Respond to send button - android

I installed the Android SDK bundle today and I am following the "My First App" tutorial and I am stuck, it states:
Open the MainActivity class (located in the project's src/ directory) and add the corresponding method:
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
}
Where do I put this in the file? and is this the "MainActivity.java" file?
I have tried and I keep getting errors so I am obviously going wrong somewhere.
activity_main.xml:
<LinearLayout 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"
android:orientation="horizontal">
<EditText android:id="#+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:onClick="sendMessage" />
</LinearLayout>
MainActivity.java:
package com.example.myfirstapp;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
Hope I have made my problem clear, I looked on the forum for an answer but I couldn't find anything.

If you have a button in your(say activity_main.xml) xml layout and you have the below attribute for button
android:onClick="sendMessage"
and you have the below in MainActiivty.java
setContentView(R.layout.activity_main);
You should have the below in MainActivity.java
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
}
Example:
MainActivity.java
// Your imports
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); //setting the layout to activity
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
// other widgets
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="146dp"
android:onClick="sendMessage"
android:text="Button" />
</RelativeLayout>

If you are a new android developer and doing your first so start from basic like launch new activity it contain hello world or any text view, button then you will clear idea about application.
create your android application
in XML layout drag the button and text view
run your first app.
you will get your output.

Put it in MainActivity.java at the top right after
public class MainActivity extends ActionBarActivity {
After you do this, you may have to import. Do this by pressing control / shift / O (not zero)

Related

Android Studio - Button Click Crash (Simple)

I'm brand new to Android Studio and for whatever reason am experiencing really weird errors if I could please get some help.
I have very basic code that is supposed to, on button click change the text of my button from "button" to "clicked!". However everytime I press the button, the app crashes and I get "Appname has stopped" on the emulator.
What is incredibly weird is that in my activity_main.xml Design view, the onClick dropdown shows two functions of the same name (https://puu.sh/t2h5I/42ad4379d6.png)
H owever the code only works when the bottom one is selected. AND each time I run the app, it deselects the bottom one and reselects the top, only to stop working.
Here is my MainActivity:
package com.example.john.ameladay;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
public Button melButtonCode;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void buttonPress(View v){
melButtonCode = (Button) v;
((Button) v).setText("Has been clicked!");
}
}
Here is my 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="com.example.john.ameladay.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/mainText"
android:id="#+id/textView" />
<ImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/mela"
android:id="#+id/melPhoto" />
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#+id/textView"
android:layout_toEndOf="#+id/textView"
android:layout_marginLeft="32dp"
android:layout_marginStart="32dp"
android:layout_marginBottom="43dp"
android:id="#+id/button"
android:onClick="buttonPress (MainActivity)" />
Any help would be greatly appreciated!!
Simple. You should write:
android:onClick="buttonPress"
Why happened
If you wrote buttonPress (MainActivity), Android tries to find buttonPress (MainActivity) method (not MainActivity.buttonPress()), but MainActivity doesn't have buttonPress (MainActivity) method. So the error happened.
Simply replace this Tag in button
Remove this
android:onClick="buttonPress (MainActivity)"
And Paste This
android:onClick="buttonPress"
A better way to do it is, get a reference to the button in your Java code using findViewById() method and set an OnClickListener to the button.
For your current problem, use
android:onClick="buttonPress"
instead of
android:onClick="buttonPress (MainActivity)"
According to me this is the better way to set click on button
public class MainActivity extends AppCompatActivity {
public Button melButtonCode;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
melButtonCode = (Button).findViewById(R.id.button);//find button by Id
melButtonCode.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
melButtonCode.setText("Has been clicked!");
}
});
}
}
For your problem
replace it
android:onClick="buttonPress (MainActivity)"
With
android:onClick="buttonPress"
Make the method public - protected works when you are in instantrun mode, but not when not. No idea why!

