Hello I'm trying to get my button that I have in my main XML file to only appear when there's no internet So that's why I can get the button to only appear when there's no internet and so it's not shown anywhere else unless there's internet can someone please help me?
Blow i have listed the code for both the main XML and the main Java file
xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
tools:context=".MainActivity">
<WebView
android:layout_width="10dp"
android:layout_height="10dp"
tools:ignore="MissingConstraints"
tools:layout_editor_absoluteX="200dp"
tools:layout_editor_absoluteY="361dp"/>
<Button
android:id="@ id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
tools:layout_editor_absoluteX="202dp"
tools:layout_editor_absoluteY="399dp" />
</androidx.constraintlayout.widget.ConstraintLayout>\
java
public class MainActivity extends AppCompatActivity {
@SuppressLint("SetJavaScriptEnabled")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WebView webView = new WebView(this);
WebSettings webSettings = webView.getSettings();
webSettings.setBuiltInZoomControls(true);
webSettings.setJavaScriptEnabled(true);
setContentView(webView);
webView.getSettings().setLoadWithOverviewMode(true);
webView.getSettings().setUseWideViewPort(true);
webView.getSettings().setSupportZoom(true);
webView.getSettings().setBuiltInZoomControls(true);
webView.getSettings().setDisplayZoomControls(false);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.setScrollbarFadingEnabled(false);
if(isNetworkAvailable(this)){
webView.loadUrl("https://racks.tk");
} else {
Toast.makeText(this,"No internet. Please check internet connection and try again", Toast.LENGTH_LONG).show();
}
}
public static boolean isNetworkAvailable(Context context) {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivityManager != null) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
NetworkCapabilities capabilities = connectivityManager.getNetworkCapabilities(connectivityManager.getActiveNetwork());
return capabilities != null && (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) || capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) || capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET));
} else {
NetworkInfo activeNetwork = connectivityManager.getActiveNetworkInfo();
return activeNetwork != null && activeNetwork.isConnected();
}
}
return false;
}
CodePudding user response：
You are creating a web view programmatically and then trying to access a button from an XML file and you have not linked the XML file in the Java file, so it crashes. Update your code with this code completely
XML file - 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"
tools:context=".MainActivity">
<ProgressBar
android:id="@ id/my_progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:indeterminate="true"/>
<WebView
android:id="@ id/my_webview"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<Button
android:id="@ id/reload_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="Retry" />
</RelativeLayout>
java file - MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkCapabilities;
import android.net.NetworkInfo;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
@SuppressLint("SetJavaScriptEnabled")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WebView webView = findViewById(R.id.my_webview);
Button reloadBtn = findViewById(R.id.reload_btn);
ProgressBar progress = findViewById(R.id.my_progress);
WebSettings webSettings = webView.getSettings();
webSettings.setBuiltInZoomControls(true);
webSettings.setJavaScriptEnabled(true);
webSettings.setLoadWithOverviewMode(true);
webSettings.setUseWideViewPort(true);
webSettings.setSupportZoom(true);
webSettings.setBuiltInZoomControls(true);
webSettings.setDisplayZoomControls(false);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.setScrollbarFadingEnabled(false);
webView.setWebViewClient(new WebViewClient(){
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
webView.setVisibility(View.GONE);
}
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
progress.setVisibility(View.GONE);
webView.setVisibility(View.VISIBLE);
}
});
if (isNetworkAvailable(this)) {
webView.loadUrl("https://racks.tk");
reloadBtn.setVisibility(View.GONE);
} else {
Toast.makeText(this, "No internet. Please check internet connection and try again", Toast.LENGTH_LONG).show();
reloadBtn.setVisibility(View.VISIBLE);
}
reloadBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (isNetworkAvailable(MainActivity.this)){
reloadBtn.setVisibility(View.GONE);
webView.loadUrl("https://racks.tk");
}else {
reloadBtn.setVisibility(View.VISIBLE);
Toast.makeText(MainActivity.this, "No internet. Please check internet connection and try again", Toast.LENGTH_LONG).show();
}
}
});
}
public static boolean isNetworkAvailable(Context context) {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivityManager != null) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
NetworkCapabilities capabilities = connectivityManager.getNetworkCapabilities(connectivityManager.getActiveNetwork());
return capabilities != null && (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) || capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) || capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET));
} else {
NetworkInfo activeNetwork = connectivityManager.getActiveNetworkInfo();
return activeNetwork != null && activeNetwork.isConnected();
}
}
return false;
}
}
CodePudding user response：
You are missing the @Override :
Button button = findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override //Right here
public void onClick(View v) {
webView.loadUrl( "javascript:window.location.reload( true )" );
}
});
CodePudding user response：
Button button= findViewById(R.id.button);
if(isNetworkAvailable(this)){
webView.loadUrl("myurl.com");
button.setVisibility(View.VISIBLE)
} else {
button.setVisibility(View.GONE)
Toast.makeText(this,"check internet connection and try again", Toast.LENGTH_LONG).show();
}