Android——一个简单的银行系统

采用SQLite数据库进行对数据进行读取和插入

实现功能：
1：注册用户信息
2：登录界面
3：存钱，取钱，查询余额

第一步：先创建一个实体类User
除了对字段进行set和get还多了Deposit（）Withdraw两个方法，用于在后面FUNCTION界面进行存钱和取钱
代码如下：
public class User {
private String BankName;
private String Name;
private int Money;
private String PassWord;
public User(String Name, String Password, String BankName , int Money) {
super();
this.Name = Name;
this.PassWord = Password;
this.BankName = BankName;
this.Money = Money;
}
public User(){
}
public void setMoney(int Money){
this.Money = Money;
}
public String getName() {
return Name;
}
public String getPassWord() {
return PassWord;
}
public String getBankName() {
return BankName;
}
public int getMoney() {
return Money;
}
//存钱
public void Deposit(int Money) {
this.Money += Money;
}
//取钱
public void Withdraw(int Money) {
if (this.Money < Money) {
Log.d(Dao.TAG, “Withdraw: 余额不足!”);
return;
} else {
this.Money -= Money;
}
}
public String toString() {
return “[户主:”+Name+" 银行类型："+BankName+" 余额："+Money+"]";
}
}
第二步：
建立一个MyHelper类用于继承SQLiteOpenHelper类，用于创建数据库
代码如下：
public class MyHelper extends SQLiteOpenHelper {
public static final String TableName = “BankSystem”;
public static final String Name = “Name”;
public static final String PassWord = “PassWord”;
public static final String BankType = “BankType”;
public static final String Money = “Money”;
private static final String DataBase = “BankSystem.db”;
private static final SQLiteDatabase.CursorFactory Factory = null;
public static final int version = 1;
public MyHelper(@Nullable Context context) {
super(context, DataBase, Factory, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
String sql = “create table " + TableName + “( “+Name+” varchar(20) primary key, “+PassWord+” varchar(20),”+BankType+” varchar(20) ,"+Money+" Interget);";
db.execSQL(sql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists "+TableName);
onCreate(db);
}
}
第三步：
建立登录界面也就是启动项MainActivity
Drawable 类是对登录界面的两个图片进行合适的缩放
MainActivity.java代码如下：
public class MainActivity extends AppCompatActivity {
private static EditText editTextUserName;
private static EditText editTextUserPassWord;
private Button btn_Login,btn_Register;
private TextView TitleImage;
public static String name =null;
public static String password = null;
static int i = 0;
private MyHelper myhelper = null ;
private SQLiteDatabase DB;
Dao dao = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

    myhelper = new MyHelper(MainActivity.this);

    editTextUserName = (EditText) findViewById(R.id.userName);
    editTextUserPassWord = (EditText) findViewById(R.id.userPassword);
    btn_Login = (Button) findViewById(R.id.Login);
    btn_Register = (Button) findViewById(R.id.Register);
    TitleImage = (TextView)findViewById(R.id.titleImage);

    Drawable drawableUserName = getResources().getDrawable(R.drawable.user);
    //第一个0是距左边距离，第二个0是距上边距离，40分别是长宽
    drawableUserName.setBounds(0, 0, 90, 90);
    editTextUserName.setCompoundDrawables(drawableUserName, null, null, null);
    //****************************
    Drawable drawableUserPassWord = getResources().getDrawable(R.drawable.unlock);
    drawableUserPassWord.setBounds(0, 0, 90, 90);
    editTextUserPassWord.setCompoundDrawables(drawableUserPassWord, null, null, null);
    //****************************
    Drawable drawableTitleImage= getResources().getDrawable(R.drawable.bastard);
    drawableTitleImage.setBounds(0, 0, 100, 90);
    TitleImage.setCompoundDrawables(drawableTitleImage, null, drawableTitleImage, null);
    OnClick onClick = new OnClick();
    btn_Login.setOnClickListener(onClick);
    btn_Register.setOnClickListener(onClick);
}

