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
芬兰湾的科特林解决方案 第一个解决方案是创建webviewclient作为私有类,这是更有效的。 另一方面,第二个解决方案是sorter:)
第一个解决方案
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val webView : WebView = findViewById(R.id.webView)
webView.webViewClient = MyWebViewClient()
}
private class MyWebViewClient : WebViewClient() {
override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
println("Load Started")
}
override fun onPageFinished(view: WebView, url: String) {
println("Load Finished")
}
}
}
第二个解决方案
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val webView : WebView = findViewById(R.id.webView)
webView.webViewClient = object : WebViewClient() {
override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
println("Load Started")
}
override fun onPageFinished(view: WebView, url: String) {
println("Load Finished")
}
}
}
两个解其实是一样的。所以onpagstarted函数在页面开始加载时运行,另一个挂onPageFinished函数在页面完全加载时工作。你可能想在onPageFinished函数里面写一个loadFinishedRun()函数的例子。
迟到总比不到好
其他回答
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);
}
}
用这个应该会有帮助。' var currentUrl = "google.com" var partOfUrl = currentUrl。currentUrl.length-2 substring (0)
webView.setWebViewClient(object: WebViewClient() {
override fun onLoadResource(WebView view, String url) {
//call loadUrl() method here
// also check if url contains partOfUrl, if not load it differently.
if(url.contains(partOfUrl, true)) {
//it should work if you reach inside this if scope.
} else if(!(currentUrl.startWith("w", true))) {
webView.loadurl("www.$currentUrl")
} else if(!(currentUrl.startWith("h", true))) {
webView.loadurl("https://$currentUrl")
} else { ...}
}
override fun onReceivedSslError(view: WebView?, handler: SslErrorHandler?, error: SslError?) {
// you can call again loadUrl from here too if there is any error.
}
//你也应该覆盖其他覆盖错误的方法,如onReceiveError,以查看所有这些方法是如何一个接一个地被调用的,以及它们在调试断点时的行为。 } `
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);
}
}
});
这里有一个方法,它允许你注册一个Runnable,一旦一个特定的网页地址完成加载就会被执行。我们将每个可运行对象与Map中对应的URL字符串相关联,并使用WebView的getOriginalUrl()方法来选择适当的回调。
package io.github.cawfree.webviewcallback;
/**
* Created by Alex Thomas (@Cawfree), 30/03/2017.
**/
import android.net.http.SslError;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.webkit.SslErrorHandler;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import java.util.HashMap;
import java.util.Map;
/** An Activity demonstrating how to introduce a callback mechanism into Android's WebView. */
public class MainActivity extends AppCompatActivity {
/* Member Variables. */
private WebView mWebView;
private Map<String, Runnable> mCallbackMap;
/** Create the Activity. */
@Override protected final void onCreate(final Bundle pSavedInstanceState) {
// Initialize the parent definition.
super.onCreate(pSavedInstanceState);
// Set the Content View.
this.setContentView(R.layout.activity_main);
// Fetch the WebView.
this.mWebView = (WebView)this.findViewById(R.id.webView);
this.mCallbackMap = new HashMap<>();
// Define the custom WebClient. (Here I'm just suppressing security errors, since older Android devices struggle with TLS.)
this.getWebView().setWebViewClient(new WebViewClient() {
/** Handle when a request has been launched. */
@Override public final void onPageFinished(final WebView pWebView, final String pUrl) {
// Determine whether we're allowed to process the Runnable; if the page hadn't been redirected, or if we've finished redirection.
if(pUrl.equals(pWebView.getOriginalUrl())) {
// Fetch the Runnable for the OriginalUrl.
final Runnable lRunnable = getCallbackMap().get(pWebView.getOriginalUrl());
// Is it valid?
if(lRunnable != null) { lRunnable.run(); }
}
// Handle as usual.
super.onPageFinished(pWebView, pUrl);
}
/** Ensure we handle SSL state properly. */
@Override public final void onReceivedSslError(final WebView pWebView, final SslErrorHandler pSslErrorHandler, final SslError pSslError) { pSslErrorHandler.proceed(); }
});
// Assert that we wish to visit Zonal's website.
this.getWebView().loadUrl("http://www.zonal.co.uk/");
// Align a Callback for Zonal; this will be serviced once the page has loaded.
this.getCallbackMap().put("http://www.zonal.co.uk/", new Runnable() { @Override public void run() { /* Do something. */ } });
}
/* Getters. */
public final WebView getWebView() {
return this.mWebView;
}
private final Map<String, Runnable> getCallbackMap() {
return this.mCallbackMap;
}
}
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>