在WebView中添加进度条

Question

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">

    <WebView  xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/webview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

    <TextView  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/hello" />
</LinearLayout>

Answer 1

这个链接可以帮到你.

我在你的代码中添加了几行,现在它的进度条很好.

        getWindow().requestFeature(Window.FEATURE_PROGRESS);
        setContentView(R.layout.main );
        // Makes Progress bar Visible
        getWindow().setFeatureInt( Window.FEATURE_PROGRESS, Window.PROGRESS_VISIBILITY_ON);

        webview = (WebView) findViewById(R.id.webview);
        webview.setWebChromeClient(new WebChromeClient() {
            public void onProgressChanged(WebView view, int progress)   
            {
                //Make the bar disappear after URL is loaded, and changes string to Loading...
                setTitle("Loading...");
                setProgress(progress * 100); //Make the bar disappear after URL is loaded

                // Return the app name after finish loading
                if(progress == 100)
                   setTitle(R.string.app_name);
                }
            });
        webview.setWebViewClient(new HelloWebViewClient());
        webview.getSettings().setJavaScriptEnabled(true);
        webview.loadUrl("http://www.google.com");

Answer 2

在oncreate方法中,您已设置Webview.

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.web_view);

web_view = (WebView) findViewById(R.id.web_view);
pd = new ProgressDialog(SiteOpenInWebView.this);
    pd.setMessage("Please wait Loading...");
    pd.show();
    web_view.setWebViewClient(new MyWebViewClient());
    web_view.loadUrl("ur site name");
 }

WebViewClient

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

    if (!pd.isShowing()) {
        pd.show();
    }

    return true;
}

@Override
public void onPageFinished(WebView view, String url) {
    System.out.println("on finish");
    if (pd.isShowing()) {
        pd.dismiss();
    }

  }
}

Answer 3

通过此方法传递您的网址

private void startWebView(String url) {

        WebSettings settings = webView.getSettings();

        settings.setJavaScriptEnabled(true);
        webView.setScrollBarStyle(View.SCROLLBARS_OUTSIDE_OVERLAY);

        webView.getSettings().setBuiltInZoomControls(true);
        webView.getSettings().setUseWideViewPort(true);
        webView.getSettings().setLoadWithOverviewMode(true);

        progressDialog = new ProgressDialog(ContestActivity.this);
        progressDialog.setMessage("Loading...");
        progressDialog.show();

        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                if (progressDialog.isShowing()) {
                    progressDialog.dismiss();
                }
            }

            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                Toast.makeText(ContestActivity.this, "Error:" + description, Toast.LENGTH_SHORT).show();

            }
        });
        webView.loadUrl(url);
    }

Answer 4

将进度条和webview放在relativelayout中,并设置进度条的属性,如下所示,

1. 使其可见性为GONE.
2. 将它放在Relativelayout中.

然后在webclient的onPageStarted()中使进度条可见,以便在您单击链接时显示进度条.在onPageFinished()中,将进度条可见性设置为GONE,以便在页面加载完成后消失...这将适用于您的场景.希望这可以帮助...

Answer 5

这是我正在使用的代码:

在WebViewClient中:

               @Override
             public void onPageStarted(WebView view, String url, Bitmap favicon) {

              super.onPageStarted(view, url, favicon);
              findViewById(R.id.progress1).setVisibility(View.VISIBLE);
             }

            @Override
            public void onPageFinished(WebView view, String url) {
                findViewById(R.id.progress1).setVisibility(View.GONE);
            }

这是XML:

<ProgressBar
    android:id="@+id/progress1"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

希望这可以帮助..

Answer 6

对我有用的最好的approch是

webView.setWebViewClient(new WebViewClient() {

    @Override public void onPageStarted(WebView view, String url, Bitmap favicon) {
          super.onPageStarted(view, url, favicon);
          mProgressBar.setVisibility(ProgressBar.VISIBLE);
          webView.setVisibility(View.INVISIBLE);
        }

    @Override public void onPageCommitVisible(WebView view, String url) {
      super.onPageCommitVisible(view, url);
      mProgressBar.setVisibility(ProgressBar.GONE);
      webView.setVisibility(View.VISIBLE);
      isWebViewLoadingFirstPage=false;
    }
}