AndriodStudio实现简单学生管理
修24352 人气:2数据库的创建
package com.example.myapp; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.widget.Toast; public class DbHelper extends SQLiteOpenHelper { final String create_table="CREATE TABLE Student (_id integer primary key autoincrement,xm text,xh text,bj text,zy text,cj text)"; final String create_register="CREATE TABLE Register (_id integer primary key autoincrement,xm text,xh text)"; //创建两张表,一张student,一张register表 Context context; public DbHelper(Context context,String dbname,int version){ super(context,dbname,null,version); this.context=context;//上下文 } @Override public void onCreate(SQLiteDatabase db) {db.execSQL(create_table); db.execSQL(create_register);} @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { db.execSQL("drop table if exists Student"); db.execSQL("drop table if exists Register"); db.execSQL(create_table); db.execSQL(create_register); //完成创建 } // 对表进行数据的插入方法 public void insert(String tableName, ContentValues values){ SQLiteDatabase db = getReadableDatabase(); db.insert(tableName,null,values); Toast.makeText(context,"成功插入数据!",Toast.LENGTH_SHORT).show(); } //查询表中所有 public Cursor queryAll(String tableName){ SQLiteDatabase db = getReadableDatabase(); Cursor cursor = db.query(tableName,null,null,null,null,null,null); return cursor; } //对表中的姓名和学号进行单独的查询 public Boolean queryByStudentXhAndXm(String tableName,String xm,String xh){ SQLiteDatabase db = getReadableDatabase(); Cursor cursor = db.query(tableName,new String[]{"xm,xh"},"xm=? and xh=?",new String[]{xm,xh},null,null,null); if (cursor.moveToFirst()) { return true; }else { return false; } } //删除表中数据的方法 public void delStudent(String id){ SQLiteDatabase db = getWritableDatabase(); db.delete("Student","_id=?",new String[]{id}); } //对表进行更新 public void updateStudent(String id,ContentValues values){ SQLiteDatabase db = getWritableDatabase(); db.update("Student",values,"_id=?",new String[]{id}); } }
创建了两张表格,一张用来储存学生信息,Student表:id(主键),姓名,学号,班级,专业,成绩。
一张register表:id(主键),姓名,学号。用来储存登录信息
其余类和其布局文件
MainActivity.class(登录界面)
package com.example.myapp; import androidx.appcompat.app.AppCompatActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends AppCompatActivity { EditText et1,et2; Button btn1,btn2; DbHelper dbHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); dbHelper=new DbHelper(MainActivity.this,"MyDataBase,",3); setContentView(R.layout.activity_main); et1=findViewById(R.id.et1); et2=findViewById(R.id.et2); btn1=findViewById(R.id.dl); btn2=findViewById(R.id.zc); btn1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String xm=et1.getText().toString(); String xh=et2.getText().toString(); if (xm.isEmpty()||xh.isEmpty()){ Toast.makeText(MainActivity.this,"姓名或者学号不可为空",Toast.LENGTH_SHORT).show(); } if (dbHelper.queryByStudentXhAndXm("Register",xm,xh)){ Intent intent=new Intent(MainActivity.this,Manage.class); startActivity(intent); } } }); btn2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent=new Intent(MainActivity.this,Register.class); startActivity(intent); } }); } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et1" android:hint="输入姓名"/> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et2" android:hint="学号"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/dl" android:text="登录"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="注册" android:id="@+id/zc"/> </LinearLayout>
Register.class(注册界面)
package com.example.myapp; import androidx.appcompat.app.AppCompatActivity; import android.content.ContentValues; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.text.TextUtils; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class Register extends AppCompatActivity { EditText et1,et2; Button btn1,btn2; DbHelper dbHelper; TextView show; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_register); dbHelper=new DbHelper(Register.this,"MyDataBase,",3); et1=findViewById(R.id.xm_zc); et2=findViewById(R.id.xh_zc); show=findViewById(R.id.tv_show); btn1=findViewById(R.id.qd_zc); btn2=findViewById(R.id.fh); btn1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String xm=et1.getText().toString(); String xh=et2.getText().toString(); if(TextUtils.isEmpty(xm)||TextUtils.isEmpty(xh)){ Toast.makeText(Register.this,"姓名或者学号不能为空",Toast.LENGTH_SHORT).show(); return; } ContentValues values = new ContentValues(); values.put("xm",xm); values.put("xh",xh); dbHelper.insert("Register",values); showUser(); } }); btn2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent=new Intent(Register.this,MainActivity.class); startActivity(intent); } }); } public void showUser(){ Cursor cursor = dbHelper.queryAll("Register"); String str = "_id xm xh\n"; if (cursor.moveToFirst()) while (cursor.moveToNext()){ str += cursor.getString(0)+" "; str += cursor.getString(1)+" "; str += cursor.getString(2)+"\n"; }; show.setText(str); } }
