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
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。 ｝ ｀
其他回答
@ian这不是百分之百准确的。如果你有几个iframe在一个页面，你将有多个onPageFinished(和onpagstarted)。如果你有几个重定向，它也可能失败。这种方法解决了(几乎)所有问题:
boolean loadingFinished = true;
boolean redirect = false;
mWebView.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String urlNewString) {
if (!loadingFinished) {
redirect = true;
}
loadingFinished = false;
webView.loadUrl(urlNewString);
return true;
}
@Override
public void onPageStarted(WebView view, String url) {
loadingFinished = false;
//SHOW LOADING IF IT ISNT ALREADY VISIBLE
}
@Override
public void onPageFinished(WebView view, String url) {
if (!redirect) {
loadingFinished = true;
//HIDE LOADING IT HAS FINISHED
} else {
redirect = false;
}
}
});
更新:
根据文档: 当嵌入帧的内容发生变化时，onpagstarted将不会被调用，即单击目标为iframe的链接。
我在Twitter上发现了一个类似的特定情况，其中只调用了pageFinished，逻辑有点混乱。为了解决这个问题，我添加了一个计划任务，在X秒后删除加载。这在所有其他情况下都不需要。
更新2:
现在使用当前的Android WebView实现:
boolean loadingFinished = true;
boolean redirect = false;
mWebView.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(
WebView view, WebResourceRequest request) {
if (!loadingFinished) {
redirect = true;
}
loadingFinished = false;
webView.loadUrl(request.getUrl().toString());
return true;
}
@Override
public void onPageStarted(
WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
loadingFinished = false;
//SHOW LOADING IF IT ISNT ALREADY VISIBLE
}
@Override
public void onPageFinished(WebView view, String url) {
if (!redirect) {
loadingFinished = true;
//HIDE LOADING IT HAS FINISHED
} else {
redirect = false;
}
}
});
我把NeTeInStEiN的代码简化成这样:
mWebView.setWebViewClient(new WebViewClient() {
private int webViewPreviousState;
private final int PAGE_STARTED = 0x1;
private final int PAGE_REDIRECTED = 0x2;
@Override
public boolean shouldOverrideUrlLoading(WebView view, String urlNewString) {
webViewPreviousState = PAGE_REDIRECTED;
mWebView.loadUrl(urlNewString);
return true;
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
webViewPreviousState = PAGE_STARTED;
if (dialog == null || !dialog.isShowing())
dialog = ProgressDialog.show(WebViewActivity.this, "", getString(R.string.loadingMessege), true, true,
new OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
// do something
}
});
}
@Override
public void onPageFinished(WebView view, String url) {
if (webViewPreviousState == PAGE_STARTED) {
dialog.dismiss();
dialog = null;
}
}
});
这很容易理解，OnPageFinished如果之前的回调是onpagstarted，所以页面是完全加载的。
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
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。 ｝ ｀
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;
}
}
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