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
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();
}
}
其他回答
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。
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
Create an Activity SplashScreen.java public class SplashScreen extends Activity { protected boolean _active = true; protected int _splashTime = 3000; // time to display the splash screen in ms @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.splashscreen); Thread splashTread = new Thread() { @Override public void run() { try { int waited = 0; while (_active && (waited < _splashTime)) { sleep(100); if (_active) { waited += 100; } } } catch (Exception e) { } finally { startActivity(new Intent(SplashScreen.this, MainActivity.class)); finish(); } }; }; splashTread.start(); } } splashscreen.xml will be like this <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="600px" android:layout_height="1024px" android:background="#FF0000"> </RelativeLayout>
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!
在Android中,启动画面是一个有点不可用的对象:为了隐藏主活动启动的延迟,它不能尽快加载。使用它有两个原因:广告和网络运营。
实现为对话框使跳跃没有延迟从启动画面到主UI的活动。
public class SplashDialog extends Dialog {
ImageView splashscreen;
SplashLoader loader;
int splashTime = 4000;
public SplashDialog(Context context, int theme) {
super(context, theme);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
setCancelable(false);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
cancel();
}
}, splashTime);
}
}
布局:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@color/white">
<ImageView
android:id="@+id/splashscreen"
android:layout_width="190dp"
android:layout_height="190dp"
android:background="@drawable/whistle"
android:layout_centerInParent="true" />
</RelativeLayout>
并开始:
public class MyActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getIntent().getCategories() != null && getIntent().getCategories().contains("android.intent.category.LAUNCHER")) {
showSplashScreen();
}
}
protected Dialog splashDialog;
protected void showSplashScreen() {
splashDialog = new SplashDialog(this, R.style.SplashScreen);
splashDialog.show();
}
...
}