// public boolean checkAccount(String Name){
// DB=myhelper.getReadableDatabase();
// String query="select * from BankSystem where Name=? ";
// Cursor cursor=DB.rawQuery(query, new String[]{Name});
// if(cursor.moveToNext()){
// cursor.close();
// return true;
// }
// cursor.close();
// return false;
// }

class OnClick implements View.OnClickListener{
@Override
public void onClick(View v) {
Intent intent = null;
dao = new Dao(MainActivity.this);

        name = editTextUserName.getText().toString().trim();
        password = editTextUserPassWord.getText().toString().trim();
        switch (v.getId())
        {
            case R.id.Login:
                if (dao.login(name,password) == true) {
                   Toast.makeText(MainActivity.this,"LOGIN Success",Toast.LENGTH_SHORT).show();
                    intent = new Intent(MainActivity.this, Function.class);
                    break;
                }
                else
                {
                    Toast.makeText(MainActivity.this,"LOGIN Fail",Toast.LENGTH_SHORT).show();
                    break;
                }
            case R.id.Register:
                intent = new Intent(MainActivity.this,Register.class);
                break;
        }
        startActivity(intent);
    }
}

}
activity_main.xml文件如下
效果图如下：
前者是对图片进行了Drawable处理，后面是没有进行处理

代码如下：

<EditText
   android:id="@+id/userName"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:hint=" Please Entry your BankUserName:"
   android:drawableLeft="@drawable/user"
   android:layout_marginTop="30dp"/>
<EditText
        android:id="@+id/userPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint=" Please Entry your BankUserPassword:"
        android:drawableLeft="@drawable/unlock"
        android:layout_below="@id/userName"
        android:layout_marginTop="20dp"
        android:inputType="textPassword"/>
<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">
<Button
 android:id="@+id/Login"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:text="Login"
 android:textAllCaps="false"
 android:layout_marginTop="160dp"
 android:layout_weight="1"/>
<Button
        android:id="@+id/Register"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Register"
        android:textAllCaps="false"
        android:layout_marginTop="160dp"
        android:layout_weight="1"/>
</LinearLayout>

第四步建立一个注册的avtivity命名为Register Register.java代码如下： public class Register extends AppCompatActivity { private EditText editTextName,editTextPassWord,editTextEntryPassWord,FirstDeposit,editBankType; private Button btn_Submit; private Spinner spinner; public static String Name = null; public static String PassWord = null; public static String EntryPassWord = null; public static String BankType = null; public static int Money =0; Dao dao =null;

@Override
protected void onCreate(final Bundle savedInstanceState)  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);
    editTextName = (EditText) findViewById(R.id.RegisterBankUserName);
    editTextPassWord = (EditText) findViewById(R.id.RegisterBankPassWord);
    editTextEntryPassWord = (EditText) findViewById(R.id.AgainRegisterBankPassWord);
    FirstDeposit = (EditText) findViewById(R.id.InitDeposit);
    spinner = (Spinner) findViewById(R.id.spinner_BankType);
    btn_Submit = (Button) findViewById(R.id.RegisterSubmitButton);
    
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            String [] str = getResources().getStringArray(R.array.spinner);
            //点击的事项，选择的开户银行
            BankType = str[position];
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });
        btn_Submit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dao = new Dao(Register.this);
                Name = editTextName.getText().toString().trim();
                PassWord = editTextPassWord.getText().toString().trim();
                EntryPassWord = editTextEntryPassWord.getText().toString().trim();
                BankType = spinner.getContext().toString().trim();
                try {
                    Money = Integer.parseInt(FirstDeposit.getText().toString().trim());
                }catch (NumberFormatException e)
                {
                    e.printStackTrace();
                }
                if ("".equals(Name) && "".equals(PassWord) && "".equals(EntryPassWord) && "".equals(BankType))
                {
                    Toast.makeText(Register.this,"信息不能为空，请重试",Toast.LENGTH_SHORT).show();
                    return;
                }
                if (! PassWord.equals(EntryPassWord))
                {
                    Toast.makeText(Register.this,"密码不一致，请重试",Toast.LENGTH_SHORT).show();
                    return;
                }
                else if ( Money  < 10)
                {
                    Toast.makeText(Register.this,"首次开户金额不能小于10元，请重试",Toast.LENGTH_SHORT).show();
                    return;
                }
                    dao.Insert(new User(Name,PassWord,BankType,Money));
                    Log.d(Dao.TAG,"success");
                    Intent intent = new Intent(Register.this, Function.class);
                    startActivity(intent);
            }
        });
    }
}
activity_register.xml文件如下：
activity_register.xml效果图如下：