activity_register.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".Register"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/xm_zc" android:hint="输入姓名"/> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/xh_zc" android:hint="输入学号"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="确认注册" android:id="@+id/qd_zc"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="返回上一层" android:id="@+id/fh"/> <TextView android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/tv_show"/> </LinearLayout>
Manage.class(管理界面)
package com.example.myapp; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.app.AppCompatActivity; import android.content.ContentValues; import android.content.DialogInterface; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.Button; import android.widget.ListView; import android.widget.SimpleCursorAdapter; public class Manage extends AppCompatActivity { ListView listView; Button btn; DbHelper dbHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_manage); AlertDialog.Builder builder = new AlertDialog.Builder(Manage.this); dbHelper = new DbHelper(Manage.this,"MyDataBase,",3); listView=findViewById(R.id.list); dbHelper.getWritableDatabase(); renderListView(); btn=findViewById(R.id.new_list); btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent=new Intent(Manage.this,NewStudent.class); startActivityForResult(intent,1); } }); listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long idi) { Cursor cursor = dbHelper.queryAll("Student"); cursor.move(position+1); String id = cursor.getString(cursor.getColumnIndex("_id")); String xm = cursor.getString(cursor.getColumnIndex("xm")); String xh = cursor.getString(cursor.getColumnIndex("xh")); String bj = cursor.getString(cursor.getColumnIndex("bj")); String zy = cursor.getString(cursor.getColumnIndex("zy")); String cj = cursor.getString(cursor.getColumnIndex("cj")); Intent intent = new Intent(Manage.this,NewStudent.class); intent.putExtra("id",id); intent.putExtra("xm",xm); intent.putExtra("xh",xh); intent.putExtra("bj",bj); intent.putExtra("zy",zy); intent.putExtra("cj",cj); startActivityForResult(intent,2); } }); listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() { @Override public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long idi) { Cursor cursor = dbHelper.queryAll("Student"); cursor.move(position+1); String id = cursor.getString(cursor.getColumnIndex("_id"));//getColumnIndex("_id")得到这一列 String xm = cursor.getString(cursor.getColumnIndex("xm")); builder.setTitle("删除确认").setMessage("是否确认删除学生"+xm); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dbHelper.delStudent(id); renderListView(); } }); builder.show(); return true; } }); } private void renderListView() { Cursor cursor = dbHelper.queryAll("Student"); String from[] = new String[]{"_id", "xm", "xh","bj","zy","cj"}; int to[] = new int[]{R.id.id,R.id.xm, R.id.xh, R.id.bj, R.id.zy, R.id.cj}; SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.listview, cursor, from, to, 0); ListView listView = findViewById(R.id.list); listView.setAdapter(adapter); } @Override protected void onActivityResult(int reqCode,int resultCode,Intent intent){ super.onActivityResult(reqCode,resultCode,intent); if (resultCode==RESULT_OK){ String xm = intent.getStringExtra("xm"); String xh = intent.getStringExtra("xh"); String bj = intent.getStringExtra("bj"); String zy = intent.getStringExtra("zy"); String cj = intent.getStringExtra("cj"); dbHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("xm",xm); values.put("xh",xh); values.put("bj",bj); values.put("zy",zy); values.put("cj",cj); if (reqCode==1) dbHelper.insert("Student",values); else if (reqCode==2){ String id = intent.getStringExtra("id"); dbHelper.updateStudent(id,values); } renderListView(); } } }
