如何在android中向webview加载url时显示进度?

如何在android中向webview加载url时显示进度?,android,webview,Android,Webview,我正在将url加载到webview中: WebView webview=(WebView)findViewById(R.id.webview); webview.loadUrl(url); 加载url需要一些时间,在此期间,它会显示一个空白屏幕。我想在加载url时显示进度对话框: ProgressDialog dialog = ProgressDialog.show(this, "HI","Loading......", true); 但是,上述代码不起作用。如果有任何想法,请帮助。提前谢

我正在将url加载到webview中:

WebView webview=(WebView)findViewById(R.id.webview); 
webview.loadUrl(url);
加载url需要一些时间,在此期间,它会显示一个空白屏幕。我想在加载url时显示进度对话框:

ProgressDialog dialog = ProgressDialog.show(this, "HI","Loading......", true);

但是,上述代码不起作用。如果有任何想法,请帮助。提前谢谢

您需要通过扩展类为您的WebView设置自己的WebViewClient

您需要实现onPageStarted(此处显示)和onPageFinished(此处取消)两种方法


有关此主题的更多指导可以在Google的中找到。将
WebViewClient
设置为您的WebView,在
onCreate()
方法上启动进度对话框,并在页面完成加载后在
onPageFinished(WebView视图,字符串url)

您的main.xml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 android:id="@string/webview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1" />
</LinearLayout>

查看示例代码。这对你有帮助

 private ProgressBar progressBar;
 progressBar=(ProgressBar)findViewById(R.id.webloadProgressBar);
 WebView urlWebView= new WebView(Context);
    urlWebView.setWebViewClient(new AppWebViewClients(progressBar));
                        urlWebView.getSettings().setJavaScriptEnabled(true);
                        urlWebView.loadUrl(detailView.getUrl());

public class AppWebViewClients extends WebViewClient {
     private ProgressBar progressBar;

    public AppWebViewClients(ProgressBar progressBar) {
        this.progressBar=progressBar;
        progressBar.setVisibility(View.VISIBLE);
    }
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        // TODO Auto-generated method stub
        view.loadUrl(url);
        return true;
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        // TODO Auto-generated method stub
        super.onPageFinished(view, url);
        progressBar.setVisibility(View.GONE);
    }
}

谢谢。

您将不得不使用onPageStarted和onPageFinished回调

mWebView.setWebViewClient(new WebViewClient() {

        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            if (progressBar!= null && progressBar.isShowing()) {
                progressBar.dismiss();
            }
            progressBar = ProgressDialog.show(WebViewActivity.this, "Application Name", "Loading...");
        }

        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);

            return true;
        }

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

        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            alertDialog.setTitle("Error");
            alertDialog.setMessage(description);
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    return;
                }
            });
            alertDialog.show();
        }
    });

将ProgressBar的可见性设置为GONE是错误的-视图必须被删除才能从视图堆栈中删除。感谢这个好例子,你救了我一天!可能重复:
mWebView.setWebViewClient(new WebViewClient() {

        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            if (progressBar!= null && progressBar.isShowing()) {
                progressBar.dismiss();
            }
            progressBar = ProgressDialog.show(WebViewActivity.this, "Application Name", "Loading...");
        }

        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);

            return true;
        }

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

        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            alertDialog.setTitle("Error");
            alertDialog.setMessage(description);
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    return;
                }
            });
            alertDialog.show();
        }
    });
  public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
        alertDialog.setTitle("Error");
        alertDialog.setMessage(description);
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                return;
            }
        });
        alertDialog.show();
    }
});