activity_register.xml代码如下：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="20dp">
<TextView
        android:id="@+id/Title"
        android:layout_width="400dp"
        android:layout_height="30dp"
        android:text="Registration information form"
        android:layout_marginLeft="87dp"
        android:textSize="20sp"
        android:textColor="#000" />
<EditText
        android:id="@+id/RegisterBankUserName"
        android:hint="Please input your name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_below="@id/Title"/>
<TextView
        android:id="@+id/Sex"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Please choice your sex:"
        android:layout_below="@id/RegisterBankUserName"
        android:layout_marginTop="15dp"/>
<RadioGroup
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    <RadioButton
            android:id="@+id/sexRadioButtonMale"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Male"
            android:layout_marginTop="95dp"
            android:layout_marginLeft="155dp"/>
    <RadioButton
            android:id="@+id/sexRadioButtonFemale"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Female"
            android:layout_marginTop="-31dp"
            android:layout_marginLeft="230dp"/>

</RadioGroup>
<EditText
        android:id="@+id/Age"
        android:hint="Please input your age"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_below="@id/Sex"/>
<EditText
        android:id="@+id/PhoneNumber"
        android:hint="Please input your PhoneNumber"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_below="@id/Age"/>

<EditText
        android:id="@+id/RegisterBankPassWord"
        android:hint="Please input your PassWord"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="5dp"
        android:layout_below="@id/PhoneNumber"/>
<EditText
        android:id="@+id/AgainRegisterBankPassWord"
        android:hint="Please again entry your PassWord"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_below="@id/RegisterBankPassWord"/>
<TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:text="Please choose your bank type："
        android:layout_below="@id/AgainRegisterBankPassWord"/>
<EditText
        android:id="@+id/InitDeposit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Please input the amount you want to deposit:"
        android:layout_below="@id/title"
        android:textSize="15sp"
        android:layout_marginTop="10dp"/>
<Spinner
        android:id="@+id/spinner_BankType"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:entries="@array/spinner"
        android:layout_gravity="center"
        android:layout_marginTop="347dp"
        android:layout_marginRight="110dp"
        android:layout_alignRight="@id/InitDeposit"/>
<Button
        android:id="@+id/RegisterSubmitButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Submit"
        android:layout_below="@id/spinner_BankType"
        android:layout_marginTop="100dp"
        android:textAllCaps="false"
        android:textSize="20sp" />

第五步：建立一个Function活动，用于存钱，取钱，查询三个功能 Function.java代码如下： public class Function extends AppCompatActivity { private Button btn_saveMoney,btn_withdrawMoney,btn_search; Dao dao = new Dao(); User user = null; public static int FUNC_Money = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.function);
    btn_saveMoney = (Button) findViewById(R.id.SaveMoney);
    btn_withdrawMoney = (Button) findViewById(R.id.WithdrawMoney);
    btn_search = (Button) findViewById(R.id.Search);
    OnClick onClick = new OnClick();
    btn_saveMoney.setOnClickListener(onClick);
    btn_withdrawMoney.setOnClickListener(onClick);
    btn_search.setOnClickListener(onClick);
}
class OnClick implements View.OnClickListener
{

    @Override
    public void onClick(View v) {
        String Name = Register.Name;
        String Password = Register.PassWord;
        String BankType = Register.BankType;
        int Money = Register.Money;
        user = new User(Name,Password,BankType,Money);
        switch (v.getId()){
            case R.id.SaveMoney:
                AlertDialog.Builder dialogSaveMoney = new AlertDialog.Builder(Function.this);
                View viewSaveMoney = LayoutInflater.from(Function.this).inflate(R.layout.activity_save_money,null);
                TextView textViewSaveMoney = viewSaveMoney.findViewById(R.id.SaveMoneyTextView);
                final EditText editTextSaveMoney = viewSaveMoney.findViewById(R.id.SaveMoneyEditText);
                Button submitSaveMoney = viewSaveMoney.findViewById(R.id.SaveMoneyButton);
                submitSaveMoney.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        try {
                            FUNC_Money = Integer.parseInt(editTextSaveMoney.getText().toString());
                        }catch (NumberFormatException e)
                        {
                            e.printStackTrace();
                        }
                        String Name = Register.Name;
                        int Money = dao.Query(Name);
                        user.setMoney(Money);
                        user.Deposit(FUNC_Money);
                        dao.Update(Name,user.getMoney());
                        Toast.makeText(Function.this,"当前账户余额为"+ user.getMoney(),Toast.LENGTH_SHORT).show();