activity_manage.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".Manage"> <ListView android:id="@+id/list" android:layout_width="match_parent" android:layout_height="wrap_content" /> <Button android:id="@+id/new_list" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="添加新学生" /> </LinearLayout>
对应的listview的布局文件,listview.xml
因为使用的是数据库来储存信息和调用,并没有重写对于listview的Adapter,而是使用Android自带的SimpleCursorAdapter类方法,用游标来储存,查看数据
<?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"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <TextView android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" android:text="id"/> <TextView android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" android:text="姓名" /> <TextView android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" android:text="学号" /> <TextView android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" android:text="班级" /> <TextView android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" android:text="专业" /> <TextView android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" android:text="成绩" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <TextView android:id="@+id/id" android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" /> <TextView android:id="@+id/xm" android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" /> <TextView android:id="@+id/xh" android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" /> <TextView android:id="@+id/bj" android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" /> <TextView android:id="@+id/zy" android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" /> <TextView android:id="@+id/cj" android:layout_width="0dp" android:layout_height="50dp" android:layout_weight="1" /> </LinearLayout> </LinearLayout>
对于新添加学生操作,使用NewStudent.class来完成
package com.example.myapp; import androidx.appcompat.app.AppCompatActivity; import android.content.Intent; import android.os.Bundle; import android.text.TextUtils; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class NewStudent extends AppCompatActivity { DbHelper dbHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_new_student); dbHelper=new DbHelper(NewStudent.this,"MyDataBase",3); Intent priIntent = getIntent(); EditText et_xm = findViewById(R.id.et_xm); EditText et_xh = findViewById(R.id.et_xh); EditText et_bj = findViewById(R.id.et_bj); EditText et_zy = findViewById(R.id.et_zy); EditText et_cj = findViewById(R.id.et_cj); String priId = priIntent.getStringExtra("id"); String prixm = priIntent.getStringExtra("xm"); String prixh = priIntent.getStringExtra("xh"); String pribj = priIntent.getStringExtra("bj"); String prizy = priIntent.getStringExtra("zy"); String pricj = priIntent.getStringExtra("cj"); et_xm.setText(prixm); et_xh.setText(prixh); et_bj.setText(pribj); et_zy.setText(prizy); et_cj.setText(pricj); Button btn_confirm = findViewById(R.id.btn_confirm); btn_confirm.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { EditText et_xm = findViewById(R.id.et_xm); EditText et_xh = findViewById(R.id.et_xh); EditText et_bj = findViewById(R.id.et_bj); EditText et_zy = findViewById(R.id.et_zy); EditText et_cj = findViewById(R.id.et_cj); String xm = et_xm.getText().toString(); String xh = et_xh.getText().toString(); String bj = et_bj.getText().toString(); String zy = et_zy.getText().toString(); String cj = et_cj.getText().toString(); if (TextUtils.isEmpty(xm)||TextUtils.isEmpty(xh)){ Toast.makeText(NewStudent.this,"学号或者姓名不可为空",Toast.LENGTH_SHORT).show(); return; } Intent intent = new Intent(); intent.putExtra("_id",priId); intent.putExtra("xm",xm); intent.putExtra("xh",xh); intent.putExtra("bj",bj); intent.putExtra("zy",zy); intent.putExtra("cj",cj); setResult(RESULT_OK,intent); finish(); } }); } }
activity_new_student.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:orientation="vertical" android:layout_height="match_parent" tools:context=".NewStudent"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_xm" android:hint="请输入姓名" /> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_xh" android:hint="请输入学号" /> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_bj" android:hint="请输入班级" /> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_zy" android:hint="请输入专业" /> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_cj" android:hint="请输入成绩" /> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/btn_confirm" android:text="确定" /> </LinearLayout>
运行效果图:
登录页面:
注册界面:
管理界面:
对listview进行操作:单击
长按
对listview的添加:
加载全部内容