App chrashes while changing view

I want to create a very simple app. The app should consists of 2 views. In both views are one button. By clicking the button the view should change.
Here is my folder structure
I have two activitys and two activity_layouts. As you can see OverviewActivity isn't inside the activity folder. When I place it into the folder I get this structur:
Why is the activity folder away? Can you give me a little explanation?
Ok, but in this question I use the first folder structur.
activity_login.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"
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="company.useradministration.activity.LoginActivity">
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:onClick="btnOverview"
android:text="go to overview"/>
</RelativeLayout>
activity_overview.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"
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=".activity.OverviewActivity">
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:onClick="btnLogin"
android:text="go to login"/>
</RelativeLayout>
LoginActivity
package company.useradministration.activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import company.useradministration.R;
public class LoginActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
}
public void btnOverview(View view){
setContentView(R.layout.activity_overview);
}
}
OverviewActivity
package company.useradministration.activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import company.useradministration.R;
public class OverviewActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_overview);
}
public void btnLogin(View view){
setContentView(R.layout.activity_login);
}
}
Okay. When I start the app, I see a button with the text "go to view". After pressing this button, the view changed. Now I see a button with the text "go to overview". When I press this button, the app crashes with the error:
java.lang.IllegalStateException: Could not find method btnOverview(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.resolveMethod(AppCompatViewInflater.java:307)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:266)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18439)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5085)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:611)
at dalvik.system.NativeStart.main(Native Method)
UPDATE:
Here is the explained answer:
You have a activity_overview.xml with it's class OverviewActivity.
In your activity_overview.xml you set the android:onClick="btnLogin" to the button and you have:
public void btnLogin(View view){
setContentView(R.layout.activity_login);
}
in your OverviewActivity so when user clicks this button it changes the contentview successfully.
The question here is:
Why does the app crashes when you click on the button in activity_login.xml to change the contentview back to activity_overview.xml?
Simple. Because you have set the onclick method in your LoginActivity but you aren't switching to that activity but just changing the layout. So when the button to go back to overview content is clicked the app searches for the function in you OverviewActivity because the activity didn't swithed to LoginActivity. It has just changed the content and there is no function called btnOverview in your OverviewActivity. So here you have 2 solutions:
1- Create two RelativeLayouts in just one xml file and than setVisibility of each layouts on button click.
So for that you have to:
Create only one activity instead of two different and in it's xml file use this code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/overview"
android:visibility="gone">
<Button
android:layout_width="wrap_content"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:text="go to login"
android:id="#+id/go_to_login"
android:layout_height="wrap_content" />
//Do your stuff here for overview content
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/login">
<Button
android:layout_width="wrap_content"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:text="go to overview"
android:id="#+id/go_to_overview"
android:layout_height="wrap_content" />
//Do your stuff here for login content
</RelativeLayout>
</RelativeLayout>
This code has 2 RelativeLayouts. The first one with id:overview is of the overview content and it's visibility is gone and the second RelativeLayout with id:login has the visibility visible by default (Change the two layouts visibility as desired).
Than in your MainActivty.java (call it as you wish) you can change the visibility of these views like this:
public class MainActivity extends AppCompatActivity {
Button goToOverview, goToLogin;
RelativeLayout overview, login;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Remember to change the content to match your xml file name
setContentView(R.layout.activity_main);
//Buttons
goToOverview = (Button) findViewById(R.id.go_to_overview);
goToLogin = (Button) findViewById(R.id.go_to_login);
//Layouts
overview = (RelativeLayout) findViewById(R.id.overview);
login = (RelativeLayout) findViewById(R.id.login);
goToOverview.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
login.setVisibility(View.GONE);
overview.setVisibility(View.VISIBLE);
}
});
goToLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
overview.setVisibility(View.GONE);
login.setVisibility(View.VISIBLE);
}
});
}
In this way you can switch to two different layout without any problem.
Edit: You can achieve this also with this solution but the difference between the first solution and this solution is just that you will have 2 xml files instead of one.
2nd- You will have one java class file (in this example I will take OverviewActivityas example) and 2 different layout files (Which you already have: activity_login.xml and activity_overview.xml).
So in your activity_overview.xml change this line: tools:context=".activity.OverviewActivity" to tools:context=".OverviewActivity" as you said that you are using the first folder structure where the OverviewActivity file is out of the activity folder.
Than in your OverviewActivity make the following changes:
public class OverviewActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_overview);
}
public void btnLogin(View view){
setContentView(R.layout.activity_login);
}
public void btnOverview(View view){
setContentView(R.layout.activity_overview);
}
}
That's it. Please comment if you are having any problem with the code. I will be glad to help your further more.
Hope this can solve your issue.
Regards
I think this is your problem:
public void btnOverview(View view){
setContentView(R.layout.activity_overview);
}
This changes the layout for the current activity LoginActivity to activity_overview which contains the button thats looking for the btnLogin method
You are successfully changing the layout, but your staying in the same activity, so the new layout is looking for a method that exists in the other activity
Instead change the above code to this:
public void btnOverview(View view){
Intent intent = new Intent(this, OverviewActivity.class);
startActivity(intent);
}
And in OverviewActivity
public void btnLogin(View view){
Intent intent = new Intent(this, LoginActivity.class);
startActivity(intent);
}
I think you can use this as a help. I'm newbie myself to android java programming, but I believe you have to create intent to move to another activity. Additionally be sure to add your Activity to AndroidManifest.xml. That's all I think. If I'm wrong I'll be happy if someone more experienced will correct me :)

Android - Show image from res/drawable onClick

First of all, I wanna say I've been seeking for an answer on the Forum and I found didn't match for what I wanted. Basically, what I want is: when the user clicks on one of the images previously "specified" on the .xml file, a new image is displayed on the center of the screen that is not "specified" on the .xml file. I wrote "specified" cause idk if it's the correct way to refer to this.
EDIT: there was no need to not specify the image previously, all I needed was to set "gone" for visibiity. This code is working exactly how I wanted (ty guys):
Main.java
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.Toast;
public class Principal extends Activity {
ImageView cuia1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_principal);
cuia1 = (ImageView) findViewById(R.id.cuia1);
cuia1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
ImageView cuia1grande = (ImageView) findViewById(R.id.cuia1grande);
cuia1grande.setVisibility(1);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.principal, menu);
return true;
}
}
activity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/relativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableLayout
android:id="#+id/tableLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:shrinkColumns="*"
android:stretchColumns="*">
<TableRow
android:id="#+id/tabelaCuias"
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:gravity="center">
<TextView
android:id="#+id/selecionaCuia"
android:text="Selecione a cuia"
android:textStyle="bold">
</TextView>
<ImageView
android:id="#+id/cuia1"
android:src="#drawable/cuia1">
</ImageView>
<ImageView
android:id="#+id/cuia2"
android:src="#drawable/cuia2">
</ImageView>
<ImageView
android:id="#+id/cuia3"
android:src="#drawable/cuia3">
</ImageView>
<ImageView
android:id="#+id/cuia4"
android:src="#drawable/cuia4">
</ImageView>
</TableRow>
</TableLayout>
<ImageView
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:layout_centerInParent="true"
android:visibility="gone"
android:id="#+id/cuia1grande"
android:src="#drawable/cuia1grande">
</ImageView>
Is there any reason you don't want to "specify" the image in your layout file? You could place it there and not display it (visibilty="gone"), and then show/hide it when you deem fit.
Here's what I'd do:
Make your layout a RelativeLayout instead of a TableLayout (this will make things easier for showing the image in the center)
Place your TableLayout within the wrapping RelativeLayout
Define an ImageView as the last child within the wrapping RelativeLayout, set centerInParent="true", visibilty="gone"
In your onClick method, simply set its visibility as visible.
If you really don't want to define the ImageView in the layout, then you can create it programmatically:
Follow the same steps 1-2 as before
Capture the reference to the wrapping RelativeLayout in the code
In the onClick method, create the ImageView programatically, specifying the centerInParent="true" via the code (let me know if you want an example on how to do this & I'll edit the answer with a code sample).
Add the new view to the RelativeLayout via myRelativeLayout.addView(myImageView);
Hope this helps :)
public class Principal extends Activity {
ImageView cuia1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_principal);
cuia1 = (ImageView) findViewById(R.id.cuia1);
//set invisible
cuia1 .setVisibility(View.INVISIBLE);
cuia1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
//show image on the center of screen
//set image
cuia1.setImageResource(R.drawable.cuia1);
// set visible
cuia1 .setVisibility(View.VISIBLE);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.principal, menu);
return true;
}
}
import import android.view.View;
Cheerz!