                    }
                    public void onClick(DialogInterface dialog, int which, boolean isChecked){
                        dialog.dismiss();
                    }
                });
                dialogSaveMoney.setTitle("Little Bastard Bank").setIcon(R.drawable.bastard).setView(viewSaveMoney).show();
                break;
            case R.id.WithdrawMoney:
                AlertDialog.Builder dialogWithdraw = new AlertDialog.Builder(Function.this);
                View viewWithdrawMoney = LayoutInflater.from(Function.this).inflate(R.layout.activity_withdraw_money,null);
                TextView textViewWithdrawMoney = viewWithdrawMoney.findViewById(R.id.WithdrawMoneyTextView);
                final EditText editTextWithdrawMoney = viewWithdrawMoney.findViewById(R.id.WithdrawMoneyEditText);
                Button buttonWithdrawMoney = viewWithdrawMoney.findViewById(R.id.WithdrawMoneyButton);
                buttonWithdrawMoney.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        try {
                            FUNC_Money = Integer.parseInt(editTextWithdrawMoney.getText().toString());
                        }catch (NumberFormatException e)
                        {
                            e.printStackTrace();
                        }
                        String Name = Register.Name;
                        int Money = dao.Query(Name);
                        user.setMoney(Money);
                        user.Withdraw(FUNC_Money);
                        dao.Update(Name,user.getMoney());
                        Toast.makeText(Function.this,"当前账户余额为"+ user.getMoney(),Toast.LENGTH_SHORT).show();

                    }
                    public void onClick(DialogInterface dialog, int which, boolean isChecked){
                        dialog.dismiss();
                    }
                });
                dialogWithdraw.setTitle("Little Bastard Bank").setIcon(R.drawable.bastard).setView(viewWithdrawMoney).show();
                break;
            case R.id.Search:
                AlertDialog.Builder dialogSearch = new AlertDialog.Builder(Function.this);
                View viewSearch = LayoutInflater.from(Function.this).inflate(R.layout.activity_search,null);
                TextView textViewSearch = viewSearch.findViewById(R.id.SearchTextView);
                final TextView textViewSearchHint = viewSearch.findViewById(R.id.SearchTextViewHint);
                Button buttonSearch = viewSearch.findViewById(R.id.SearchButton);
                buttonSearch.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        String Name = Register.Name;
                        int EXE_Money = dao.Query(Name);
                        Toast.makeText(Function.this,"当前账户余额为"+ EXE_Money,Toast.LENGTH_SHORT).show();
                    }
                });
                dialogSearch.setTitle("Little Bastard Bank").setIcon(R.drawable.bastard).setView(viewSearch).show();
                break;
        }
    }
}

}
activity_function.xml文件如下
activity_function.xml效果图如下：

activity_function.xml代码如下：

/*********************************************运行效果图演示***************************************/
首先得注册才能登录，或者使用数据库中的用户信息登录都可以
![在这里插入图片描述](https://img-blog.csdnimg.cn/20210205160847366.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L05ld3M1MzIzMTMyMw==,size_16,color_FFFFFF,t_70#pic_center)

注册界面，未填写信息前

填写完信息之后

点击submit按钮跳转到Function界面

随意点一个然后进行操作
我们先点存钱，界面如下：

在我们注册用户时存入的金额是10元（开户最少存入金额10元），在这里我们存1块进去，底部会用Toast显示11块
//注意看底部Toast
//注意看底部Toast
//注意看底部Toast

然后我们点击取钱，界面如下:

由于之前存入一块，我们的账户现在剩余11元，然后在取出2元，账户剩余9元
//注意看底部Toast
//注意看底部Toast
//注意看底部Toast

然后点击查询按钮，会显示9元
//注意看底部Toast
//注意看底部Toast
//注意看底部Toast

记得在values中建立文件用于Spinner下拉列表中可供选择的值，不然就会出现上面那个错误，找不到选择的值