Reputation: 121
Iam a beginner in android project development. I have started developing a basic app using a tutorial i found online. Im using eclipse.There were no errors while running my project. Im getting this error immediately after i click the app on my emulator. Following r d xml and java coding i used:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/tvDisplay"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="@string/result"
android:textSize="30sp" />
<Button
android:id="@+id/a"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="@string/add"
android:textSize="20sp" />
<Button
android:id="@+id/s"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="@string/sub"
android:textSize="20sp" /></LinearLayout>
Java:
package com.app.myapp;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
int count;
Button add,sub;
TextView disp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.linear);
count=0;
add=(Button) findViewById(R.id.a);
sub=(Button) findViewById(R.id.s);
disp=(Button) findViewById(R.id.tvDisplay);
add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
count=count+1;
disp.setText("Result is " + count);
}
});
sub.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
count=count-1;
disp.setText("Result is " + count);
}
});
}
}
Kindly suggest solutions after which I should proceed my project development.
Upvotes: 0
Views: 621
Reputation: 18873
TextView disp;
disp=(Button) findViewById(R.id.tvDisplay);
You have declared 'disp' as a TextView; But in the code you cast it to a Button. Change the cast to TextView like this :
disp=(TextView) findViewById(R.id.tvDisplay);
Upvotes: 1