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[Android] Activity之間如何透過Intent傳遞複雜結構的data

2015-06-19 16:49 429 查看

原文链接：http://jimmy319.blogspot.tw/2011/12/android-activityintentdata-structure.html

Application是由許多Activities所組成，不同Activity之間是藉由Intent物件來進行啟動/關閉，Intent物件可以帶入data傳遞給它所喚起的Activity，它可能是上個Activity執行後的結果。

在Intentobject加入data最常見的方法即為putExtra()，它提供了多種overload方法，包含各種primitivedatatype以及其Array資料型態，另外它也支援實作Serializable與Parcelable兩種介面的資料型態。

當遇到需要傳遞較複雜的資料型態(自定義且putExtra沒有對應的多載函式)給即將開啟的Activity，例如：Customlistview'sdatasource就常使用HashMap、ArrayList等資料型態的組合，這些都是實作Serializable常見的類別，此時就可以採用putExtra(Stringname,Serializablevalue)將資料帶入Intentobject，接受端Activity再透過getSerializableExtra(Stringname)取得自定義的Serializable
data，藉此達到傳遞複雜資料的目的。

以下將示範透過Intent將自定義資料型態ArrayList<HashMap>傳遞給CustomListView作為其Adapter之資料來源。

程式碼說明

一、建立負責activateListActivity之Activity

01	package com.intentdemo;

03	import java.util.ArrayList;

04	import java.util.HashMap;

06	import android.app.Activity;

07	import android.content.Intent;

08	import android.os.Bundle;

09	import android.view.View;

11	public class IntentDemoActivity extends Activity {

13	private int [] icons={

14	R.drawable.icon1,R.drawable.icon2,

15	R.drawable.icon3,R.drawable.icon4,

16	R.drawable.icon5,R.drawable.icon6

};

19	private String[] names={

20	"role1" , "role2" ,

21	"role3" , "role4" ,

22	"role5" , "role6"

};

25	private String[] tels={

26	"000-11111" , "999-19191" ,

27	"000-22222" , "919-49791" ,

28	"101-33333" , "929-29391"

};

@Override

32	public void onCreate(Bundle savedInstanceState){

33	super .onCreate(savedInstanceState);

34	setContentView(R.layout.main);

IntentDemoActivity.java
二、宣告自定義資料型態

01	private ArrayList< HashMap<String,Object>>getListData(){

02	ArrayList dataSet= new ArrayList();

03	for ( int i= 0 ;i< 6 ;i++){

04	HashMap< String,Object>data= new HashMap< String,Object>();

05	data.put( "icon" , icons[i]);

06	data.put( "name" , names[i]);

07	data.put( "tel" , tels[i]);

08	dataSet.add(data);

10	return dataSet;

三、按鈕click事件觸發Intent並附帶自定義data

1	public void onIntentButtonClick(View v){

2	Intent intent= new Intent();

3	intent.putExtra( "listData" , getListData());

4	intent.setClass( this , RoleListActivity. class );

5	startActivity(intent);

四、CustomListActivity透過getSerializableExtra()接收data並將其設為ListViewAdapter資料來源

01	package com.intentdemo;

03	import java.util.ArrayList;

04	import java.util.HashMap;

06	import android.app.ListActivity;

07	import android.os.Bundle;

09	public class RoleListActivity extends ListActivity {

@Override

12	public void onCreate(Bundle savedInstanceState){

13	super .onCreate(savedInstanceState);

14	setContentView(R.layout.role_list);

16	//get intentdata

17	ArrayList< HashMap<String,Object>>data=

18	(ArrayList< HashMap<String,Object>>)getIntent()

19	.getSerializableExtra( "listData" );

20	this .setListAdapter( new ListAdapter( this ,data));

RoleListActivity.java

01	package com.intentdemo;

03	import java.util.ArrayList;

04	import java.util.HashMap;

06	import android.content.Context;

07	import android.view.LayoutInflater;

08	import android.view.View;

09	import android.view.ViewGroup;

10	import android.widget.BaseAdapter;

11	import android.widget.ImageView;

12	import android.widget.TextView;

14	public class ListAdapter extends BaseAdapter {

16	private ArrayList< hashmap<string,object>>data;

17	private LayoutInflater inflater;

19	public ListAdapter(Context c,ArrayList<HashMap<String,Object>>d){

20	inflater=LayoutInflater.from(c);

data=d;

@Override

25	public int getCount() {

26	return data.size();

@Override

30	public Object getItem( int index) {

31	return data.get(index);

@Override

35	public long getItemId( int index) {

36	return index;

@Override

40	public View getView( int i, Viewv,ViewGroupp){

41	ViewHolder holder;

42	if (v== null ){

43	v=inflater.inflate(R.layout.role_list_row, null );

44	holder= new ViewHolder();

45	holder.icon=(ImageView)v.findViewById(R.id.icon);

46	holder.nameTxt=(TextView)v.findViewById(R.id.name);

47	holder.telTxt=(TextView)v.findViewById(R.id.tel);

48	v.setTag(holder);

else

50	holder=(ViewHolder)v.getTag();

53	holder.icon.setImageResource((Integer)data.get(i).get( "icon" ));

54	holder.nameTxt.setText((String)data.get(i).get( "name" ));

55	holder.telTxt.setText((String)data.get(i).get( "tel" ));

return

v;

60	static class ViewHolder{

61	ImageView icon;

62	TextView nameTxt;

63	TextView telTxt;

66	</string,object>

ListAdapter.java

01	<? xml version = "1.0" encoding = "utf-8" ?>

02	< LinearLayout

03	xmlns:android = "http://schemas.android.com/apk/res/android"

04	android:layout_width = "match_parent"

05	android:layout_height = "match_parent"

06	android:orientation = "vertical" >

07	< ListView

08	android:id = "@android:id/list"

09	android:layout_width = "match_parent"

10	android:layout_height = "match_parent"

/>

12	</ LinearLayout >

role_list.xml

01	<? xml version = "1.0" encoding = "utf-8" ?>

02	< LinearLayout

03	xmlns:android = "http://schemas.android.com/apk/res/android"

04	android:layout_width = "match_parent"

05	android:layout_height = "100dp"

06	android:orientation = "horizontal" >

07	< ImageView

08	android:id = "@+id/icon"

09	android:layout_width = "90dp"

10	android:layout_height = "90dp"

11	android:padding = "5dp"

/>

14	< LinearLayout

15	android:layout_width = "match_parent"

16	android:layout_height = "match_parent"

17	android:gravity = "center_vertical"

18	android:orientation = "vertical"

20	< TextView

21	android:id = "@+id/name"

22	android:layout_width = "match_parent"

23	android:layout_height = "wrap_content"

24	android:gravity = "center"

25	android:textSize = "20sp"

/>

27	< TextView

28	android:id = "@+id/tel"

29	android:layout_width = "match_parent"

30	android:layout_height = "wrap_content"

31	android:gravity = "center"

32	android:textSize = "20sp"

/>

34	</ LinearLayout >

35	</ LinearLayout >

role_list_row.xml

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