我在我的应用程序中使用 WebView ，并希望确保当互联网不可用时弹出消息显示没有互联网连接，并且还在后台显示一个 html 页面，说明需要互联网连接。我添加了一些用于检查互联网连接的代码，但它无法正常工作/显示复选标记错误(根据在线研究添加的代码)。任何线索如何解决同样的问题？下面是代码:
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
// getWindow().requestFeature(Window.FEATURE_PROGRESS);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main);
progress = (ProgressBar) findViewById(R.id.ProgressBar);
progress.setVisibility(View.VISIBLE);
webview = (WebView)findViewById(R.id.webview);
if(CheckNetwork.isInternetAvailable(MainActivity.this))
{
webview.setInitialScale(1);
WebSettings webSettings = webview.getSettings();
webSettings.setJavaScriptEnabled(true);
webview.getSettings().setJavaScriptEnabled(true);
webview.getSettings().setLoadWithOverviewMode(true);
webview.getSettings().setUseWideViewPort(true);
// webview.setWebViewClient(new MyCustomWebViewClient());
if (Build.VERSION.SDK_INT >= 11){
webview.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
webview.setScrollBarStyle(View.SCROLLBARS_OUTSIDE_OVERLAY);
webview.setScrollbarFadingEnabled(false);
webview.getSettings().setRenderPriority(RenderPriority.HIGH);
webview.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
// webview.getSettings().setBlockNetworkLoads(true);
webview.getSettings().setBuiltInZoomControls(true);
webview.loadUrl("http://googi.com/money/");
webview.getSettings().setDomStorageEnabled(true);
webview.getSettings().setDatabaseEnabled(true);
webview.getSettings().setAppCacheEnabled(true);
//http://www.inpixelitrust.fr/demos/restaurant_picker/
//file:///android_asset/index.html
webview.getSettings().setSupportZoom(false);
}else{
Toast toast = Toast.makeText(MainActivity.this, "No Internet Connection", Toast.LENGTH_LONG);
toast.show();
}
/* webview.setWebChromeClient(new WebChromeClient()
{
public void onProgressChanged(WebView view, int progress)
{
// update the progressBar
MainActivity.this.setProgress(progress * 100);
}
});*/
if (!isTaskRoot()) {
final Intent intent = getIntent();
final String intentAction = intent.getAction();
if (intent.hasCategory(Intent.CATEGORY_LAUNCHER) && intentAction != null && intentAction.equals(Intent.ACTION_MAIN)) {
finish();
return;
}
}
setFullscreen();
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(event.getAction() == KeyEvent.ACTION_DOWN){
switch(keyCode)
{
case KeyEvent.KEYCODE_BACK:
if(webview.canGoBack() == true){
webview.goBack();
}else{
finish();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
super.onCreateOptionsMenu(menu);
menu.add(0, MENU_FULLSCREEN_ON, 0, R.string.menu_fullscreen_on);
menu.add(0, MENU_FULLSCREEN_OFF, 0, R.string.menu_fullscreen_off);
return true;
}
/**
* THIS IS FUNCTION FOR CHECKING INTERNET CONNECTION
* @return TRUE IF INTERNET IS PRESENT ELSE RETURN FALSE
*/
public boolean checkInternetConnection() {
ConnectivityManager cm = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo().isAvailable() && cm.getActiveNetworkInfo().isConnected()) {
return true;
} else {
return false;
}
}
@Override
public boolean onPrepareOptionsMenu(Menu menu)
{
super.onPrepareOptionsMenu(menu);
menu.findItem(MENU_FULLSCREEN_ON).setVisible(!fullscreen);
menu.findItem(MENU_FULLSCREEN_OFF).setVisible(fullscreen);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId()) {
case MENU_FULLSCREEN_ON:
fullscreen = true;
setFullscreen();
return true;
case MENU_FULLSCREEN_OFF:
fullscreen = false;
setFullscreen();
return true;
}
return false;
}
private void setFullscreen()
{
if (fullscreen) {
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
getWindow().clearFlags(
WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
} else {
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
getWindow().addFlags(
WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
}
}
/*
@Override
protected void onNewIntent(Intent intent) {
setFullscreen();
}*/
public class CheckNetwork {
final String TAG = CheckNetwork.class.getSimpleName();
public boolean isInternetAvailable(Context context)
{
NetworkInfo info = (NetworkInfo) ((ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
if (info == null)
{
Log.d(TAG,"no internet connection");
return false;
}
else
{
if(info.isConnected())
{
Log.d(TAG," internet connection available...");
return true;
}
else
{
Log.d(TAG," internet connection");
return true;
}
}
}
}
private class MyCustomWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
public void onPageStarted(WebView view, String url, Bitmap favicon) {
progress.setVisibility(View.VISIBLE);
}
public void onPageFinished(WebView view, String url) {
progress.setVisibility(View.GONE);
synchronized (SPLASH_LOCK) {
SPLASH_LOCK.notifyAll();
}
}
}
最佳答案
你可以有下面的代码。
public class CheckNetwork {
private static final String TAG = CheckNetwork.class.getSimpleName();
public static boolean isInternetAvailable(Context context)
{
NetworkInfo info = (NetworkInfo) ((ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
if (info == null)
{
Log.d(TAG,"no internet connection");
return false;
}
else
{
if(info.isConnected())
{
Log.d(TAG," internet connection available...");
return true;
}
else
{
Log.d(TAG," internet connection");
return true;
}
}
}
}
然后在Activity中你可以使用
if(CheckNetwork.isInternetAvailable(MainActivity.this))
{
// do something
}
注意:这会检查网络连接。您可能已连接到 wifi，但可能没有可用的互联网连接。
关于android - 当 WebView 无法使用互联网时，如何显示无互联网连接弹出窗口和 html 页面？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22044856/