学习源码《随手记》知识总结

来源：互联网发布：python小游戏代码编辑：程序博客网时间：2024/05/20 14:40

1：这个APP，主要是一个记录每天收入与支出账目的应用

2：应用到的知识点

1：Android SQLlite 数据库相关知识

如果应用中需要多了表，可以统一定义一个类，将各个表的相关信息一起写出来

          主要代码:
public class MyDbInfo {

   private static String TableNames[] = {
       "TBL_EXPENDITURE_CATEGORY",
       "TBL_EXPENDITURE_SUB_CATEGORY",
       "TBL_INCOME_CATEGORY",
       "TBL_INCOME_SUB_CATEGORY",
       "TBL_ACCOUNT_TYPE",
       "TBL_ACCOUNT_SUB_TYPE",
       "TBL_ACCOUNT",
       "TBL_STORE",
       "TBL_ITEM",
       "TBL_EXPENDITURE",
       "TBL_INCOME",
       "TBL_TRANSFER"
   };//表名

   private static String FieldNames[][] = {
           {"ID","NAME","BUDGET"},
           {"ID","NAME","PARENT_CATEGORY_ID"},
           {"ID","NAME"},
           {"ID","NAME","PARENT_CATEGORY_ID"},
           {"ID","NAME","POSTIVE"},
           {"ID","NAME","PARENT_TYPE_ID"},
           {"ID","NAME","TYPE_ID","SUB_TYPE_ID","ACCOUNT_BALANCE"},
           {"ID","NAME"},
           {"ID","NAME"},
           {"ID", "AMOUNT", "EXPENDITURE_CATEGORY_ID", "EXPENDITURE_SUB_CATEGORY_ID", "ACCOUNT_ID", "STORE_ID", "ITEM_ID", "DATE", "MEMO"},
           {"ID", "AMOUNT", "INCOME_CATEGORY_ID", "INCOME_SUB_CATEGORY_ID", "ACCOUNT_ID", "ITEM_ID", "DATE", "MEMO"},
           {"ID", "AMOUNT", "ACCOUNT_ID", "ITEM_ID", "DATE", "MEMO"}


   };//字段名
   private static String FieldTypes[][] = {
           {"INTEGER PRIMARY KEY AUTOINCREMENT","text","DOUBLE"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT","INTEGER"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT","INTEGER"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT","INTEGER","DOUBLE"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT","INTEGER"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT","INTEGER","INTEGER","DOUBLE"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","TEXT"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","DOUBLE","INTEGER","INTEGER","INTEGER","INTEGER","INTEGER","TEXT","TEXT"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","DOUBLE","INTEGER","INTEGER","INTEGER","INTEGER","TEXT","TEXT"},
           {"INTEGER PRIMARY KEY AUTOINCREMENT","DOUBLE","INTEGER","INTEGER","TEXT","TEXT"}
   };//字段类型

   public MyDbInfo() {
       // TODO Auto-generated constructor stub
   }

   public static String[] getTableNames() {
       return TableNames;
   }

   public static String[][] getFieldNames() {
       return FieldNames;
   }

   public static String[][] getFieldTypes() {
       return FieldTypes;
   }

(java 二维数组，扩展 n维数组。。。)

DBHelper中

      @Override
           public void onCreate(SQLiteDatabase db)
           {
                if (TableNames == null)
                {
                   message = NO_CREATE_TABLES;
                   return;
                }
                for (int i = 0; i < TableNames.length; i++)
                {
                   String sql = "CREATE TABLE " + TableNames[i] + " (";
                   for (int j = 0; j < FieldNames[i].length; j++)
                   {
                       sql += FieldNames[i][j] + " " + FieldTypes[i][j] + ",";
                   }
                   sql = sql.substring(0, sql.length() - 1);
                   sql += ")";
                   db.execSQL(sql);
                }
           }

2：xml 布局，主要是FrameLayout的使用以及style的使用

如果多个控件或者viewgroup 具有相同的属性那么可以将这些属性统一写成一个style 一方面避免多次书写另一方面使代码简洁了，如果某一控件具有一个独特的属性，那么可以定义一个style 继承统一的style 并书写其独特的属性

统一的style

独特的属性

（java 父类与子类的关系 -->继承）

3：计算当天处于那个周，主要是Calendar的使用

4：通过Thread更新UI 作出动态的效果