数据库教程:安卓小项目，课程设计，课设，刷题app

一、需求分析：

如今考驾照已经成为了很多人的刚需，对于科目1与科目4来说，大量的刷题必不可少。
根据市场需求，我们开发了一个可以在手机刷题的app方便人们随时随地地刷题。

二、部分代码

public class Main3Activity extends AppCompatActivity {     private Sql sql;     int jub = 1;     String ans=null;     String anal=null;     String type=null;     int id;     String topic;     String a;     String b;     String c;     String d;     String img;     boolean boo=true;     @Override     protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main3);         Intent getI = getIntent();         final Bundle data = getI.getExtras();         type= data.getString("data");          replace(jub);          Button btnUp = findViewById(R.id.btnUp);  //上一题按钮         btnUp.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 if (jub>=2){                     jub--;                     replace(jub);                 }              }         });          Button btnDown = findViewById(R.id.btnDown);  //下一题按钮         btnDown.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 jub++;                 replace(jub);                 RadioGroup radioGroup2 = findViewById(R.id.radioGroup2);                 radioGroup2.check(-1);             }         });          Button btnCol = findViewById(R.id.btnCol);         if(!type.equals("col")){           btnCol.setText("加入错题");         }else {            btnCol.setText("删除");             //btnCol.setText(type);         }         btnCol.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 if(!type.equals("col")){                     SQLiteDatabase db = sql.getWritableDatabase();                     Cursor cursor = db.query(true, "col",null,"id = "+id,null,null,null,null,null);                     if (cursor.getCount()==1){                         Toast toast=Toast.makeText(getApplicationContext(), "已经加入", Toast.LENGTH_SHORT);                         toast.show();                     }else {                         int num;                         Cursor cur = db.rawQuery("select * from col", null);                         num=cur.getCount();                         if(cur.moveToFirst()){                             int frist=cur.getInt(cur.getColumnIndex("id"));                             if (frist!=1){                                 num=num+frist;                             }else {                                 num++;                             }                         }                         if (num==0)num++;                         ContentValues contentValues = new ContentValues();                         contentValues.put("id",num);                         contentValues.put("type",type);                         contentValues.put("topic",topic);                         contentValues.put("a",a);                         contentValues.put("b",b);                         contentValues.put("c",c);                         contentValues.put("d",d);                         contentValues.put("answer",ans);                         contentValues.put("analyse",anal);                         contentValues.put("img",img);                         db.insert("col",null,contentValues);                         Toast toast=Toast.makeText(getApplicationContext(), "加入成功", Toast.LENGTH_SHORT);                         toast.show();                     }                 }else {                 SQLiteDatabase db = sql.getWritableDatabase();                 Cursor cursor = db.query(true, type,null,"id = "+id,null,null,null,null,null);                      if (cursor.getCount()==1){                          db.delete("col","id=?",new String[]{String.valueOf(id)});                          Toast toast=Toast.makeText(getApplicationContext(), "删除成功", Toast.LENGTH_SHORT);                          toast.show();                       }else {                          Toast toast=Toast.makeText(getApplicationContext(), "已经删除", Toast.LENGTH_SHORT);                          toast.show();                      }                   }             }         }); 

三、相关截图

源码请+q:2538966470

数据库技术:安卓小项目，课程设计，课设，刷题app地址：https://blog.csdn.net/weixin_45702159/article/details/107877828

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