私のアプリケーションには、インターネットからURLをロードするWebView
があります。現在、ネットワークの速度が遅いために、ページの読み込みに時間がかかり、ユーザーには空白の画面しか表示されません。
ProgressBar
が読み込まれている間にWebView
を表示し、ProgessBar
が完全に読み込まれたときにWebView
を非表示にします。
ProgressBar
とAsyncTask
sの使用方法は知っていますが、ここに問題があります。
これは、WebView
をロードするために使用するコードです。
mWebView = (WebView) findViewById(R.id.webview);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setWebViewClient(new HelloWebViewClient());
mWebView.loadUrl(web_URL);
そして、これは私のカスタムWebViewClient
クラス
private class HelloWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
}
今、ProgressBar
sを使用してAsyncTask
を表示を試みた場合、doInBackGround()
にURLをロードするコードを提供する必要があると思いますAsyncTask
の関数で、onProgressUpdate()
関数を使用して進行状況を表示します。
しかし、doInBackground()内でdoInBackground()が非UIスレッドで実行され、mWebView.loadUrl(web_URL)
その中。
助言がありますか?明らかな何かが欠けていますか?案内してください。
ソースコードを確認してください。あなたを助け、あなたの問題を解決します...
public class AppWebViewClients extends WebViewClient {
private ProgressBar progressBar;
public AppWebViewClients(ProgressBar progressBar) {
this.progressBar=progressBar;
progressBar.setVisibility(View.VISIBLE);
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// TODO Auto-generated method stub
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
// TODO Auto-generated method stub
super.onPageFinished(view, url);
progressBar.setVisibility(View.GONE);
}
}
役立つと思います。
ありがとう。
WebViewが読み込まれている間にprogressBarを表示し、webViewが完全に読み込まれたときにprogessBarを非表示にします。
次のスニペットが役立ちます。
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
Android:orientation="vertical"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
>
<WebView Android:id="@+id/webview"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
Android:layout_weight="1" />
</LinearLayout>
Main.class
public class Main extends Activity {
private WebView webview;
private static final String TAG = "Main";
private ProgressDialog progressBar;
/** Called when the activity is first created. */@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
this.webview = (WebView) findViewById(R.id.webview);
WebSettings settings = webview.getSettings();
settings.setJavaScriptEnabled(true);
webview.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
final AlertDialog alertDialog = new AlertDialog.Builder(this).create();
progressBar = ProgressDialog.show(Main.this, "Showing ProgressDialog", "Loading...");
webview.setWebViewClient(new WebViewClient() {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
Log.i(TAG, "Processing webview url click...");
view.loadUrl(url);
return true;
}
public void onPageFinished(WebView view, String url) {
Log.i(TAG, "Finished loading URL: " + url);
if (progressBar.isShowing()) {
progressBar.dismiss();
}
}
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Log.e(TAG, "Error: " + description);
Toast.makeText(Main.this, "Oh no! " + description, Toast.LENGTH_SHORT).show();
alertDialog.setTitle("Error");
alertDialog.setMessage(description);
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
return;
}
});
alertDialog.show();
}
});
webview.loadUrl("http://www.google.com");
}
}
このメソッドでURLを渡します
private void startWebView(String url) {
WebSettings settings = webView.getSettings();
settings.setJavaScriptEnabled(true);
webView.setScrollBarStyle(View.SCROLLBARS_OUTSIDE_OVERLAY);
webView.getSettings().setBuiltInZoomControls(true);
webView.getSettings().setUseWideViewPort(true);
webView.getSettings().setLoadWithOverviewMode(true);
progressDialog = new ProgressDialog(ContestActivity.this);
progressDialog.setMessage("Loading...");
progressDialog.show();
webView.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
}
@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Toast.makeText(ContestActivity.this, "Error:" + description, Toast.LENGTH_SHORT).show();
}
});
webView.loadUrl(url);
}
ユーザーが(最初の読み込みだけでなく)ページを読み込むたびにプログレスバーを表示したい場合、これを使用できます:
MainActivity.Java
public class MainActivity extends Activity
{
private WebView webView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webView = (WebView) findViewById(R.id.webView);
final ProgressDialog progressBar = new ProgressDialog(MainActivity.this);
progressBar.setMessage("Please wait...");
webView.loadUrl("https://example.org/");
webView.setWebViewClient(new WebViewClient() {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
if (!progressBar.isShowing()) {
progressBar.show();
}
}
public void onPageFinished(WebView view, String url) {
if (progressBar.isShowing()) {
progressBar.dismiss();
}
}
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
if (progressBar.isShowing()) {
progressBar.dismiss();
}
}
});
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<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"
Android:paddingBottom="0dp"
Android:paddingLeft="0dp"
Android:paddingRight="0dp"
Android:paddingTop="0dp"
tools:showIn="@layout/activity_main">
<WebView
Android:id="@+id/webView"
Android:layout_width="wrap_content"
Android:layout_height="wrap_content"
Android:layout_alignParentBottom="true"
Android:layout_alignParentEnd="true"
Android:layout_alignParentLeft="true"
Android:layout_alignParentRight="true"
Android:layout_alignParentStart="true"
Android:layout_alignParentTop="true" />
</RelativeLayout>
String url = "https://stackoverflow.com/questions/11241513/Android-progessbar-while-loading-webview";
setProgressBarVisibility(View.VISIBLE);
webView.setWebViewClient(new WebViewClient() {
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
setProgressBarVisibility(View.VISIBLE);
}
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
setProgressBarVisibility(View.GONE);
}
@Override
public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
super.onReceivedError(view, request, error);
setProgressBarVisibility(View.GONE);
}
});
webView.loadUrl(url);
メソッドも追加します:
private void setProgressBarVisibility(int visibility) {
// If a user returns back, a NPE may occur if WebView is still loading a page and then tries to hide a ProgressBar.
