在Android中显示网络错误 [英] Show Network Error in android
本文介绍了在Android中显示网络错误的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我已经创建了应用的新与web视图。如果我有做任何动作和网是断开的，我想显示一个警告。我曾尝试以下，
I have created appliction with webview. if i have do any action and the net is disconnected i want to display one alert. I have tried the following,
添加了这个在onCreate方法。
added this in oncreate method.
public class AndroidNetTestActivity extends Activity {
public static WebView webview;
private Handler mHandler = new Handler();
private boolean isConnected = true;
final String offlineMessageHtml = "Net is disconnected";
final String timeoutMessageHtml = "Connection timed out";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
webview=(WebView)findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("file:///android_asset/www/index.htm");
webview.addJavascriptInterface(new MyJavaScriptInterface(), "Android");
isConnected=isNetworkAvailable();
webview.setNetworkAvailable(isConnected);
webview.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
isConnected=isNetworkAvailable();
if (isConnected) {
// return false to let the WebView handle the URL
return false;
} else {
// show the proper "not connected" message
view.loadData(offlineMessageHtml, "text/html", "utf-8");
// return true if the host application wants to leave the current
// WebView and handle the url itself
return true;
}
}
@Override
public void onReceivedError (WebView view, int errorCode,
String description, String failingUrl) {
if (errorCode == ERROR_TIMEOUT) {
view.stopLoading(); // may not be needed
view.loadData(timeoutMessageHtml, "text/html", "utf-8");
}
}
});
webview.setWebChromeClient(new WebChromeClient());
}
final class MyJavaScriptInterface
{
public void ProcessJavaScript(final String scriptname, final String args)
{
mHandler.post(new Runnable()
{
public void run()
{
//ToDo
}
});
}
}
public boolean isNetworkAvailable() {
Context context = getApplicationContext();
ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity == null) {
//boitealerte(this.getString(R.string.alert),"getSystemService rend null");
} else {
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null) {
for (int i = 0; i < info.length; i++) {
if (info[i].getState() == NetworkInfo.State.CONNECTED) {
return true;
}
}
}
}
return false;
}
}
如果我点击登录按钮，它应该显示错误信息，如果网是不可用的。
if i clicking on the log in button, it should show an error message if net is not available.
但它不能正常工作。请检查我的code和告诉我，我做错了什么
but it is not working. please check my code and tell me what i did wrong
推荐答案
确定...我更新了code。只要看看
ok... i updated your code. just have a look
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.os.Handler;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class AndroidNetTestActivity extends Activity {
public static WebView webview;
private Handler mHandler = new Handler();
private boolean isConnected = true;
final String offlineMessageHtml = "Net is disconnected";
final String timeoutMessageHtml = "Connection timed out";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.full_screen_image_layout);
webview=(WebView)findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("http://www.google.com");
webview.addJavascriptInterface(new MyJavaScriptInterface(), "Android");
isConnected=isNetworkAvailable();
webview.setNetworkAvailable(isConnected);
webview.setWebViewClient(new WebViewClient() {
/* (non-Javadoc)
* @see android.webkit.WebViewClient#onPageStarted(android.webkit.WebView, java.lang.String, android.graphics.Bitmap)
*/
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
System.out.println("page loading started");
// TODO Auto-generated method stub
if(!isNetworkAvailable2())
{
showInfoMessageDialog("network not available");
System.out.println("network not available");
return;
}
else System.out.println("network available");
super.onPageStarted(view, url, favicon);
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
isConnected=isNetworkAvailable2();
if (isConnected) {
// return false to let the WebView handle the URL
return false;
} else {
// show the proper "not connected" message
// view.loadData(offlineMessageHtml, "text/html", "utf-8");
// return true if the host application wants to leave the current
// WebView and handle the url itself
return true;
}
}
@Override
public void onReceivedError (WebView view, int errorCode,
String description, String failingUrl) {
if (errorCode == ERROR_TIMEOUT) {
view.stopLoading(); // may not be needed
// view.loadData(timeoutMessageHtml, "text/html", "utf-8");
}
}
});
//webview.setWebChromeClient(new WebChromeClient());
}
final class MyJavaScriptInterface
{
public void ProcessJavaScript(final String scriptname, final String args)
{
mHandler.post(new Runnable()
{
public void run()
{
//ToDo
}
});
}
}
private void showInfoMessageDialog(String meaasge)
{
AlertDialog alertDialog = new AlertDialog.Builder(
AndroidNetTestActivity.this).create();
alertDialog.setTitle("Connectivity");
alertDialog.setMessage(meaasge);
alertDialog.setButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
dialog.cancel();
}
});
//alertDialog.setIcon(R.drawable.error);
alertDialog.show();
}
private boolean isNetworkAvailable2()
{
System.out.println("isNetworkAvailable2 called");
NetworkInfo info = (NetworkInfo) ((ConnectivityManager) getApplicationContext()
.getSystemService(Context.CONNECTIVITY_SERVICE))
.getActiveNetworkInfo();
if (info == null || !info.isAvailable() || !info.isConnected())
return false;
else return true;
}
public boolean isNetworkAvailable() {
Context context = getApplicationContext();
ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity == null) {
//boitealerte(this.getString(R.string.alert),"getSystemService rend null");
} else {
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null) {
for (int i = 0; i < info.length; i++) {
if (info[i].getState() == NetworkInfo.State.CONNECTED) {
return true;
}
}
}
}
return false;
}
}
这篇关于在Android中显示网络错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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