java.lang.RuntimeException: Unable to instantiate activit - java

I'm trying to write an Android app that logs when you click a button it will put text into the console, however I am getting an error when I complie it and run it on my Galaxy S7 edge running 7.0 API version 24.
I've read that I need to add something into the manifest file however I am not sure what I need to add.
FATAL EXCEPTION: main
Process: me.adamstephenson.test.test1, PID: 16405
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{me.adamstephenson.test.test1/me.adamstephenson.test.test1.MainActivity}: java.lang.ClassCastException: me.adamstephenson.test.test1.MainActivity cannot be cast to android.app.Activity
package me.adamstephenson.test.test1;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
public class MainActivity {
public class MyActivity extends Activity {
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_main);
final Button button = (Button) findViewById(R.id.RequestKey);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.d("RequestKey", "Clicked");
}
});
}
}
}
Source
Here is the layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="me.adamstephenson.test.test1.MainActivity">
<Button
android:id="#+id/RequestKey"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
tools:layout_editor_absoluteX="196dp"
tools:layout_editor_absoluteY="129dp" />
</android.support.constraint.ConstraintLayout>
Finally here is the manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="me.adamstephenson.test.test1">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<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>

You are referring to the wrong class in your manifest. MyActivity is the Activity, not MainActivity. Change your manifest to the following :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="me.adamstephenson.test.test1">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity$MyActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
And
You should make your inner activity static as well :
public class MainActivity {
public static class MyActivity extends Activity {
...
}
}

Because your activity class is created as a inner class and static class. I don't have any idea why did you choose this way while you can use it this proper way:
public class MyActivity extends Activity {
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_main);
final Button button = (Button) findViewById(R.id.RequestKey);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.d("RequestKey", "Clicked");
}
});
}
.
.
.
// other methods or inner class can exist here
}

Related

Android studio - some of the interpolator animations not working

I am trying to apply animations to my project, when I set the interpolator to:
alpha.xml:
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/bounce_interpolator">
<alpha android:fromAlpha="0"
android:toAlpha="1"
android:duration="4000"
/>
</set>
SplashActivity.java:
package com.example.animationtesting;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.TextView;
public class SplashActivity extends AppCompatActivity {
ImageView imageView;
TextView textView;
Animation alpha;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
imageView = findViewById(R.id.imageView);
textView = findViewById(R.id.textView);
alpha = AnimationUtils.loadAnimation(this,R.anim.alpha);
imageView.setAnimation(alpha);
textView.setAnimation(alpha);
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
Intent intent = new Intent(SplashActivity.this,MainActivity.class);
startActivity(intent);
finish();
}
},4000);
}
}
Android Manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<application
android:allowBackup="true"
android:dataExtractionRules="#xml/data_extraction_rules"
android:fullBackupContent="#xml/backup_rules"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.AnimationTesting"
tools:targetApi="31">
<activity
android:name=".SplashActivity"
android:exported="true"
android:theme="#style/Theme.AppCompat.Light.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<meta-data
android:name="android.app.lib_name"
android:value="" />
</activity>
<activity
android:name=".MainActivity"
android:exported="true">
<meta-data
android:name="android.app.lib_name"
android:value="" />
</activity>
</application>
</manifest>
The code is working fine when I set the interpolator as bounce_interpolator, accelerate_interpolator, anticipate_overshoot_interpolator but when I set the interpolator to other options like fade_in, fade_out,slide_out_right my app crashes. I don't get why this is happening.
First I thought your app crashed because you try to put the animation on two different xml-objects, but then I replicated the entire thing using this guide and for me, everything is working. (Although I did it using Kotlin).
I'm sorry, the only solution I could provide was this URL to the guide, but if you have any more questions, feel free to ask!

Errors while adding splash screen in android

I am new to android development, and I'm trying to add a splash screen in my app.
I found this tutorial:
I have added the files as mentioned in the tutorial but it doesn't seems to work, there is an error in my Splashscreen.java file
It gives me the error cannot resolve symbol androidmkab
Thanks for helping in advance.
Splashscreen.java
package com.myapplication;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.widget.ImageView;
import com.androidmkab.randomsplash.MainActivity;
import java.util.Random;
public class Splashscreen extends Activity {
Thread splashTread;
ImageView imageView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splashscreen);
imageView = (ImageView)findViewById(R.id.imageView2);
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
int[] ids = new int[]{R.drawable.s_img,R.drawable.s_image_black, R.drawable.s_image_black2};
Random randomGenerator = new Random();
int r= randomGenerator.nextInt(ids.length);
this.imageView.setImageDrawable(getResources().getDrawable(ids[r]));
splashTread = new Thread() {
#Override
public void run() {
try {
int waited = 0;
// Splash screen pause time
while (waited < 3500) {
sleep(100);
waited += 100;
}
Intent intent = new Intent(Splashscreen.this,
MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
startActivity(intent);
Splashscreen.this.finish();
} catch (InterruptedException e) {
// do nothing
} finally {
Splashscreen.this.finish();
}
}
};
splashTread.start();
}
}
activity_splash.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ffffff"
android:layout_gravity="center"
android:id="#+id/lin_lay"
android:gravity="center"
android:orientation="vertical" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/splash"
android:background="#drawable/logo" />
</LinearLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.myapplication">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".Splashscreen"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
import com.androidmkab.randomsplash.MainActivity; remove this line from the top. Its not your package... instead make it import com.myapplication.MainActivity
the problem seems to be that you are trying to call a package which does not exist in your project. androidmkab.randomsplash.MainActivity should be replaced with your project package. such as com.myApplication.MainActivity
Delete the line com.androidmkab.randomsplash.MainActivity; and write com.myapplication.MainActivity;

