Menu
I searched over the net, and tried most of the similar topics in stackoverflow, but couldn't solve this. That's why I'm posting a question.
I want to create a very simple android application. There is a button, and if the user clicks on that button, it should open a specific website inside that application. That's it.
I've set the settings of this example project for Android 4.1.
After writing the codes, I do Build / Make Project , and then Build / Build APK , and then install this APK in my android phone (Android 7.0).
After installing and opening the app, I press the CONNECT button, but just right then, the app disappears (goes to background); it does not open the website.
Here are my codes:
MainActivity.java
package example_company.test_2;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.view.View;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void goToGoogle (View view) {
goToUrl ( "http://www.google.com/");
}
private void goToUrl (String url) {
Uri uriUrl = Uri.parse(url);
Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl);
startActivity(launchBrowser);
}
}
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:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="example_company.test_2.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
<Button
android:text="CONNECT"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:id="@+id/button"
android:onClick="goToGoogle (MainActivity)" />
</RelativeLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="example_company.test_2">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="www.google.com" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
So, what is the problem? Am I missing something !?
EDIT1
Here is the logcat errors when I press the CONNECT button, after changing the codes according to the answer from @pleft :
10-31 13:51:25.681 12178-12178/example_company.test_2 E/AndroidRuntime: FATAL EXCEPTION: main
Process: example_company.test_2, PID: 12178
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:5646)
at android.view.View$PerformClick.run(View.java:22459)
at android.os.Handler.handleCallback(Handler.java:761)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6531)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:941)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:831)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5646)
at android.view.View$PerformClick.run(View.java:22459)
at android.os.Handler.handleCallback(Handler.java:761)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6531)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:941)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:831)
Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {example_company.test_2/example_company.test_2.WebViewActivity}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1850)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1544)
at android.app.Activity.startActivityForResult(Activity.java:4391)
at android.support.v4.app.BaseFragmentActivityJB.startActivityForResult(BaseFragmentActivityJB.java:48)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:75)
at android.app.Activity.startActivityForResult(Activity.java:4335)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:856)
at android.app.Activity.startActivity(Activity.java:4697)
at android.app.Activity.startActivity(Activity.java:4665)
at example_company.test_2.MainActivity.goToUrl(MainActivity.java:25)
at example_company.test_2.MainActivity.goToGoogle(MainActivity.java:19)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5646)
at android.view.View$PerformClick.run(View.java:22459)
at android.os.Handler.handleCallback(Handler.java:761)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6531)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:941)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:831)
639
Update your manifest to allow internet connection
<uses-permission android:name="android.permission.INTERNET"/>
Create the layout of your webview
webview.xml
<?xml version="1.0" encoding="utf-8"?>
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/webview"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
WebViewActivity classWebViewActivity
public class WebViewActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview);
Intent i = getIntent();
String url= i.getStringExtra("url");
WebView webView = findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
assert url != null;
webView.loadUrl(url);
}
}
Update your MainActivity.goToUrl code to the following:
private void goToUrl (String url) { Intent intent = new Intent(this, WebViewActivity.class); intent.putExtra("url", url); startActivity(intent); }
Change in your activity_main.xml the line:
android:onClick="goToGoogle (MainActivity)"
to
android:onClick="goToGoogle"
To resolve the error in the logcat stacktrace posted in the question, the new activity must be declared in the manifest. So just above the line
add the following:
<activity android:name=".WebViewActivity" android:theme="@android:style/Theme.NoTitleBar"/>
webView.getSettings().setJavaScriptEnabled(true); it will lead to a warning that setJavaScriptEnabled can introduce XSS vulnerabilities into your application, so review carefully! Or you can simply remove it if you don't want to use JS in your webview.UPDATE
The final working codes look like the following:
MainActivity.java
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.view.View;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void goToGoogle (View view) {
goToUrl ( "http://www.google.com/");
}
private void goToUrl (String url) {
Intent intent = new Intent(this, WebViewActivity.class);
intent.putExtra("url", url);
intent.putExtra("name", "Your Title Name");
startActivity(intent);
}
}
WebViewActivity.java
package example_company.test_2;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ImageButton;
import android.widget.TextView;
public class WebViewActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_web_view);
Intent i = getIntent();
String url= i.getStringExtra("url");
WebView webView = findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
assert url != null;
webView.loadUrl(url);
TextView textView = findViewById(R.id.name);
textView.setText(i.getStringExtra("name"));
textView.setOnClickListener(v -> finish());
ImageButton imageButton = findViewById(R.id.backbtn);
imageButton.setOnClickListener(v -> finish());
}
}
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:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="example_company.test_2.MainActivity">
<Button
android:text="CONNECT"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:id="@+id/button"
android:onClick="goToGoogle"
android:textAppearance="@style/TextAppearance.AppCompat.Display1" />
</RelativeLayout>
webview.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".WebViewActivity">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPrimaryDark"
android:theme="@style/Base.ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:popupTheme="@style/MenuStyle">
<ImageButton
android:id="@+id/backbtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/ic_arrow_back_black_24dp"
android:contentDescription="Back"
tools:ignore="HardcodedText" />
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_marginStart="10dp"
android:layout_marginLeft="10dp"
android:textColor="#fff"
android:textSize="18sp"
android:textStyle="bold" />
</androidx.appcompat.widget.Toolbar>
<WebView
android:id="@+id/webview"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/toolbar" />
</androidx.constraintlayout.widget.ConstraintLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="example_company.test_2">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".WebViewActivity" android:theme="@android:style/Theme.NoTitleBar"/>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Screenshot:
100
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