如何在android中将url加载到webview时显示进度？

how to display progress while loading a url to webview in android?

提问by sai

I am loading url into webview:

我正在将 url 加载到 webview 中：

WebView webview=(WebView)findViewById(R.id.webview); 
webview.loadUrl(url);

It's taking some time to load url, during which it shows a blank screen. I want to display a progress dialog while the url is loading:

加载 url 需要一些时间，在此期间它显示一个空白屏幕。我想在加载 url 时显示进度对话框：

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

However, the above is code is not working. If any have any ideas, please help. Thanks in advance.

但是，上面的代码不起作用。如果有任何想法，请帮助。提前致谢。

回答by K_Anas

set a WebViewClientto your WebView, start your progress dialog on you onCreate()method an dismiss it when the page has finished loading in onPageFinished(WebView view, String url)

将 a 设置WebViewClient为您的 WebView，在您的onCreate()方法上启动您的进度对话框，并在页面加载完成后关闭它onPageFinished(WebView view, String url)

import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

public class Main extends Activity {
    private WebView webview;
    private static final String TAG = "Main";
    private ProgressDialog progressBar;  

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.main);

        this.webview = (WebView)findViewById(R.id.webview);

        WebSettings settings = webview.getSettings();
        settings.setJavaScriptEnabled(true);
        webview.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);

        final AlertDialog alertDialog = new AlertDialog.Builder(this).create();

        progressBar = ProgressDialog.show(Main.this, "WebView Example", "Loading...");

        webview.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                Log.i(TAG, "Processing webview url click...");
                view.loadUrl(url);
                return true;
            }

            public void onPageFinished(WebView view, String url) {
                Log.i(TAG, "Finished loading URL: " +url);
                if (progressBar.isShowing()) {
                    progressBar.dismiss();
                }
            }

            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                Log.e(TAG, "Error: " + description);
                Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show();
                alertDialog.setTitle("Error");
                alertDialog.setMessage(description);
                alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        return;
                    }
                });
                alertDialog.show();
            }
        });
        webview.loadUrl("http://www.google.com");
    }
}

your main.xml layout

你的 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>

回答by Mukund Samant

You will have to over ride onPageStarted and onPageFinished callbacks

您将不得不过度使用 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();
        }
    });

回答by Md Abdul Gafur

Check out the sample code. It help you.

查看示例代码。它可以帮助你。

 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);
    }
}

Thanks.

谢谢。

回答by Tim

You need to set an own WebViewClient for your WebView by extending the WebViewClientclass.

您需要通过扩展WebViewClient类为您的 WebView 设置自己的WebViewClient。

You need to implement the two methods onPageStarted (show here) and onPageFinished (dismiss here).

您需要实现两个方法 onPageStarted（此处显示）和 onPageFinished（此处关闭）。

More guidance for this topic can be found in Google's WebView tutorial

有关此主题的更多指导可以在 Google 的WebView 教程中找到

回答by john

  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();
    }
});