How can remove the titlebar and remain the browser in fullscreen

I'm trying to create my first app, the browser for android with this code already done, but needed to adapt to my necessity. I still do not know java, and the examples I find I can not make it work.
I need help and reading.
How can remove the titlebar and remain the browser in fullscreen?
for later viewing and interacting with my application in jquery mobile
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class AndroidMobileAppSampleActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
WebView mainWebView = (WebView) findViewById(R.id.mainWebView);
WebSettings webSettings = mainWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
mainWebView.setWebViewClient(new MyCustomWebViewClient());
mainWebView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
mainWebView.loadUrl("http://www.");
}
private class MyCustomWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
}
}
//AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="tscolari.mobile_sample"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="android.permission.INTERNET"/>
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".AndroidMobileAppSampleActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
1 - in your layout, set the WebView to match_parent in both layout_width and layout_height
2 - in your code, add these lines:
super.onCreate(savedInstanceState);
// Hiding Title bar of this activity screen
getWindow().requestFeature(Window.FEATURE_NO_TITLE);
// Making this activity full screen
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main);
in place of the existing
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
If your IDE is NOT SET to add the missing imports, just add the following line to your imports:
import android.view.Window;
import android.view.WindowManager;
update your manifeist like this :
only mentioning one thing:
android:theme="#android:style/Theme.NoTitleBar"
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="tscolari.mobile_sample"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="android.permission.INTERNET"/>
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".AndroidMobileAppSampleActivity"
android:label="#string/app_name"
android:theme="#android:style/Theme.NoTitleBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

Unfortunately, app has stopped

Unfortunately, app has stopped. The purpose of the app is to display a web page when it is launched. I have researched this problem, and tried changing code in the manifest file. I have been unsuccessful at eliminating this message.
MainActivity.java
package com.example.testb1;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.content.Intent;
import android.net.Uri;
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState)
{
Intent getmobilepages = new Intent(Intent.ACTION_VIEW);
Uri uri = Uri.parse("http://www.mcohio.org/government/auditor/mobile_app/home.cfm");
getmobilepages.setData(uri);
startActivity(getmobilepages);
}
}
testb1 Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.testb1"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.testb1.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
<action android:name="android.intent.action.getmobilepages" />
</intent-filter>
</activity>
</application>
</manifest>
Edit: I tried running your code and was completely wrong. You are just missing the line:
super.onCreate(savedInstanceState);
At the start of your oncreate method. Add that in and it should compile just fine.
Make sure to post your logcat in the future, the error is identified clearly there.
You have not called super you will get SuperNotCalled Exception. You need to set you layout. Better to start another activity on button click.
Add internet permission in manifest
<uses-permission android:name="android.permission.INTERNET"/>
MainActivty
public class MainActivity extends Activity {
Button b;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// call super
setContentView(R.layout.activity_main);
// set your layout
b = (Button) findViewById(R.id.button1);
//get button id
b.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
// do something
Intent getmobilepages = new Intent(Intent.ACTION_VIEW);
Uri uri = Uri.parse("http://www.mcohio.org/government/auditor/mobile_app/home.cfm");
getmobilepages.setData(uri);
startActivity(getmobilepages);
}
});
}
}

Android unexcpected error

I am a beginner of Android and i need a bit hints and help. I am using following code
public class WifiHotSpotActivity extends Activity {
private Button adnew = null;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
adnew = (Button) findViewById(R.id.addNewBtn);
adnew.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
Intent myIntent = new Intent(v.getContext(), addNew.class);
startActivityForResult(myIntent, 0);
}
});
}
The error i am receiving is
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.kahaf.wifiHotSpot/com.kahaf.wifiHotSpot.addNew}; have you declared this activity in your AndroidManifest.xml?
if anyone can tell me what is the problem.
You should define your activity in the manifest file. Here's an example how your manifest should look after the addition of that activity:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.foo.test"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
>
<activity
android:label="#string/app_name"
android:name=".FooActivity"
android:configChanges="keyboardHidden">"
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".YourActivityNameHere"
android:label="#string/app_name"
>
</activity>
<activity
android:name=".AnotherActivity"
android:label="#string/app_name"
>
</activity>
</application>
</manifest>
put this to AndroidManifest.xml
<activity android:name=".WifiHotSpotActivity"/>
It looks like you've not defined the Activity Element in the manifest xml for WifiHotSpotActivity. Without this you will be unable to launch this activity.
go to manifest the application tag.. add activity "addNew" which you are calling in button click..

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