Android入门之login设计

效果图：

MainActivity.java

package jk.quickpay.login;

import jk.quickpay.login.FileService;
import java.util.Map;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

	public EditText edit_name, edit_pass;
	public Button btn_login;
	public CheckBox box_remeber;
	public FileService fileService;

	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		fileService = new FileService(this);

		edit_name = (EditText) findViewById(R.id.edit_name);
		edit_pass = (EditText) findViewById(R.id.edit_pass);
		btn_login = (Button) findViewById(R.id.btn_login);
		box_remeber = (CheckBox) findViewById(R.id.cbx_remember);

		btn_login.setOnClickListener(new MyOnClickListener());

		Map<String, String> map = fileService.readFile("private.txt");
		if (map != null) {
			edit_name.setText(map.get("name"));
			edit_pass.setText(map.get("pass"));
		}
	}

	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	class MyOnClickListener implements View.OnClickListener {

		public void onClick(View v) {
			int id = v.getId();
			switch (id) {
			case R.id.btn_login:
				String name = edit_name.getText().toString();
				String pass = edit_pass.getText().toString();
				if (TextUtils.isEmpty(name)) {
					Toast.makeText(MainActivity.this, "用户名不能为空",
							Toast.LENGTH_SHORT).show();
					return;
				} else if (TextUtils.isEmpty(pass)) {
					Toast.makeText(MainActivity.this, "密码不能为空",
							Toast.LENGTH_SHORT).show();
					return;
				} else {
					if (box_remeber.isChecked()) {
						MainActivity.this.fileService.saveToRom(name, pass,
								"private.txt");
						Toast.makeText(MainActivity.this, "用户名和密码已保存",
								Toast.LENGTH_SHORT).show();
					} else {
						Toast.makeText(MainActivity.this, "用户名和密码不需要保存",
								Toast.LENGTH_SHORT).show();
					}
				}
				break;
			default:
				break;
			}
		}
	}
}

FileService.java

package jk.quickpay.login;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.HashMap;
import java.util.Map;

import jk.quickpay.login.StreamTools;

import android.content.Context;

public class FileService {

	public Context context;

	public FileService(Context context) {
		this.context = context;
	}

	public boolean saveToRom(String name,String pass,String fileName){
		try{
			FileOutputStream fos=context.openFileOutput(fileName, Context.MODE_PRIVATE);
			String result=name+":"+pass;
			fos.write(result.getBytes());
			fos.flush();
			fos.close();
		}catch(Exception e){
			e.printStackTrace();
			return false;
		}
		return true;
	}

	public Map<String,String> readFile(String fileName){
		Map<String,String> map=null;
		try{
			FileInputStream fis=context.openFileInput(fileName);
			String value=StreamTools.getValue(fis);
			String values[]=value.split(":");
			if(values.length>0){
				map=new HashMap<String, String>();
				map.put("name", values[0]);
				map.put("pass", values[1]);
			}

		}catch(Exception e){
			e.printStackTrace();
		}
		return map;
	}

}

StreamTools.java

package jk.quickpay.login;

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;

public class StreamTools {
	public static String getValue(FileInputStream fis) throws Exception{
		ByteArrayOutputStream stream=new ByteArrayOutputStream();
		byte[] buffer=new byte[1024];
		int length=-1;
		while((length=fis.read(buffer))!=-1){
			stream.write(buffer,0,length);
		}
		stream.flush();
		stream.close();
		String value=stream.toString();
		return value;
	}
}

activity_main.xml

<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: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=".LoginActivity" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:orientation="vertical" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/view_account"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/account" />

            <EditText
                android:id="@+id/edit_name"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:ems="10"
                android:inputType="textPersonName" >

                <requestFocus />
            </EditText>
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/view_pass"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/password" />

            <EditText
                android:id="@+id/edit_pass"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:ems="10"
                android:inputType="textPassword" />
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <Button
                android:id="@+id/btn_login"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0.1"
                android:text="@string/login" />
             <Button
                android:id="@+id/btn_reg"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0.1"
                android:text="@string/register" />
              <Button
                android:id="@+id/btn_out"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0.1"
                android:text="@string/quit" />

        </LinearLayout>

            <CheckBox
                android:id="@+id/cbx_remember"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="80dp"
                android:text="@string/text_rember" />
    </LinearLayout>

</LinearLayout>