Reputation: 916
I'm new to Android and I was practicing, when i finished this practice app i ran it but it says "unfortunately has stopped" where is the problem?My app looks like a simple log in screen and i don't think there's a problem with the XML file.
package com.mycompany.testbutton;
import android.media.Image;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
Button buttonLog = (Button)findViewById(R.id.button1);
EditText userName = (EditText)findViewById(R.id.usernameText);
EditText passWord = (EditText)findViewById(R.id.passwordText);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonLog.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String username = String.valueOf(userName.getText());
String password = String.valueOf(passWord.getText());
String allTogetherToast = "Your Email is " + username + " and your Password is " + password;
Toast.makeText(MainActivity.this, allTogetherToast, Toast.LENGTH_LONG).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Upvotes: 1
Views: 10643
Reputation: 47817
Move
Button buttonLog = (Button)findViewById(R.id.button1);
EditText userName = (EditText)findViewById(R.id.usernameText);
EditText passWord = (EditText)findViewById(R.id.passwordText);
after setContentView(....)
inside onCreate(...)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button buttonLog = (Button)findViewById(R.id.button1);
EditText userName = (EditText)findViewById(R.id.usernameText);
EditText passWord = (EditText)findViewById(R.id.passwordText);
Views
available only after setContentView(....)
Upvotes: 2
Reputation: 1147
Initialize these
Button buttonLog = (Button)findViewById(R.id.button1);
EditText userName = (EditText)findViewById(R.id.usernameText);
EditText passWord = (EditText)findViewById(R.id.passwordText);
after your
setContentView(R.layout.activity_main)
so your code will be like this
package com.mycompany.testbutton;
import android.media.Image;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
Button buttonLog;
EditText userName;
EditText passWord;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonLog = (Button)findViewById(R.id.button1);
userName = (EditText)findViewById(R.id.usernameText);
passWord = (EditText)findViewById(R.id.passwordText);
buttonLog.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String username = String.valueOf(userName.getText());
String password = String.valueOf(passWord.getText());
String allTogetherToast = "Your Email is " + username + " and your Password is " + password;
Toast.makeText(MainActivity.this, allTogetherToast, Toast.LENGTH_LONG).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
Upvotes: 3