Android-每日打卡APP-实现登录功能
每日打卡APP新的进展-实现登录功能-昨天已经把注册功能实现了，今天也很快把登录功能做了出来，然后接着着手做其他功能，打卡功能写在下一篇博客
能够实现登录和注册，注册相关的代码我在之前的博客中写过了，这里主要是登录的部分！同时登录后自己的学号姓名信息会显示在自己的主页里！
我在CRUD.java中又添加了一个方法，用于查询注册后的学生的账户信息以便登录，这部分也是对应着SQLite中查询的部分
基本查询语句格式：SELECT * FROM table_name WHRER 条件表达式
先看效果，代码放后边
public Student getStudentById(String id){ SQLiteDatabase db = dbHelper.getReadableDatabase(); String selectQuery = "SELECT "+ Student.KEYWORD +","+ Student.ID +","+ Student.NAME +","+ Student.GRADE + ","+ Student.PHONE+ " FROM " + Student.TABLE +" WHERE " + Student.ID + "=?"; int count = 0; Student student = new Student(); Cursor cursor = db.rawQuery(selectQuery,new String[]{String.valueOf(id)}); if (cursor.moveToFirst()){ do { student.keyword = cursor.getInt(cursor.getColumnIndex(Student.KEYWORD)); student.id = cursor.getString(cursor.getColumnIndex(Student.ID)); student.name = cursor.getString(cursor.getColumnIndex(Student.NAME)); student.grade = cursor.getString(cursor.getColumnIndex(Student.GRADE)); student.phone = cursor.getString(cursor.getColumnIndex(Student.PHONE)); }while (cursor.moveToNext()); } cursor.close(); db.close(); return student; }
然后是实现登录的代码
package com.example.clockappliction; 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.TextView; import android.widget.Toast; import com.example.clockappliction.DataBase.CRUD; import com.example.clockappliction.Information.Student; public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button btn_login, btn_reg; private EditText et_log_id,et_log_name,et_log_grade,et_log_phone; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn_login = (Button) findViewById(R.id.btn_login); btn_login.setOnClickListener(this); btn_reg = (Button) findViewById(R.id.btn_reg); btn_reg.setOnClickListener(this); et_log_id = (EditText) findViewById(R.id.et_log_id); et_log_name = (EditText) findViewById(R.id.et_log_name); et_log_grade = (EditText) findViewById(R.id.et_log_grade); et_log_phone = (EditText) findViewById(R.id.et_log_phone); } @Override public void onClick(View view) { if (view == findViewById(R.id.btn_login)){ Student student = new Student(); CRUD crud = new CRUD(this); //获取输入框的学生信息 student.id = et_log_id.getText().toString(); student.name = et_log_name.getText().toString(); student.grade = et_log_grade.getText().toString(); student.phone = et_log_phone.getText().toString(); //通过id获取数据库学生信息 Student studentData =crud.getStudentById(student.id); //登录 if (student.id.equals(studentData.id)){ if (student.name.equals(studentData.name)){ if (student.grade.equals(studentData.grade)){ if (student.phone.equals(studentData.phone)){ Intent intent =new Intent(this,MenuActivity.class); intent.putExtra("st_id",student.id); intent.putExtra("st_name",student.name); startActivity(intent); }else { Toast.makeText(this, "电话号码不正确", Toast.LENGTH_SHORT).show(); } }else { Toast.makeText(this, "班级不正确", Toast.LENGTH_SHORT).show(); } }else { Toast.makeText(this, "姓名不正确", Toast.LENGTH_SHORT).show(); } }else { Toast.makeText(this, "学号不正确", Toast.LENGTH_SHORT).show(); } } else if (view == findViewById(R.id.btn_reg)) { //跳转到登录页面 Intent intent = new Intent(this,RegActivity.class); intent.putExtra("keys",0); startActivity(intent); } } }
xml文件
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout 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" android:background="#DDDDDD" tools:context=".MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/tv_title" android:text="每日打卡APP" android:textSize="30sp" android:layout_margin="45dp" android:layout_alignParentTop="true" android:layout_alignParentLeft="true" android:layout_alignParentRight="true" android:layout_alignParentStart="true" /> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_log_id" android:hint="学号" android:layout_below="@+id/tv_title" android:layout_marginTop="15dp" ></EditText> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_log_name" android:hint="姓名" android:layout_below="@+id/et_log_id" android:layout_marginTop="15dp" ></EditText> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_log_grade" android:hint="班级" android:layout_below="@+id/et_log_name" android:layout_marginTop="15dp" ></EditText> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et_log_phone" android:hint="手机号码" android:layout_below="@+id/et_log_grade" android:layout_marginTop="15dp" ></EditText> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/btn_login" android:text="登录" android:textSize="30dp" android:layout_below="@+id/et_log_phone" android:layout_marginTop="20dp" android:layout_marginLeft="20dp" ></Button> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/btn_reg" android:text="注册" android:textSize="30dp" android:layout_toRightOf="@+id/btn_login" android:layout_below="@+id/et_log_phone" android:layout_marginTop="20dp" android:layout_marginLeft="20dp" ></Button> </RelativeLayout>
MenuActivity.java
package com.example.clockappliction; import android.annotation.SuppressLint; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; import androidx.annotation.Nullable; import androidx.appcompat.app.AppCompatActivity; public class MenuActivity extends AppCompatActivity implements View.OnClickListener{ private TextView tv_my_id,tv_my_name; private Button btn_mu_dk; @SuppressLint("MissingInflatedId") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_menu); btn_mu_dk = (Button) findViewById(R.id.btn_mu_dk); btn_mu_dk.setOnClickListener(this); tv_my_id = (TextView) findViewById(R.id.tv_my_id); tv_my_name = (TextView) findViewById(R.id.tv_my_name); Intent intent = getIntent(); String st_id =intent.getStringExtra("st_id"); String st_name =intent.getStringExtra("st_name"); tv_my_id.setText("学号:"+ st_id); tv_my_name.setText("姓名:"+ st_name); } @Override public void onClick(View view) { if (view==findViewById(R.id.btn_mu_dk)){ Intent intent = new Intent(this,ClockActivity.class); String cid = tv_my_id.getText().toString(); intent.putExtra("cid",cid); startActivity(intent); } } }
