我有一个WebView正在从互联网加载一个页面。我想显示一个ProgressBar,直到加载完成。
我如何监听WebView页面加载的完成?
我有一个WebView正在从互联网加载一个页面。我想显示一个ProgressBar,直到加载完成。
我如何监听WebView页面加载的完成?
当前回答
只是为了显示进度条,“onpagstarted”和“onPageFinished”方法就足够了;但如果你想有一个“is_loading”标志(以及页面重定向,…),这个方法可以执行非排序,如“onpagstarted > onpagstarted > onPageFinished > onPageFinished”队列。
但与我的短测试(自己测试),“onProgressChanged”方法值队列是“0-100 > 0-100 > 0-100 >…”
private boolean is_loading = false;
webView.setWebChromeClient(new MyWebChromeClient(context));
private final class MyWebChromeClient extends WebChromeClient{
@Override
public void onProgressChanged(WebView view, int newProgress) {
if (newProgress == 0){
is_loading = true;
} else if (newProgress == 100){
is_loading = false;
}
super.onProgressChanged(view, newProgress);
}
}
如果活动关闭是一个静态变量,也要在活动关闭时设置“is_loading = false”,因为活动可以在页面结束之前完成。
其他回答
你可以通过webview类中的getProgress方法来跟踪进度状态。
初始化进度状态
private int mProgressStatus = 0;
然后AsyncTask像这样加载:
private class Task_News_ArticleView extends AsyncTask<Void, Void, Void> {
private final ProgressDialog dialog = new ProgressDialog(
your_class.this);
// can use UI thread here
protected void onPreExecute() {
this.dialog.setMessage("Loading...");
this.dialog.setCancelable(false);
this.dialog.show();
}
@Override
protected Void doInBackground(Void... params) {
try {
while (mProgressStatus < 100) {
mProgressStatus = webview.getProgress();
}
} catch (Exception e) {
}
return null;
}
protected void onPostExecute(Void result) {
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
}
}
使用setWebViewClient()并重写onPageFinished()
我发现了一个优雅的解决方案,虽然没有严格测试:
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
if (webView.getProgress() == 100) {
progressBar.setVisibility(View.GONE);
webView.setVisibility(View.VISIBLE);
}
}
谢谢你的回答。它帮助了我,但我必须根据我的需要稍加改进。我有几个页面开始和结束,所以我添加了一个定时器,检查是否在页面结束后开始一个新的页面开始。好吧,糟糕的解释。请参阅代码:)
myWebView.setWebViewClient(new WebViewClient() {
boolean loadingFinished = true;
boolean redirect = false;
long last_page_start;
long now;
// Load the url
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (!loadingFinished) {
redirect = true;
}
loadingFinished = false;
view.loadUrl(url);
return false;
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
Log.i("p","pagestart");
loadingFinished = false;
last_page_start = System.nanoTime();
show_splash();
}
// When finish loading page
public void onPageFinished(WebView view, String url) {
Log.i("p","pagefinish");
if(!redirect){
loadingFinished = true;
}
//call remove_splash in 500 miSec
if(loadingFinished && !redirect){
now = System.nanoTime();
new android.os.Handler().postDelayed(
new Runnable() {
public void run() {
remove_splash();
}
},
500);
} else{
redirect = false;
}
}
private void show_splash() {
if(myWebView.getVisibility() == View.VISIBLE) {
myWebView.setVisibility(View.GONE);
myWebView_splash.setVisibility(View.VISIBLE);
}
}
//if a new "page start" was fired dont remove splash screen
private void remove_splash() {
if (last_page_start < now) {
myWebView.setVisibility(View.VISIBLE);
myWebView_splash.setVisibility(View.GONE);
}
}
});
加载url与swiperfreshlayout和ProgressBar: UrlPageActivity.java:
WebView webView;
SwipeRefreshLayout _swipe_procesbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_url_page);
String url = "http://stackoverflow.com/";
_swipe_procesbar = (SwipeRefreshLayout)findViewById(R.id.url_path_swipe_procesbar);
_swipe_procesbar.post(new Runnable() {
@Override
public void run() {
_swipe_procesbar.setRefreshing(true);
}
}
);
webView = (WebView) findViewById(R.id.url_page_web_view);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
_swipe_procesbar.setRefreshing(false);
_swipe_procesbar.setEnabled(false);
}
});
webView.loadUrl(url);
}
activity_url_page.xml:
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/url_path_swipe_procesbar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.test.test1.UrlPageActivity">
<WebView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/url_page_web_view" />
</RelativeLayout>
</android.support.v4.widget.SwipeRefreshLayout>