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
使用setWebViewClient()并重写onPageFinished()
其他回答
我非常倾向于@NeTeInStEiN(和@polen)解决方案,但会用一个计数器来实现它,而不是多个布尔值或状态监视器(只是另一种风格,但我认为可能会共享)。它确实有一个JS的细微差别,但我觉得逻辑是更容易理解一点。
private void setupWebViewClient() {
webView.setWebViewClient(new WebViewClient() {
private int running = 0; // Could be public if you want a timer to check.
@Override
public boolean shouldOverrideUrlLoading(WebView webView, String urlNewString) {
running++;
webView.loadUrl(urlNewString);
return true;
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
running = Math.max(running, 1); // First request move it to 1.
}
@Override
public void onPageFinished(WebView view, String url) {
if(--running == 0) { // just "running--;" if you add a timer.
// TODO: finished... if you want to fire a method.
}
}
});
}
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。
对于Kotlin用户:
webView.webViewClient = object : WebViewClient() {
override fun onPageFinished(view: WebView?, url: String?) {
// do your logic
}
}
有很多方法你可以重写
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);
}
}
});
使用setWebViewClient()并重写onPageFinished()