Question

我的应用中的启动画面不显示。只显示白色背景。然后它进入下一页。我在stackoverflow中看到过其他类似的问题，但它对我没有帮助。 splash.xml：

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

</RelativeLayout>

代码：

public class Splash extends AppCompatActivity {
    @Override
    protected void onCreate( Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);
        Handler handler=new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent=new Intent(Splash.this,MainActivity.class);
                startActivity(intent);
                Splash.this.finish();
            }
        },2000);

    }
}

的Manifest.xml：

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

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

</manifest>

Answer 1

大尺寸图像时，您应该对图像进行缩减采样。根据需要更改inSampleSize变量值。增加值，会降低图像分辨率，反之亦然

    public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
                                                     int reqWidth, int reqHeight) {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeResource(res, resId, options);

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    return BitmapFactory.decodeResource(res, resId, options);
  }

private static int calculateInSampleSize(
        BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        final int halfHeight = height / 2;
        final int halfWidth = width / 2;

        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
        // height and width larger than the requested height and width.
        while ((halfHeight / inSampleSize) > reqHeight
                && (halfWidth / inSampleSize) > reqWidth) {
            inSampleSize *= 2;
        }
    }

    return inSampleSize;
}

调用以上方法，如下面的代码：

  decodeSampledBitmapFromResource(getResources(), R.drawable.splash, 400, 400);

只是，在您的公共帮助器类中添加上述方法并将其命名为

Answer 2

问题是我在创建启动画面时遇到的问题。您可以在活动的onCreate方法中启动处理程序。

根据android开发人员site：

当你创建一个新的Handler时，它被绑定到创建它的线程的线程/消息队列

所以你在主线程上创建一个处理程序，它也负责UI。这个线程准备你的UI（在这种情况下似乎需要2秒多一点）然后调用你的处理程序中的Runnable，它立即转移到另一个活动，因此你的启动没有显示。

那你能做什么？在显示视图后启动计时器!!!

这就是你如何做到的（可能不是唯一的方式，但足够好）：

1-在XML中设置RelativeLayout的id：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/splash">
</RelativeLayout>

2-你的onCreate方法是这样的：

public class Splash extends AppCompatActivity {
    @Override
    protected void onCreate( Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);
        View background = findViewById(R.id.background); // or use Butterknife or DataBinding for ease of use
        final Handler handler=new Handler();
        background.post(new Runnable() {
            @Override
            public void run() {
            handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent=new Intent(Splash.this,MainActivity.class);
                startActivity(intent);
                Splash.this.finish();
            }
        },2000);
            }
        });
    }
}

这样您就可以将消息发布到视图消息队列中，然后在视图放到屏幕上之后，它会根据需要注册一个处理程序。希望它有所帮助。

Answer 3

在这里，我试图解决你的问题

<强> splash_screen_activity.xml

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

</LinearLayout>

<强> SplashScreenActivity.java

public class SplashScreenActivity extends AppCompatActivity {

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

        Thread background = new Thread() {
            public void run() {

                try {
                    // Thread will sleep for 5 seconds
                    sleep(5*1000);

                    // After 5 seconds redirect to another intent
                    Intent i=new Intent(getBaseContext(),MainActivity.class);
                    startActivity(i);

                    //Remove activity
                    finish();

                } catch (Exception e) {

                }
            }
        };

        // start thread
        background.start();
    }
}

<强>的manifest.xml

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

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

</manifest>

Android Splash屏幕无法显示

3 个答案: