

    @Override
    protected void onResume() {
        super.onResume();
        // Check if the variable is false and then set the visibility to GONE
        if(!showSplash) splashImage.setVisibility(View.GONE);
    }

    private void showSplashScreen() {
        handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                splashImage.setVisibility(View.GONE);
                showSplash = false;
            }
        }, DELAY_MILLIS);
    }
}

Answer 7

试试这个 -

SplashScreenActivity -

public class SplashActivity extends AppCompatActivity {

public static final int DELAY_MILLIS = 2000;//for testing i use 5 seconds

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

    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            Intent intent = new Intent(SplashActivity.this, CurrencyExchangeActivity.class);
            startActivity(intent);
            finish();
        }
    }, DELAY_MILLIS);
}

}

对于清单 -

<?xml version="1.0" encoding="utf-8"?>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    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=".CurrencyExchangeActivity"/>




</application>

我测试了这段代码，如果您遇到的问题是当按下主屏幕按钮时会再次显示启动画面，那么这将有效....

启动画面活动

7 个答案: