EventHandling not working with button

[vinoth vino]

Hello friends.... I'm new to Android programming and now i just simply create one button with listener and one multiline text(I searched a lot whether the edittext is available in the right pane but there were no edittext there. so i'm using multiline text in this activity and i've change the layout resource ot text then in that edittext tag is present). if i click this button then i want to display the content which I've set up in the edittext variable

MainActivity.java

package com.example.vinothvino.sample;

import android.os.Bundle;
import android.app.Activity;
import android.view.Window;
import android.view.WindowManager;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {

      EditText editText;
      Button button;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);  //it hides only the title

        //getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        editText = (EditText)findViewById(R.id.editText);
        button = (Button)findViewById(R.id.button);

        setContentView(R.layout.activity_main);
    }
    public void onClick(View v){
        editText.setText("Welcome to Android World");
    }
}

AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.vinothvino.sample" > <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" android:screenOrientation="portrait"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>

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" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge" android:text="Vino" android:id="@+id/textView" android:layout_alignParentTop="true" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" /> <EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:inputType="textMultiLine" android:ems="10" android:id="@+id/editText" android:layout_marginTop="70dp" android:layout_below="@+id/textView" android:layout_centerHorizontal="true" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Button" android:id="@+id/button" android:layout_centerVertical="true" android:layout_centerHorizontal="true" /> </RelativeLayout>
Thanks in advance
Sorry for my english

[Simon Roberts]

Normally, I'd shut up, since I'm not much of an android person. However, as best I recall, the behavior of components in Android mimics that of typical components in "regular Java". If that's the case, then you actually need to a) make the code that includes the cliick handler "implement Xxxx" where Xxxx is the name of the expected listener for the button, and you need to do something like addActionListener(myXxxx) to attach the listener directly to the source of events.

Hope this helps, sorry if it's a total red herring. As I say, I tinkered with Android some years ago, and I vaguely recall it had "the usual structure, Might be embarrassingly wrong though.

[Ron McLeod]

You need to specify a onClick handler for the button - either in the layout file with an android:onClick attribute, or programmatically with the button's setOnClickListener() method.

Take a look at the Button API reference for more information.

[vinoth vino]

Thank you Ron!!! I did it with setOnClickListener method also but i got error only. At last I figured out that I wanna declare the buttons,EditText after the setContentView method. Thanks a lot ron