一个Android登陆的简单实现

     在公司实习半个月了，上个星期开始接触Android，做了一个很简单的登陆实现。有三个Activity，一个是Login的Activity，一个是正确登陆后的Activity，最后一个是登陆错误后的Activity。其中registerButton没写，因为我还没看android.database这个包，以后我会慢慢的完善它。还有就是检测用户名和密码，用的是最最简陋的equals来判断的，还是因为我没看android.database，呵呵。我现在还是新手，如果哪里有写的不好的，或者是不完善的，请大家多多批评。谢谢大家！下面是全部代码。代码我上传到附件，欢迎下载。

Login.java

package com.heji.login;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class Login extends Activity {
	/** Called when the activity is first created. */
    
	private static Button loginButton;
	private static Button cancelButton;
	private static Button registerButton;
	private static Button exitButton;
    private ButtonListener bl = new ButtonListener();
    
    private EditText et1;
    private EditText et2;
    private Intent intent;
	@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);
        
        //添加登陆按钮监听
        loginButton = (Button)findViewById(R.id.login_ok);
        loginButton.setOnClickListener(bl);

        //添加取消按钮监听
        cancelButton = (Button)findViewById(R.id.login_reset);
        cancelButton.setOnClickListener(bl);
      
        //添加注册按钮监听
        registerButton = (Button)findViewById(R.id.register);
        registerButton.setOnClickListener(bl);
       
        //添加退出按钮监听
        exitButton = (Button)findViewById(R.id.exit); 
        exitButton.setOnClickListener(bl);
    }
	 private class ButtonListener implements View.OnClickListener {
			public void onClick(View view) {
				// TODO Auto-generated method stub
				if(view == loginButton) {
					et1 = (EditText)findViewById(R.id.username_info);
					et2 = (EditText)findViewById(R.id.password_info);
					 
					if((et1.getText().toString()).equals("heji") && (et2.getText().toString()).equals("heji")) {
						intent = new Intent();
						
						//用Bundle来传递当前Activity的内容
						Bundle bundle = new Bundle();
						bundle.putString("USERNAME", et1.getText().toString());
						intent.putExtras(bundle);
						
						intent.setClass(Login.this, Information.class);
						
						//启动Activity
						startActivity(intent);
					}else {
	                    intent = new Intent();
						
						intent.setClass(Login.this, ErrorPage.class);
						//启动Activity
						startActivity(intent);
					}
				}else if(view == cancelButton) {
					intent = new Intent();
					//通过Login这个类来启动Login
					intent.setClass(Login.this, Login.class);
					//启动Activity
					startActivity(intent);
				}else if(view == registerButton) {
					
				}else if(view == exitButton) {
				    finish();
				}
			}
     }
}

Information.java(名字取得很不好，见谅)

package com.heji.login;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class Information extends Activity {

	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		//显示布局
		this.setContentView(R.layout.information);
		
		TextView tv = (TextView)findViewById(R.id.first_page_info);
		
		//获得从上个页面传过来的数据
		Bundle bundle = this.getIntent().getExtras();
		String str = bundle.getString("USERNAME");
		tv.setText(str);
		
		Button button_back = (Button)findViewById(R.id.back);
		button_back.setOnClickListener(new View.OnClickListener() {
			public void onClick(View view) {
				// TODO Auto-generated method stub
				Intent intent = new Intent();
				
				//通过Information这个类来启动Login
				intent.setClass(Information.this, Login.class);
				//启动Activity
				startActivity(intent);
			}
		});
	}
}

ErrorPage.java

package com.heji.login;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;



public class ErrorPage extends Activity {

	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		//显示布局
		this.setContentView(R.layout.errorpage);
		
		Button button_back = (Button)findViewById(R.id.errorback);
		button_back.setOnClickListener(new View.OnClickListener() {
			public void onClick(View view) {
				// TODO Auto-generated method stub
				Intent intent = new Intent();
				
				//通过ErrorPage这个类来启动Login
				intent.setClass(ErrorPage.this, Login.class);
				//启动Activity
				startActivity(intent);
			}
		});
	}
}

