增加数据库类，尝试使用数据库

app/src/main/java/hunnu/sj/raise_money/DataBase/DataBase.java

@@ -0,0 +1,28 @@
+package hunnu.sj.raise_money.DataBase;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+
+public class DataBase {
+    private static String driver = "com.mysql.jdbc.Driver";// MySQL驱动
+    private static String url = "jdbc:mysql://localhost:3306/dogson";//MYSQL数据库连接Url
+    private static String user = "root";//用户名
+    private static String password = "";/* 密码 */
+
+    //连接数据库
+
+    public static Connection getConn(){
+        Connection conn = null;
+        try {
+            Class.forName(driver);//获取MYSQL驱动
+            conn = DriverManager.getConnection(url, user, password);//获取连接
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+        return conn;
+    }
+
+}

app/src/main/java/hunnu/sj/raise_money/RegiteActivity.java

@@ -3,6 +3,11 @@ package hunnu.sj.raise_money;
 import androidx.appcompat.app.AppCompatActivity;
 
 import android.os.Bundle;
+import android.view.View;
+
+import java.sql.Connection;
+
+import hunnu.sj.raise_money.DataBase.DataBase;
 
 public class RegiteActivity extends AppCompatActivity {
 
@@ -11,4 +16,9 @@ public class RegiteActivity extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_registe);
     }
+
+    protected void onRegiste(View view){
+        Connection conn = DataBase.getConn();
+
+    }
 }

app/src/main/java/hunnu/sj/raise_money/SignInActivity.java

@@ -9,6 +9,12 @@ import android.view.View;
 import android.widget.EditText;
 
 import java.io.Serializable;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import hunnu.sj.raise_money.DataBase.DataBase;
 
 public class SignInActivity extends AppCompatActivity {
     public static final String IS_SIGNIN = "is.user.sign.in";
@@ -23,20 +29,49 @@ public class SignInActivity extends AppCompatActivity {
         EditText pswd = findViewById(R.id.pass_word);
         String name = usnm.getText().toString();
         String pasd = pswd.getText().toString();
-        if(!name.equals("admin")){
+        String sql = "select * from User";
+        Connection conn = DataBase.getConn();
+        try {
+            if(conn!=null){
+               PreparedStatement ps = conn.prepareStatement(sql);
+               if(ps!=null){
+                   ResultSet rs = ps.executeQuery();
+                   if(rs!=null&&rs.next()){
+                       User user = new User();
+                       user.setName(rs.getString("username"));
+                       user.setPasd(rs.getString("password"));
+                       user.setRole(rs.getString("role"));
+                       conn.commit();
+                       conn.close();
+                       Bundle bundle = new Bundle();
+                       bundle.putSerializable("user",user);
+                       Intent intent =new Intent(this,MainActivity.class);
+                       intent.putExtras(bundle);
+                       startActivity(intent);
+                   }
+               }
+            }
+        }catch (SQLException e){
+            e.printStackTrace();
+        }
+
+
+        /*if(!name.equals("admin")){
             usnm.setError("用户名错误");
         }else if(!pasd.equals("admin")){
             pswd.setError("密码错误");
         }else{
             User user = new User();
             user.setName(name);
-            user.setPasd(pasd);
+           user.setPasd(pasd);
             Bundle bundle = new Bundle();
-            bundle.putSerializable("user",user);
+           /* bundle.putSerializable("user",user);
             Intent intent =new Intent(this,MainActivity.class);
             intent.putExtras(bundle);
-            startActivity(intent);
-        }
-
+            startActivity(intent);*/
+    }
+    public void onToRegister(View view){
+        Intent intent = new Intent(this,RegiteActivity.class);
+        startActivity(intent);
     }
 }

app/src/main/res/layout/activity_registe.xml

@@ -7,7 +7,7 @@
     tools:context=".RegiteActivity">
 
     <EditText
-        android:id="@+id/editText2"
+        android:id="@+id/user_name"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:ems="10"
@@ -21,7 +21,7 @@
         app:layout_constraintVertical_bias="0.148" />
 
     <EditText
-        android:id="@+id/editText3"
+        android:id="@+id/pass_word"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:ems="10"
@@ -29,13 +29,13 @@
         android:inputType="textPassword"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintHorizontal_bias="0.373"
+        app:layout_constraintHorizontal_bias="0.358"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintVertical_bias="0.266" />
+        app:layout_constraintVertical_bias="0.256" />
 
     <EditText
-        android:id="@+id/editText4"
+        android:id="@+id/repass_word"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:ems="10"
@@ -48,29 +48,52 @@
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintVertical_bias="0.362" />
 
-    <EditText
-        android:id="@+id/editText5"
-        android:layout_width="263dp"
-        android:layout_height="47dp"
-        android:ems="10"
-        android:hint="用户角色（贫困学生/爱心人士）"
-        android:inputType="textPersonName"
+    <Button
+        android:id="@+id/registe"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="注册"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintHorizontal_bias="0.479"
+        app:layout_constraintHorizontal_bias="0.427"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintVertical_bias="0.461" />
+        app:layout_constraintVertical_bias="0.765" />
 
-    <Button
-        android:id="@+id/registe"
+    <RadioGroup
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="注册"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintHorizontal_bias="0.229"
+        app:layout_constraintHorizontal_bias="0.63"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.56">
+
+        <RadioButton
+            android:id="@+id/ratio1"
+            android:layout_width="168dp"
+            android:layout_height="wrap_content"
+            android:text="爱心人士" />
+
+        <RadioButton
+            android:id="@+id/radio2"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="贫困学生" />
+    </RadioGroup>
+
+    <TextView
+        android:id="@+id/textView3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="您是"
+        android:textColor="@android:color/background_dark"
+        android:textSize="30sp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.202"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintVertical_bias="0.612" />
+        app:layout_constraintVertical_bias="0.557" />
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/layout/activity_signin.xml

@@ -44,6 +44,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
+        android:onClick="onToRegister"
         android:text="注册"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"