Android: On changing the image on ImageView the Edittext disappeared

I am new to android app development on eclipse IDE.
I am trying to make a basic app in which, on clicking the button both the image in ImageView as well as the text in EditText replaces with another image and text respectively.
But on doing so, primarily when the app starts, a button is displayed on the top, then the ImageView and then the EditText, they work fine, but on clicking the button, only image is replaced successfully while my EditText disappeared. Can you help me out why this happened and how to rectify it?
xml file:
<Button
android:id="#+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/click_it" />
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/button1"
android:layout_below="#+id/button1"
android:src="#drawable/prac" />
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignRight="#+id/imageView1"
android:layout_below="#+id/imageView1"
android:layout_marginTop="30dp"
android:ems="10"
android:text="hello!" >
<requestFocus />
</EditText>
</RelativeLayout>
java file:
package com.example.practicetwo;
import android.os.Bundle;
import android.app.Activity;
import android.view.*;
import android.widget.*;
public class MainActivity extends Activity {
Button b1;
ImageView iv1;
EditText et1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1 = (Button)findViewById(new R.id().button1);
iv1 = (ImageView)findViewById(new R.id().imageView1);
et1 = (EditText)findViewById(new R.id().editText1);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
iv1.setImageResource(R.drawable.prac1);
et1.setText("how r u?");
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
Your image prac1 might be greater than the size of the screen, and as you replace prac with prac1 the EditText is pushed down. Try using LinearLayout instead of RelativeLayout.

Android - error when using ViewFlipper

eveything looks to be fine, but I still get error when I try to change the view by pressing the button.
Here is code:
package com.example.testy;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ViewFlipper;
public class MainActivity extends Activity {
ViewFlipper flipper;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
flipper = (ViewFlipper) findViewById(R.id.viewFlipper1);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public void clcik(View v) {
flipper.showNext();
}
}
And here is my XML:
<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"
android:gravity="top" >
<ViewFlipper
android:id="#+id/viewFlipper1"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="click"
android:text="Button!!" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView!!" />
</ViewFlipper>
</RelativeLayout>
Anyone knows what can be wrong in this code?
Thank you for answers!
Perhaps you should fix the name of your method to click ?
public void **clcik**(View v) {
flipper.showNext();
}
Due the wrong spell (clcik) in our activity code, you may be getting a Exception because Android can't find the click method.
And thanks to #yugidroid's answer I spot one more error on your code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
flipper = (ViewFlipper) findViewById(R.id.viewFlipper1);
setContentView(R.layout.activity_main);
}
You call findViewById before even you have any Views (a call to setContentView) . You will get a NullPointException because of that.
I would recommend you to make a call to super.onCreate the very first line of your onCreate() method. That is what Google does.
Regarding setting the click listener on layout or creating a listener and setting on the code. Well, there is not much difference, although the latter is certainly faster as the first uses reflection, what has a higher cost than just calling a method.
First of all, make sure you call setContentView(R.layout.activity_main); after the super, its a good practice.
Your problem is that you set android:onClick="click" but you are refering the wrong method in Java (clcik doesn't exists).
I advice you to declare and set listeners in the activity, not in the xml.

Categories

Resources