android 学生选课系统app源码(sqlite数据库,入门级)

【实例简介】

【实例截图】

【核心代码】

package com.example.student;


import com.example.student.MainActivity;
import com.example.student.RegisterActivity;
import com.example.dao.UserService;
import com.example.guanli.Gl;

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

public class MainActivity extends Activity {

	// 分别为用户名和密码
	private EditText mUsername;
	private EditText mPassword;
	// 分别为登陆和注册按钮
	private Button mLogin;
	private Button mRegister;
	private Button m;
	private Button a;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		mUsername = (EditText) findViewById(R.id.username);
		mPassword = (EditText) findViewById(R.id.password);

		mLogin = (Button) findViewById(R.id.button1);
		mRegister = (Button) findViewById(R.id.button2);
		m = (Button) findViewById(R.id.button3);
		a = (Button) findViewById(R.id.button4);
		// 登陆
		mLogin.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {
				String userName = mUsername.getText().toString().trim();
				String passWord = mPassword.getText().toString().trim();

				UserService userService = new UserService(MainActivity.this);
				if (mUsername.getText().toString().trim().equals("")) 	{
					Toast.makeText(getApplicationContext(), "账户名不能为空！",
							Toast.LENGTH_SHORT).show();
					return;
				}
				if (mPassword.getText().toString().equals("")) {
					Toast.makeText(getApplicationContext(), "密码不能为空！",
							Toast.LENGTH_SHORT).show();
					return;
				}
				boolean flag = userService.Login(userName, passWord);
				if (flag) {
					Toast.makeText(MainActivity.this, "登录成功！",
							Toast.LENGTH_SHORT).show();
					Intent intent = new Intent();
					intent.setClass(MainActivity.this,
							YhuMainActivity.class);
					startActivity(intent);
				} else {
					Toast.makeText(MainActivity.this, "登录失败！",
							Toast.LENGTH_SHORT).show();
				}

			}
		});

		// 注册
		mRegister.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {

				Intent intent = new Intent();
				intent.setClass(MainActivity.this, RegisterActivity.class);
				startActivity(intent);
			}
		});
		//退出
	m.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View arg0) {
				finish();
			}
		});
	
	//管理
	a.setOnClickListener(new OnClickListener() {
		@Override
		public void onClick(View arg0) {
			Intent intent = new Intent();
			intent.setClass(MainActivity.this, Gl.class);
			startActivity(intent);
		}
	});
	}


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}