ArrayList & lt; HashMap & lt; String, Object & gt; highlights, arraylisthashmap

ArrayList <HashMap <String, Object> collection, arraylisthashmap

1. In Android, how does one pass the ArrayList <HashMap <String, Object> in an Activity to another activity?

Eg:

Storage: intent. putExtra ("arrayList", dataList );
(Remember to force type conversion ):
ArrayList <HashMap <String, Object> dataList = new ArrayList <HashMap <String, Object> ();
DataList = (ArrayList <HashMap <String, Object>) GetIntent (). getSerializableExtra ("arrayList ");

 

2. ArrayList <HashMap <String, Object> How do I update and delete key-value pairs?

Eg:

String[ ] name= new String[ ]{"James","Li Si","Wang Wu","Zhao six","Huo Qi"}; 

         ArrayList<HashMap<String, Object>> arrayList =  new  ArrayList<HashMap<String, Object>>();          for (  int  i= 0  ; i <name.length ; i++){               HashMap<String, Object> map =  new  HashMap<String, Object>();               map.put( "Name" , name[ i ]);               arrayList.add(map);          }          // Modify the key          for  (HashMap<String, Object> hashMap : arrayList)          {              if  (hashMap.get( "Name" ).equals( "Wang Wu" ))              {                  hashMap.put( "Name" ,  "James" );              }          }          // Officially recommended deletion method          Iterator<HashMap<String, Object>> iterator = arrayList.iterator();            while (iterator.hasNext())            {                if (iterator.next().get( "Name" ).equals( "Li Si" ))                {                    iterator.remove();                }            }           System.out.println(arrayList);                    Running result:          [{Name = James}, {Name = James}, {Name = Zhao 6}, {Name = Hoy 7}]  3.ArrayList <HashMap <String, Object> obtains data cyclically. Eg: Add data: Data = new ArrayList <Map <String, Object> ();

Map <String, Object> map1 = new HashMap <String, Object> ();

Map1.put ("username", et_username.getText (). toString (). trim ());

Map1.put ("password", et_password.getText (). toString (). trim ());

Data. add (map1 );

Valid value: For (Map <String, Object> m: Data ){

If (m! = Null ){

String username = m. get ("username"). toString (). trim ();

String password = m. get ("password"). toString (). trim ();

Et_username.setText (username );

Et_password.setText (password );

} Else {

Return;

}

}