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?
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
上面的答案很好,但我想补充一些其他的东西。我是Android的新手,我在开发过程中遇到了这些问题。希望这能帮助到像我这样的人。
The Splash screen is the entry point of my app, so add the following lines in AndroidManifest.xml. <activity android:name=".SplashActivity" android:theme="@android:style/Theme.DeviceDefault.Light.NoActionBar"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> The splash screen should only show once in the app life cycle, I use a boolean variable to record the state of the splash screen, and only show it on the first time. public class SplashActivity extends Activity { private static boolean splashLoaded = false; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (!splashLoaded) { setContentView(R.layout.activity_splash); int secondsDelayed = 1; new Handler().postDelayed(new Runnable() { public void run() { startActivity(new Intent(SplashActivity.this, MainActivity.class)); finish(); } }, secondsDelayed * 500); splashLoaded = true; } else { Intent goToMainActivity = new Intent(SplashActivity.this, MainActivity.class); goToMainActivity.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT); startActivity(goToMainActivity); finish(); } } }
编码快乐!
其他回答
我在android中使用线程制作Flash屏幕。
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
public class HomeScreen extends AppCompatActivity{
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.screen_home);
Thread thread = new Thread(){
public void run(){
try {
Thread.sleep(3 * 1000);
Intent i = new Intent(HomeScreen.this, MainActivity.class);
startActivity(i);
} catch (InterruptedException e) {
}
}
};
thread.start();
}
}
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。
Create an activity: Splash Create a layout XML file: splash.xml Put UI components in the splash.xml layout so it looks how you want your Splash.java may look like this: public class Splash extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.splash); int secondsDelayed = 1; new Handler().postDelayed(new Runnable() { public void run() { startActivity(new Intent(Splash.this, ActivityB.class)); finish(); } }, secondsDelayed * 1000); } } change ActivityB.class to whichever activity you want to start after the splash screen check your manifest file and it should look like
<活动 android: name = "。屏” android: label = " @string / app_name " > > < /活动 <活动 android: name = "。飞溅” android: label = " @string / title_activity_splash_screen " > <意图过滤器> <action android:name="android.intent.action. main " /> <category android:name="android.intent.category. launcher " /> < /意图过滤器> > < /活动
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;
}
}
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一种方法是通过创建FullScreenActivity/EmptyActivity(例如SplashScreenActivity),并将其设置为打开应用程序时显示的第一个活动。在AndroidManifest.xml中添加以下内容到您的活动
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
然后,您可以设置一个处理程序,在几秒钟后取消此活动。
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
Intent i= new Intent(SplashScreenActivity.this,MainActivity.class);
startActivity(i); //start new activity
finish();
}
}, 3000); //time in milliseconds
其次,如果你不想创建一个单独的活动,你可以在MainActivity上膨胀一个布局,并将布局可见性设置为GONE,或者在几毫秒后在现有的启动画面布局上膨胀主布局。