if (progressBar != null) {
progressBar.setVisibility(visibility);
}
}
@SuppressLint("SetJavaScriptEnabled")
private void init() {
webView = (WebView) findViewById(R.id.kamal);
webView.setBackgroundColor(0);
webView.getSettings().setJavaScriptEnabled(true);
progressDialog = new ProgressDialog(WebView_Ofline.this);
progressDialog.setMessage("Loading Please wait...");
progressDialog.setCancelable(false);
progressDialog.show();
webView.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
try {
progressDialog.dismiss();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
myThanh.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
final AlertDialog alertDialog = new AlertDialog.Builder(this).create();
progressBar = ProgressDialog.show(MainActivity.this,"Đang tải dữ liệu", "Vui lòng chờ...");
myThanh.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
if (progressBar.isShowing()) {
progressBar.dismiss();
}
}
});
OnPageFinished()メソッドの進捗状況を不正確にしようとしていますが、あまり良くありません。ウェブビューのレンダリングに時間がかかります。
onPageCommitVisible()を試してください。
val progressBar = ProgressDialog(context)
progressBar.setCancelable(false)
progressBar.show()
web_container.webViewClient = object : WebViewClient() {
override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {
view.loadUrl(url)
progressBar.show()
return true
}
override fun onPageCommitVisible(view: WebView?, url: String?) {
super.onPageCommitVisible(view, url)
progressBar.dismiss()
}
}
この簡単な解決策は[〜#〜] kotlin [〜#〜]で機能しました。
private fun setupWebView() {
val webViewClient: WebViewClient = object: WebViewClient() {
override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {
view?.loadUrl(request?.url.toString())
return super.shouldOverrideUrlLoading(view, request)
}
override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
showProgressDialog()
super.onPageStarted(view, url, favicon)
}
override fun onPageFinished(view: WebView?, url: String?) {
hideProgressDialog()
super.onPageFinished(view, url)
}
}
webView.webViewClient = webViewClient
webView.settings.javaScriptEnabled = true
webView.settings.defaultTextEncodingName = "utf-8"
}
WebView webView;
ProgressDialog progressDialog;
TextView text;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_web_view);
String message = getIntent().getStringExtra("key").toString();
setTitle(message);
Bundle isNetworkAvailable = getIntent().getExtras();
String value = "file:///Android_asset/n/o/i/no_connection.html";
if (isNetworkAvailable()) {
value = isNetworkAvailable.getString("keyHTML");
}
webView = (WebView) findViewById(R.id.kamal);
webView.loadUrl(value);
init();
}
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
private void init() {
webView = (WebView) findViewById(R.id.kamal);
webView.getSettings().setBuiltInZoomControls(true);
webView.setBackgroundColor(0);
webView.getSettings().setJavaScriptEnabled(true);
progressDialog = new ProgressDialog(WebView_Online.this);
progressDialog.setMessage("Loading Please wait...");
progressDialog.setCancelable(false);
progressDialog.show();
webView.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
try {
progressDialog.dismiss();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
これをコードに貼り付けて、URLを追加します
var progressDialog: ProgressDialog? = null
private fun startWebView(url: String) {
val settings = webView.getSettings()
settings.setJavaScriptEnabled(true)
webView.setScrollBarStyle(View.SCROLLBARS_OUTSIDE_OVERLAY)
webView.getSettings().setBuiltInZoomControls(true)
webView.getSettings().setUseWideViewPort(true)
webView.getSettings().setLoadWithOverviewMode(true)
progressDialog = ProgressDialog(this)
progressDialog!!.setMessage("Loading...")
progressDialog!!.show()
webView.setWebViewClient(object : WebViewClient() {
override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {
view.loadUrl(url)
return true
}
override fun onPageFinished(view: WebView, url: String) {
if (progressDialog!!.isShowing()) {
progressDialog!!.dismiss()
}
}
override fun onReceivedError(view: WebView, errorCode: Int, description: String, failingUrl: String) {
Toast.makeText(this@MainActivity, "Error:$description", Toast.LENGTH_SHORT).show()
}
})
webView.loadUrl(url)
}