插入一个按钮，允许我删除Android上的所有SQLite表信息

遵循本教程

我也成功地从SQLite数据库中获取信息并显示在列表视图中

然而，我不知道如何制作一个按钮，在插入时删除这些信息，以及这些代码应该放在哪里

如果有人能帮忙，我将不胜感激

这是我的dboperations.java 公共类DbOperations扩展了SQLiteOpenHelper{

private static final int DB_VERSION = 1;
private static final String DB_NAME = "standing_info.db";
private static final String TABLE_NAME = "standing_table";
private static final String CREATE_QUERY = "create table "+StandingContract.StandingEntry.TABLE_NAME+
        "("+ StandingContract.StandingEntry.ID+ " text,"+ StandingContract.StandingEntry.WON+" text,"+
        StandingContract.StandingEntry.HALVED+ " text,"+ StandingContract.StandingEntry.LOST+" text,"+
        StandingContract.StandingEntry.POINTS+ " text);";

DbOperations(Context ctx) {

    super(ctx, DB_NAME, null, DB_VERSION);
    Log.d("Database operations", "Database created...");
}
@Override
public void onCreate(SQLiteDatabase db) {

    db.execSQL(CREATE_QUERY);

    Log.d("Database operations", "Table created...");

}

public void addInformations ( SQLiteDatabase db,String id,String won, String halved, String lost, String points){
    ContentValues contentValues = new ContentValues();
    contentValues.put(StandingContract.StandingEntry.ID,id);
    contentValues.put(StandingContract.StandingEntry.WON,won);
    contentValues.put(StandingContract.StandingEntry.HALVED,halved);
    contentValues.put(StandingContract.StandingEntry.LOST,lost);
    contentValues.put(StandingContract.StandingEntry.POINTS,points);
    db.insert(StandingContract.StandingEntry.TABLE_NAME, null, contentValues);
    Log.d("Database operations", "One Row Inserted...");

}

public Cursor getInformations(SQLiteDatabase db)
{

    String[] projections = {StandingContract.StandingEntry.ID, StandingContract.StandingEntry.WON,
    StandingContract.StandingEntry.HALVED, StandingContract.StandingEntry.LOST, StandingContract.StandingEntry.POINTS};
    Cursor cursor = db.query(StandingContract.StandingEntry.TABLE_NAME,projections,

            null,null,null,null,null,null);

    return cursor;
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

在你的主要活动中

DatabaseAdapter.DatabaseHelper db = new DatabaseAdapter.DatabaseHelper(getBaseContext());

button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
      db.deleteAll();
    }
});

在您的DatabaseAdapter中，它是您案例中的dboperations

public boolean deleteAll() {
            SQLiteDatabase db = this.getReadableDatabase();
            db.execSQL("DROP TABLE IF EXISTS " + TBL_TABLE1);
            db.execSQL("DROP TABLE IF EXISTS " + TBL_TABLE2);
            return true;
        }

---

请描述场景..而不是给出YouTube上的链接这里是我尝试删除的内容。setOnClickListener（new OnClickListener（）{@Override public void onClick（View v）{}public void DeleteDatabase（SQLiteDatabase db，String table）{db.execSQL（“如果存在DROP table”+“standing_table”）；db.close（）；}；我的主要问题是，如果我要添加一个按钮来删除我制作的sqlite表，我是否需要使用除按钮所在的xml和My MainActivity.java以外的任何东西。向我们展示您的尝试。共享您的代码。我是否需要创建一个除My MainActivity之外的新java类，以便在单击按钮时启动活动？您的activity应该扩展SQLiteOpenHelper并实现其方法。在dboperations.java中，使用我提供的代码。您可以从另一个活动调用此方法。您很可能是正确的，但我需要一个要点，一步一步地说明如何放置位置和放置内容…public void addStanding（View View View）{Intent i=new Intent（MainActivity.this，SaveInfo.class）；startActivity（i）；}公共无效显示列表（视图）{Intent i=newintent（MainActivity.this，displayStandings.class）；startActivity（i）；}

public class MainActivity extends AppCompatActivity {
Button Login, Register, Delete;
int status = 0;
/**
 * ATTENTION: This was auto-generated to implement the App Indexing API.
 * See https://g.co/AppIndexing/AndroidStudio for more information.
 */
 private GoogleApiClient client;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Login = (Button) findViewById(R.id.Login);
    Register = (Button) findViewById(R.id.Reg);
    Delete  = (Button) findViewById(R.id.buttondelete);


    Register.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {

     Intent i = new Intent(MainActivity.this,          RegisterActivity.class);
            startActivity(i);
        }
    });

    Delete.setOnClickListener(new OnClickListener() {
                                  @Override
                                  public void onClick(View v) {

                                  }

                                  public void DeleteDatabase(SQLiteDatabase db, String table) {


                                      db.execSQL("DROP TABLE IF EXISTS " + "standing_table");
                                      db.close();
                                  }