andriod 用户名和密码

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:padding="3dip"

    >

<!--0固定1可以扩展-->

    <TableLayout

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:numColumns="8"

        android:shrinkColumns="0"

        android:stretchColumns="1">

        <TableRow

            android:layout_width="fill_parent"

            android:layout_height="wrap_content">

            <TextView

                android:id="@+id/label"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="请输入用户名：" />

            <!-- 这个EditText放置在上边id为label的TextView的下边 -->

            <EditText

                android:id="@+id/username"

                android:layout_width="fill_parent"

                android:layout_height="wrap_content"

                android:layout_below="@id/label"

                android:background="@android:drawable/editbox_background" />

        </TableRow>

        <TableRow>

            <TextView

                android:id="@+id/label1"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="密码：" />

            <!-- 这个EditText放置在上边id为label的TextView的下边 -->

            <EditText

                android:id="@+id/pass"

                android:layout_width="fill_parent"

                android:layout_height="wrap_content"

                android:layout_below="@id/label1"

                android:inputType="textPassword"

                android:background="@android:drawable/editbox_background" />

            <CheckBox

                android:id="@+id/checkBox1"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="显示密码" />

        </TableRow>

        <TableRow

            android:layout_width="wrap_content"

            android:layout_height="match_parent">

            <Button

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="确定"

                android:id="@+id/ok"

                android:layout_column="1"

                android:layout_span="1" />

            <Button

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="取消"

                android:id="@+id/cancel"

                android:layout_column="1" />

        </TableRow>

    </TableLayout>

</LinearLayout>

package com.example.yanlei.mytk;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.text.method.HideReturnsTransformationMethod;

import android.text.method.PasswordTransformationMethod;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.CheckBox;

import android.widget.CompoundButton;

import android.widget.CompoundButton.OnCheckedChangeListener;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private TextView passEdit;

    private TextView userNameEdit;

    private CheckBox checkBox1;

    private Button btnok;

    private Button btncancel;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        passEdit = (TextView) findViewById(R.id.pass);

        userNameEdit = (TextView) findViewById(R.id.username);

        checkBox1 = (CheckBox) findViewById(R.id.checkBox1);

        btnok = (Button) findViewById(R.id.ok);

        btncancel = (Button) findViewById(R.id.cancel);

        btncancel.setOnClickListener(new ButtonexitClickListener());

        btnok.setOnClickListener(new ButtonokClickListener());

        checkBox1.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            @Override

            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

                // TODO Auto-generated method stub

                if (isChecked) {

                    //如果选中，显示密码

                    passEdit.setTransformationMethod(HideReturnsTransformationMethod.getInstance());

                } else {

                    //否则隐藏密码

                    passEdit.setTransformationMethod(PasswordTransformationMethod.getInstance());

                }

            }

        });

    }

    private class ButtonexitClickListener implements View.OnClickListener {

        public void onClick(View v) {

            System.exit(0);

        }

    }

    private class ButtonokClickListener implements View.OnClickListener {

        public void onClick(View v) {

            String UserName = userNameEdit.getText().toString();

            String pass = passEdit.getText().toString();

            Toast toast;

            if (UserName.equals("YL") && pass.equals("123")) {

                toast = Toast.makeText(getApplicationContext(), "密码正确" + UserName + ":" + pass, Toast.LENGTH_LONG);

            } else {

                toast = Toast.makeText(getApplicationContext(), "密码错误" + UserName + ":" + pass, Toast.LENGTH_LONG);

            }

            toast.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);

    }

}

优化界面

<?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="wrap_content"

    android:orientation="vertical"

    android:padding="3dip">

    <!--0固定1可以扩展-->

    <TableLayout

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:numColumns="8"

        android:shrinkColumns="0"

        android:stretchColumns="1">

        <TableRow

            android:layout_width="fill_parent"

            android:layout_height="wrap_content">

            <TextView

                android:id="@+id/label"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="请输入用户名：" />

            <!-- 这个EditText放置在上边id为label的TextView的下边 -->

            <EditText

                android:id="@+id/username"

                android:layout_width="fill_parent"

                android:layout_height="wrap_content"

                android:layout_below="@id/label"

                android:background="@android:drawable/editbox_background" />

        </TableRow>

        <TableRow>

            <TextView

                android:id="@+id/label1"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="密码：" />

            <!-- 这个EditText放置在上边id为label的TextView的下边 -->

            <EditText

                android:id="@+id/pass"

                android:layout_width="fill_parent"

                android:layout_height="wrap_content"

                android:layout_below="@id/label1"

                android:background="@android:drawable/editbox_background"

                android:inputType="textPassword" />

            <CheckBox

                android:id="@+id/checkBox1"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="显示密码" />

        </TableRow>

        <TableRow

            android:layout_width="wrap_content"

            android:layout_height="match_parent">

        </TableRow>

    </TableLayout>

    <LinearLayout

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal"

        android:padding="5dip"

        android:gravity="right"

        android:weightSum="1">

        <Button

            android:id="@+id/ok"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_weight="0.20"

            android:text="确定"

            android:layout_marginRight="20dip" />

        <Button

            android:id="@+id/cancel"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="取消"

            android:layout_weight="0.20"

            android:hint="退出"

            android:clickable="true" />

    </LinearLayout>

</LinearLayout>

=======================================================

又一个登陆界面

<?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:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:textAlignment="center"

        android:text="用户登录界面"

        android:autoText="false"

        android:gravity="center" />

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal" >

        <TextView

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="用户名    :" />

        <EditText

            android:id="@+id/editText1"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:hint="请输入用户名" />

    </LinearLayout>

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal" >

        <TextView

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="密        码:" />

        <EditText

            android:id="@+id/editText2"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:hint="请输入密码"

            android:layout_weight="1"

            android:inputType="textPassword" />

        <CheckBox

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="显示密码"

            android:id="@+id/checkBox" />

    </LinearLayout>

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal" >

    </LinearLayout>

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content" >

        <Button

            android:id="@+id/btn_confirm"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="确认" />

        <Button

            android:id="@+id/btn_back"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="返回" />

    </LinearLayout>

    <ImageView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/imageView"

        android:layout_gravity="center_horizontal" />

</LinearLayout>