相关疑难解决方法(0)

我在这里看了一个类似的问题,但是因为我是一个新手,有人可以解释如何让它在WebView中工作,或至少如何设置10秒的时间延迟让人们知道它正在加载？

我正在尝试向我的应用程序添加进度/加载栏WebView.我很困惑如何实现每次单击链接时出现的进度条.

当前代码:

public class CULearnBrowser extends Activity {

    WebView webview;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        webview = (WebView) findViewById(R.id.webview);
        webview.setWebViewClient(new HelloWebViewClient());
        webview.getSettings().setJavaScriptEnabled(true);
        webview.loadUrl("https://culearn.colorado.edu/webct/entryPageIns.dowebct");
    }

    private class HelloWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    }

    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) {
            webview.goBack();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
}

活动布局:

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"> …

参考这个WebView教程,特别是这个方法

private void setupWebView(){
    String MAP_URL = "http://gmaps-samples.googlecode.com/svn/trunk/articles-android-webmap/simple-android-map.html";
    String centerURL = "javascript:centerAt(" + mostRecentLocation.getLatitude() + ","+ mostRecentLocation.getLongitude()+ ")";
    webView = (WebView) findViewById(R.id.webview);
    webView.getSettings().setJavaScriptEnabled(true);
    //Wait for the page to load then send the location information
    webView.setWebViewClient(new WebViewClient(){
        @Override
        public void onPageFinished(WebView view, String url){
            webView.loadUrl(centerURL);
        }
    });
    webView.loadUrl(MAP_URL);
}

我注意到如果我像这样webView.loadUrl(centerURL);直接 放置webView.loadUrl(MAP_URL);

private void setupWebView(){
    String MAP_URL = "http://gmaps-samples.googlecode.com/svn/trunk/articles-android-webmap/simple-android-map.html";
    String centerURL = "javascript:centerAt(" + mostRecentLocation.getLatitude() + "," + mostRecentLocation.getLongitude()+ ")";
    webView = (WebView) findViewById(R.id.webview);
    webView.getSettings().setJavaScriptEnabled(true);
    //Wait for …