在Android中刷新Webview时显示旋转图标

Question

我想知道如何在Android的WebView中添加加载动画，当特定页面正在加载时。在我的应用程序中，我正在使用WebView。当我通过链接浏览页面时，我希望出现一种加载进度条或Android Spinner。这是我的WebView代码。

public class URLActivity extends Activity {

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_webview);

        WebView webView = (WebView)findViewById(R.id.webView);

        webView.setInitialScale(0);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setLoadWithOverviewMode(true);
        webView.getSettings().setUseWideViewPort(true);
        webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
        webView.setScrollbarFadingEnabled(false);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("http://www.eternalbs.com");

    }

}

- user3197977

Answer 1

完整测试过的工作演示

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class URLActivity extends Activity {

    private ProgressDialog progress;

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_webview);

        WebView webView = (WebView) findViewById(R.id.webView);
        webView.setInitialScale(0);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setLoadWithOverviewMode(true);
        webView.getSettings().setUseWideViewPort(true);
        webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
        webView.setScrollbarFadingEnabled(false);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("http://www.eternalbs.com");

        webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                if (newProgress > 0) {
                    showProgressDialog("Please Wait");
                }
                if (newProgress >= 100) {
                    hideProgressDialog();
                }
            }
        });

    }

    public void showProgressDialog(final String msg) {

        runOnUiThread(new Runnable() {
            public void run() {
                if (progress == null || !progress.isShowing()) {
                    progress = ProgressDialog.show(URLActivity.this, "", msg);
                }
            }
        });
    }

    public void hideProgressDialog() {
        runOnUiThread(new Runnable() {

            @Override
            public void run() {
                try {
                    if (progress.isShowing())
                        progress.dismiss();
                } catch (Throwable e) {

                }
            }
        });
    }

}

- Biraj Zalavadia

---

你好Biraj，谢谢你的回答。但是为什么在showProgressDialog和hideProgressDialog中要使用Runnable呢？ - Souhaib Guitouni

实际上，我把上述方法放在我的通用工具类中，可以从应用程序的任何位置调用。因此有时可能会从非UI线程调用方法。这就是为什么我使用runOnUiThread（）来防止应用程序崩溃。 - Biraj Zalavadia

Answer 2

尝试用这种方式：

final ProgressDialog pd = ProgressDialog.show(MainActivity.this, "", "Please wait, Loading page...", true);

        mWebview  = (WebView)findViewById(R.id.webView1);

            mWebview.getSettings().setJavaScriptEnabled(true); // enable javascript

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


            mWebview.setWebViewClient(new WebViewClient() {
                public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                    Toast.makeText(activity, description, Toast.LENGTH_SHORT).show();
                }

              @Override
              public void onPageStarted(WebView view, String url, Bitmap favicon)
              {
                  pd.show();
              }


                @Override
                public void onPageFinished(WebView view, String url) {
                    pd.dismiss();

                        String webUrl = mWebview.getUrl();

                        }

}

                 });

            mWebview .loadUrl("www.google.com");

- M D