目前我有一个WebView onPageFinished，它包含检索值的JavaScript代码。出于某种原因，JavaScript代码总是在onCreate完成后完成检索。因此，使任何可靠的检索值的代码返回null错误。让我无法使用检索数据。我对这个问题感到沮丧。我一直在寻找高低解决方案，但无济于事。
这是我的班级WebViewActivity
public class WebViewActivity extends Activity{
String[] paraText;
WebView webview;
FloatingActionButton floatingActionButton;
TextToSpeech textToSpeech;
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@SuppressLint("JavascriptInterface")
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_webview);
webview = (WebView) findViewById(R.id.webView);
floatingActionButton = (FloatingActionButton) findViewById(R.id.button_voice);
textToSpeech = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() {
@Override
public void onInit(int status) {
if(status != TextToSpeech.ERROR) {
textToSpeech.setLanguage(Locale.UK);
}
}
});
//Retrieve value from CustomAdapter
Intent intent = getIntent();
final String address = intent.getStringExtra("URL");
webViewLoadURL(address);
}
//An instance of this class will be registered as a JavaScript interface
@JavascriptInterface
@SuppressWarnings("unused")
public void onData(String[] value){
this.paraText = value;
Log.d("Output Test: Value :",value[0]);
Log.d("Output Test: P.Text :",paraText[0]);
}
public void webViewLoadURL(String address){
webview.getSettings().setJavaScriptEnabled(true);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
webview.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
webview.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
webview.getSettings().setDomStorageEnabled(true);
webview.addJavascriptInterface(this,"myjava");
webview.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
Log.d("Output Test:"," shouldOverrideUrlLoading");
return super.shouldOverrideUrlLoading(view, request);
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
Log.d("Output Test:"," onPageStarted");
}
@Override
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:"
+ "var paraTexts = [];"
+ "var count = document.getElementsByTagName('p');"
+ "var loop;"
+ "for(loop = 0; loop < count.length; loop++){"
+ "paraTexts.push(document.getElementsByTagName('p')[loop].innerHTML);"
+"}"
+ "myjava.onData(paraTexts);");
view.loadUrl("javascript:console.log('ParaText Disply' + paraTexts.toString());");
Log.d("Output Test:"," onPageFinished");
}
});
webview.loadUrl(address);
testOutput();
}
public void testOutput(){
Log.d("Output Test:"," Print");
}
}