package com.example.qq;

import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity implements OnClickListener  {
    TextView textView;
    EditText username;
    EditText password;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        username = (EditText) findViewById(R.id.username);
        password = (EditText) findViewById(R.id.password);
        textView = (TextView) findViewById(R.id.textView1);
        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        String username1 = username.getText().toString();
        String password1 = password.getText().toString();
        // TODO Auto-generated method stub
          if (username1.equals("123456") && password1.equals("123456")) {
               Intent intent = new Intent();    
               intent.setClass(MainActivity.this, secendActivity.class);
                Bundle bundle = new Bundle();
                bundle.putString("username1", "123456");
                bundle.putString("password1", "123456");
                intent.putExtras(bundle);
                startActivity(intent);
               finish();
            }
          if (!username1.equals("123456") && !password1.equals("123456")) {
                String s="登录失败";
                textView.setText(s);

        }
    }

    
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    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.qq.MainActivity" >

    <TextView
        android:id="@+id/tv_account"
        android:layout_width="fill_parent"
        android:layout_height="40dp"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" 
        android:background="#FFFFFF"
        android:text="帐号:"
        android:textSize="30dp"
 
        />
     <TextView
         android:id="@+id/tv_account1"
         android:layout_width="fill_parent"
         android:layout_height="40dp"
         android:layout_below="@+id/tv_account"
         android:layout_centerVertical="true"
         android:background="#FFFFFF"
         android:text="密码:"
         android:textSize="30dp"
         
          />

     <Button
         android:id="@+id/button1"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:layout_alignLeft="@+id/tv_account1"
         android:layout_alignRight="@+id/tv_account1"
         android:layout_below="@+id/tv_account1"
         android:background="#545bcb"
         android:textColor="#ffffff"
         android:textSize="20dp"
         android:text="登录" 
         android:onClick="CCC"/>

     <ImageView
         android:id="@+id/imageView1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerHorizontal="true"
         android:layout_above="@+id/tv_account"
         android:src="@drawable/logo" />

     <EditText
         android:id="@+id/password"
         android:layout_width="400dp"
         android:layout_height="40dp"
         android:layout_below="@+id/tv_account"
         android:ems="10" 
         android:gravity="center"
         android:background="@null"
         />

     <EditText
         android:id="@+id/username"
         android:layout_width="match_parent"
         android:layout_height="40dp"
         android:layout_centerInParent="true"
         android:ems="10"
         android:gravity="center"
         android:background="@null"
          />

     <TextView
         android:id="@+id/textView1"
         android:layout_width="400dp"
         android:layout_height="40dp"
         android:layout_centerHorizontal="true"
         android:layout_below="@+id/button1" />

</RelativeLayout>

package com.example.qq;
import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class secendActivity extends ActionBarActivity  {
    TextView tv2;
    TextView tv4;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.secend);
        Intent intent = getIntent();
        Bundle bundle=intent.getExtras();//.getExtras()得到intent所附带的额外数据  
        String uname=bundle.getString("username1");
        String upwd=bundle.getString("password1");
        tv2=(TextView) findViewById(R.id.textView2);  
        tv4=(TextView) findViewById(R.id.textView4);    
        tv2.setText(uname);
        tv4.setText(upwd);
        
}

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    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.qq.secendActivity" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:text="你的账号是:" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView1"
        android:layout_alignBottom="@+id/textView1"
        android:layout_marginLeft="28dp"
        android:layout_toRightOf="@+id/textView1"
        android:text="" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="17dp"
        android:text="你的密码是:" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView3"
        android:layout_alignBottom="@+id/textView3"
        android:layout_marginLeft="14dp"
        android:layout_toRightOf="@+id/textView3"
        android:text="" />

</RelativeLayout>