android入门--------案例一（登陆客户端）

<?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:orientation="vertical" >

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="帐户："
android:textSize="18dp"
/>
<EditText
android:id="@+id/account"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="密码："
android:textSize="18dp"
/>
<EditText
android:id="@+id/password"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:password="true"
/>
<Button
android:id="@+id/login"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="18dp"
android:text="马 上 登 陆"
/>
</LinearLayout>

package com.xiagqiao.app_login.activity;

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

public class LoginActivity extends Activity {
/** Called when the activity is first created. */
private EditText account;
private EditText password;
private Button login;

private OnClickListener listener=new OnClickListener(){

public void onClick(View v) {
if(v.getId()==R.id.login){
String ac=account.getText().toString().trim();
String ps=password.getText().toString().trim();

if(ac.equals("admin") && ps.equals("admin")){
Toast.makeText(LoginActivity.this, "success", Toast.LENGTH_LONG).show();
}else{
Toast.makeText(LoginActivity.this, "failed", Toast.LENGTH_LONG).show();
}

}

}
};

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

account= (EditText) findViewById(R.id.account);
password= (EditText) findViewById(R.id.password);
login= (Button) findViewById(R.id.login);

login.setOnClickListener(listener);
}
}