保存文件到手机内存与使用密码登陆_would存档手机登录-优快云博客

本文介绍了一个简单的Android登录界面实现过程，包括XML布局设计、Activity交互逻辑及用户信息存储与读取的方法。通过LinearLayout布局和EditText组件实现了用户名和密码输入功能，并使用CheckBox控制密码存储选项。

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1：xml文件的代码:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="请输入用户名" />

    <EditText
        android:id="@+id/et_usename"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="请输入密码" />

    <EditText
        android:inputType="textPassword"
        android:id="@+id/password"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" >

        <CheckBox
            android:id="@+id/cb_remenber_passward"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="记住密码" />

        <Button
            android:layout_alignParentRight="true"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="login"
            android:text="登陆" >
        </Button>
    </RelativeLayout>

</LinearLayout>

2:对应的类文件：

package com.example.shenchao2;


import java.util.Map;


import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;


import com.example.shenchao2.service.LoginService;


public class MainActivity extends Activity {


<span style="white-space:pre">	</span>private static final String TAG = "MainActivity";
<span style="white-space:pre">	</span>private EditText ed_usename;
<span style="white-space:pre">	</span>private EditText ed_password;
<span style="white-space:pre">	</span>private CheckBox cb;


<span style="white-space:pre">	</span>@Override
<span style="white-space:pre">	</span>protected void onCreate(Bundle savedInstanceState) {
<span style="white-space:pre">		</span>super.onCreate(savedInstanceState);
<span style="white-space:pre">		</span>setContentView(R.layout.activity_main);
<span style="white-space:pre">		</span>ed_usename = (EditText) this.findViewById(R.id.et_usename);
<span style="white-space:pre">		</span>ed_password = (EditText) this.findViewById(R.id.password);
<span style="white-space:pre">		</span>cb = (CheckBox) this.findViewById(R.id.cb_remenber_passward);
<span style="white-space:pre">		</span>//控制回显的代码
<span style="white-space:pre">		</span>Map<String,String> map = LoginService.getSaveUserInfo(this);
<span style="white-space:pre">		</span>if (map!=null) {
<span style="white-space:pre">			</span>ed_usename.setText(map.get("usename"));//设置密码和用户名
<span style="white-space:pre">			</span>ed_password.setText(map.get("password"));
<span style="white-space:pre">		</span>}
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>/**
<span style="white-space:pre">	</span> * 登陆成功
<span style="white-space:pre">	</span> * @param vew
<span style="white-space:pre">	</span> */
<span style="white-space:pre">	</span>public void login(View vew) {
<span style="white-space:pre">		</span>String usename = ed_usename.getText().toString().trim();
<span style="white-space:pre">		</span>String password = ed_password.getText().toString().trim();// 将其内容拿出来
<span style="white-space:pre">		</span>// 判断是否为空
<span style="white-space:pre">		</span>if (TextUtils.isEmpty(usename) || TextUtils.isEmpty(password)) {
<span style="white-space:pre">			</span>Toast.makeText(this, "不能为空", Toast.LENGTH_LONG).show();
<span style="white-space:pre">		</span>} else {
<span style="white-space:pre">			</span>// 登陆,是否保存密码
<span style="white-space:pre">			</span>if (cb.isChecked()) {
<span style="white-space:pre">				</span>// 保存用户密码
<span style="white-space:pre">				</span>Log.i(TAG, "需要保存用户密码!");//日志文件信息
<span style="white-space:pre">				</span>boolean result = LoginService.saveUseInfo(this, usename,
<span style="white-space:pre">						</span>password);
<span style="white-space:pre">				</span>if (result) {
<span style="white-space:pre">					</span>Toast.makeText(this, "好高兴,保存成功!", Toast.LENGTH_LONG).show();
<span style="white-space:pre">				</span>}
<span style="white-space:pre">			</span>}
<span style="white-space:pre">			</span>// 登陆发送消到服务器,服务器验证是否正确
<span style="white-space:pre">			</span>if ("zhangsan".equals(usename) && "123".equals(password)) {
<span style="white-space:pre">				</span>Toast.makeText(this, "登陆成功!", Toast.LENGTH_LONG).show();
<span style="white-space:pre">			</span>} else {
<span style="white-space:pre">				</span>Toast.makeText(this, "登陆失败!", Toast.LENGTH_LONG).show();
<span style="white-space:pre">			</span>}
<span style="white-space:pre">		</span>}
<span style="white-space:pre">	</span>}
}

3：LoginService：

package com.example.shenchao2.service;


import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;


import android.content.Context;


public class LoginService {


<span style="white-space:pre">	</span>public static boolean saveUseInfo(Context context, String usename,
<span style="white-space:pre">			</span>String password) {
<span style="white-space:pre">		</span>try {
<span style="white-space:pre">			</span>// File file = new
<span style="white-space:pre">			</span>// File("/data/data/com.example.shenchao2/info.txt");
<span style="white-space:pre">			</span>// context.getFilesDir(); //帮助我们返回一个目录 data/data/包名/files/
<span style="white-space:pre">			</span>File file = new File(context.getFilesDir(), "info.txt");
<span style="white-space:pre">			</span>// File file1 = new File(context.getCacheDir(),
<span style="white-space:pre">			</span>// "info.txt");//帮助我们返回一个目录 data/data/包名/Cache/
<span style="white-space:pre">			</span>FileOutputStream fos = new FileOutputStream(file);
<span style="white-space:pre">			</span>fos.write((usename + "##" + password).getBytes());// getBytes()是将一个字符串转化为一个字节数组。
<span style="white-space:pre">			</span>fos.close();
<span style="white-space:pre">			</span>return true;
<span style="white-space:pre">		</span>} catch (Exception e) {
<span style="white-space:pre">			</span>e.printStackTrace();
<span style="white-space:pre">			</span>return false;
<span style="white-space:pre">		</span>}
<span style="white-space:pre">	</span>}


<span style="white-space:pre">	</span>/**
<span style="white-space:pre">	</span> * 获取保存的数据
<span style="white-space:pre">	</span> * 
<span style="white-space:pre">	</span> * @param context
<span style="white-space:pre">	</span> */
<span style="white-space:pre">	</span>public static Map<String, String> getSaveUserInfo(Context context) {


<span style="white-space:pre">		</span>File file = new File(context.getFilesDir(), "info.txt");
<span style="white-space:pre">		</span>try {
<span style="white-space:pre">			</span>FileInputStream fis = new FileInputStream(file);
<span style="white-space:pre">			</span>// 缓冲当前的数据
<span style="white-space:pre">			</span>BufferedReader br = new BufferedReader(new InputStreamReader(fis));
<span style="white-space:pre">			</span>String str = br.readLine(); // 读取第一行的数据
<span style="white-space:pre">			</span>String[] infos = str.split("##");// 分割开
<span style="white-space:pre">			</span>Map<String, String> map = new HashMap<String, String>(); // 初始化map
<span style="white-space:pre">			</span>map.put("usename", infos[0]);
<span style="white-space:pre">			</span>map.put("password", infos[1]);
<span style="white-space:pre">			</span>return map;
<span style="white-space:pre">		</span>} catch (Exception e) {
<span style="white-space:pre">			</span>e.printStackTrace();
<span style="white-space:pre">			</span>return null;
<span style="white-space:pre">		</span>}


<span style="white-space:pre">	</span>}
}
}