android - 如何在 mainactivity 中定义 dbhandler 构造函数变量？

Question

dbhandler 类

public class DBHandler extends SQLiteOpenHelper{

private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "feedbackDB.db";
private static final String TABLE_FEEDBACK = "feedback";
private static final String DB_PATH = "/data/data/com.example.vbfeed/databases/";

public DBHandler(Context context, String name,CursorFactory factory, int version) {
        super(context,context.getExternalFilesDir(null).getAbsolutePath() + DB_PATH + DATABASE_NAME, factory, DATABASE_VERSION);

    }

Click上的主要活动代码onCreate和按钮

DBHandler dbHandler = new DBHandler(getBaseContext(),name,null, 1);
//having error in this line--just constructor defining error,
//i dono the variables to declare

Answer 1

将您的构造函数更改为

  public DBHandler(Context context) { 
  super(context, DATABASE_NAME, null, DATABASE_VERSION);
  } 

并使用

  DBHandler db = new DBHnadler(this);

http://www.vogella.com/articles/AndroidSQLite/article.html

http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html

检查上面的链接以供参考。