如何在加载android应用程序时删除白色屏幕？

Question

我是Android新手。我有一个加载URL的web视图。问题是，在我打开应用程序后，网页浏览器的URL被加载后，有2-3秒钟的白屏。

我认为这是应用程序启动的时间。如何移除白色屏幕并显示我的徽标？我听说过闪屏，但标志显示1秒，然后白色屏幕显示2-3秒，最后加载web视图。

我做错了什么？在加载web视图时，是否使用启动屏幕或其他方式显示徽标？

package com.exampe.dating;

import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.view.KeyEvent;
import android.view.Menu;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends Activity {

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

        WebView mywebview = (WebView) findViewById(R.id.webview);
         mywebview.loadUrl("http://www.example.com/mobile/index.php");
         WebSettings webSettings = mywebview.getSettings();
         webSettings.setJavaScriptEnabled(true);
         mywebview.setWebViewClient(new WebViewClient());
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        WebView mywebview = (WebView) findViewById(R.id.webview);
        if ((keyCode == KeyEvent.KEYCODE_BACK) && mywebview.canGoBack()) {
            mywebview.goBack();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
}

splashActivity.java

package com.exampe.dating;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.view.WindowManager;

public class SplashActivity extends Activity {

       private static String TAG = SplashActivity.class.getName();
       private static long SLEEP_TIME = 10;    // Sleep for some time

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

          this.requestWindowFeature(Window.FEATURE_NO_TITLE);    // Removes title bar
          this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);    // Removes notification bar

          setContentView(R.layout.splash);

          // Start timer and launch main activity
          IntentLauncher launcher = new IntentLauncher();
          launcher.start();
       }

       private class IntentLauncher extends Thread {
          @Override
          /**
           * Sleep for some time and than start new activity.
           */
          public void run() {
             try {
                // Sleeping
                Thread.sleep(SLEEP_TIME*1000);
             } catch (Exception e) {
                Log.e(TAG, e.getMessage());
             }

             // Start main activity
             Intent intent = new Intent(SplashActivity.this, MainActivity.class);
             SplashActivity.this.startActivity(intent);
             SplashActivity.this.finish();
          }
       }
    }

Android清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.exampe.dating"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET" /> 
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        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="com.exampe.dating.MainActivity"
            android:label="@string/app_name"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen"  >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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


    </application>

</manifest>

Answer 1

现在你正在显示一个飞溅，睡觉，然后在启动主活动的同时消除飞溅，这就是开始加载页面。飞溅-

你应该在闪屏显示时开始加载页面，并在页面加载后移除闪屏。

您可以覆盖

public void onPageFinished (WebView view, String url)

连接到您的WebView的WebViewClient，并使该方法消除splash。将splash作为一个对话框而不是一个活动可能更容易。

Answer 2

在你的清单中声明了两个发射活动，这很奇怪。您应该消除＜code＞SplashActivity

编辑更新以等待代替睡眠。加载页面或发生超时时，启动屏幕将消失，以先到者为准。

public class MainActivity extends Activity {
    public static Object SPLASH_LOCK = new Object();

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


        WebView mywebview = (WebView) findViewById(R.id.webview);
        mywebview.loadUrl("http://www.example.com/mobile/index.php");
        WebSettings webSettings = mywebview.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mywebview.setWebViewClient(new WebViewClient());

        startActivity(new Intent(this, SplashActivity.class));
    }
    . . .
}

// in your WebViewClient:
public void onPageFinished (WebView view, String url) {
    synchronized (SPLASH_LOCK) {
        SPLASH_LOCK.notifyAll();
    }
}    

然后在< code>SplashActivity中，等待您想要的延迟，然后调用< code>finish()。您不需要再次启动< code>MainActivity，因为它位于< code>SplashActivity之后，将在< code>SplashActivity完成时出现。

public class SplashActivity extends Activity {

       private static String TAG = SplashActivity.class.getName();
       private static long MAX_SPLASH_TIME = 10000;

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

          . . .

          setContentView(R.layout.splash);

          new Thread() {
              @Override
              public void run() {
                  synchronized (MainActivity.SPLASH_LOCK) {
                      // wait for notify or time-out
                      try { MainActivity.SPLASH_LOCK.wait(MAX_SPLASH_TIME); }
                      catch (InterruptedException ignored) {}
                  }
                  finish();
              }
          }.start();
       }
       . . .
}

请注意，您不需要IntentLauncher类。

附言：您没有询问此事，但是如果您将其添加到清单中的“闪闪活动”标记中：

android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

然后，您无需调用请求窗口功能或在“创建”中设置窗口标志。