下面是布局文件：
login.xml

<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/welcome_hello"
    />
    
    <TableRow android:orientation="horizontal"
                  android:layout_width="fill_parent" 
                  android:layout_height="wrap_content">
                  
         <TextView   
             android:layout_width="fill_parent" 
             android:layout_height="wrap_content"
             android:text="@string/username"
         />
         
         <EditText android:id="@+id/username_info"
             android:maxLength="8"
             android:maxLines="1"
             android:layout_weight="1.0"
             android:layout_width="fill_parent" 
             android:layout_height="wrap_content"
             android:text=""
         />
    </TableRow>
    
    <TableRow android:orientation="horizontal"
                  android:layout_width="fill_parent" 
                  android:layout_height="wrap_content">
                  
         <TextView 
             android:layout_width="fill_parent" 
             android:layout_height="wrap_content"
             android:text="@string/password"
         />
         
         <EditText android:id="@+id/password_info"
             android:password="true"
             android:maxLength="10"
             android:maxLines="1"
             android:layout_weight="1.0"
             android:layout_width="fill_parent" 
             android:layout_height="wrap_content"
             android:text=""
         />
    </TableRow>
    
     <LinearLayout android:orientation="horizontal"
                   android:layout_width="fill_parent" 
                   android:layout_height="wrap_content">
                  
           <Button android:id="@+id/login_ok"
                   android:layout_width="fill_parent" 
                   android:layout_height="wrap_content"
                   android:layout_weight="1.0"
                   android:text="@string/login"
           />
           
           <Button android:id="@+id/login_reset"
                   android:layout_width="fill_parent" 
                   android:layout_height="wrap_content"
                   android:layout_weight="1.0"
                   android:text="@string/reset"
           />
    </LinearLayout>
    
     <LinearLayout android:orientation="horizontal"
                   android:layout_width="fill_parent" 
                   android:layout_height="wrap_content">
                  
           <Button android:id="@+id/register"
                   android:layout_width="fill_parent" 
                   android:layout_height="wrap_content"
                   android:layout_weight="1.0"
                   android:text="@string/register"
           />
           <Button android:id="@+id/exit"
                   android:layout_width="fill_parent" 
                   android:layout_height="wrap_content"
                   android:layout_weight="1.0"
                   android:text="@string/exit"
           />
    </LinearLayout>
    
</TableLayout>

information.xml

<?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"
    >
    
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/success_info"
    />
    
<TextView  android:id="@+id/first_page_info"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text=""
    />
    
<Button android:id="@+id/back"
          android:layout_width="fill_parent" 
          android:layout_height="wrap_content"
          android:text="@string/back"
  />

</LinearLayout>

errorpage.xml

<?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"
    >
    
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/errorpage"
    />
<Button android:id="@+id/errorback"
              android:layout_width="60dip" 
              android:layout_height="wrap_content"
              android:text="@string/error_back"
      />
</LinearLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="welcome_hello">Hello,Welcome To Login</string>
    <string name="app_name">Login</string>
    <string name="username">username</string>
    <string name="password">password</string>
    <string name="login">login</string>
    <string name="reset">reset</string>
    <string name="register">register</string>
    <string name="information">congratulation!</string>
    <string name="success_info">Hello Android Developer,You ID Is</string>
    <string name="errorpage">Sorry,You Don't Register,Please By The "BACK" Button To Return The FirstPage,Thank You!!!</string>
    <string name="error_back">BACK</string>
    <string name="back">BACK</string>
    <string name="exit">Exit</string>
</resources>

评论

4 楼 diyisoft 2009-07-01  

记得要更新AndroidManifest.xml这个文件哦

3 楼 william_zhg 2009-03-27  

不错，我现在也是正在学习android呢。如有问题还需解疑呀～～谢谢

2 楼 heji 2009-03-11  

ixfire 写道

顶 不错的啊

谢谢！我上个星期才开始写代码，以前也只是看看API，以后我会更加努力的

1 楼 ixfire 2009-03-11  

顶 不错的啊