androidliststring
❶ android green怎麼怎麼在entity里保存list<String>
可以建立one-to-many的關系,但是個人覺得這種方式不是很合適,沒有必要,建議還是讓伺服器端把返回的list<String>轉換成 xxxx,xxx,xxxxx,這樣的字元串 然後直接保存到資料庫比較方便
❷ 如何在Android中使用listview
創建繼承BaseAdapter並實現其抽象方法的類MyListViewAdapter
說明
下面的講解中,只創建自定義的適配器類,如何使用請參考android中常用控制項的使用之ListView
1.創建類MyListViewAdapter
創建類MyListViewAdapter,該類繼承BaseAdapter,並實現其抽象方法:
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int getCount();
Object getItem(int position);
long getItemId(int position);
View getView(int position,View convertView,ViewGroup parent);
getCount需要返回有多少個item,也就是說如昌姿最會在listview中展示這么多行
getItem需要返回參數position位置的數據
getItemId返回position就行了
2.給MyListViewAdapter類添加成員變數和構造方法
兩個成員變數
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List<String> list;
Context context;
list表示要顯示的數據,context變數在生成View對象時需要用到
構造方法:構造方法是為了給兩個成員變數賦值
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public MyListViewAdapter(List<String> list , Context context) {
this.list = list;
this.context = context;
}
3.給getCount,getItem,getItemId方法添加代碼
getCount需要返回有多少個item,也就是說最會在listview中展示這么多行,所以返回list.size
getItem需要返回參數position位置的數據,也就是list中第position項的值list.get(position)
getItemId返回position就行了
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@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
4.給getView方法添加代碼
getView方法是返回位置為position的View對象,第迅明二個參數convertView考慮到資源重用問題,在上下滑動的過程中,需要顯示某項的時候才會調用getView方法,而如果有某項被隱藏不顯示,就會把不顯示那一行的View作為convertView參數傳入,如果沒有某項被隱藏,convertView值為null。可以通過下面代碼中的if(convertView!=null)中的輸出來渣絕看哪一行被隱藏了。
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@Override
public View getView(int position, View convertView, ViewGroup parent) {
System.out.println("調用getView方法,顯示position="+position+"項");
if(convertView!=null){
TextView t = (TextView) convertView.findViewById(R.id.firstTextView);
System.out.println(t.getText());
}else{
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = layoutInflater.inflate(R.layout.item_mylistviewadapter, null);
}
TextView t = (TextView)(convertView.findViewById(R.id.firstTextView));
t.setText(list.get(position));
if(position%2==0)
{
t.setBackgroundColor(Color.WHITE);
}
else{
t.setBackgroundColor(Color.GRAY);
}
return convertView;
}
補充:通過xml生成View對象
通過Context對象生成一個LayoutInflater對象
調用LayoutInflater對象的inflate方法生成控制項對象,inflate方法的第一個參數為xml文件,第二個參數一般為null。返回值為該xml文件最外層的標簽對象。
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LayoutInflater layoutInflater =(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout convertView =(LinearLayout)layoutInflater.inflate(R.layout.item_mylistvie
源代碼下載
pan..com/s/1ntuQDdv
❸ android開發中如何講一個list數組轉換成String字元串的形式
public class SplitTest {
public static void main(String args[]) {
String str = "a1.png,a2.png,a3.png";// 原始字元串
String[] arrayStr = new String[] {};// 字元數組
List<String> list = new ArrayList<String>();// list
arrayStr = str.split(",");// 字元串轉字元數組
list = java.util.Arrays.asList(arrayStr);// 字元數組轉list
String[] storeStr = list.toArray(new String[list.size()]);// list轉成字元數組
/* 輸出字元數組的值 */
for (String s : arrayStr) {
System.out.println(s);
}
System.out.println("-------------");
/* 輸出list值 */
for (String s : list) {
System.out.println(s);
}
System.out.println("-------------");
for (String s : storeStr) {
System.out.println(s);
}
System.out.println("-------------");
}
}
❹ android 怎麼取list數據
按以下代碼可獲取到list數據:
package com.example.sdtg.sdsw;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.SoapFault;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import org.xmlpull.v1.XmlPullParserException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
public class ListActivity extends Activity {
// 命名空間
// String nameSpace = "http://tempuri.org/";
// 調用的方法名稱
// String methodName = "GetSjSearch";
// EndPoint
// String endPoint = "http://192.168.0.145/webservice2/gswebservice.asmx";
// SOAP Action
// String soapAction = "http://tempuri.org/GetSjSearch";
// List<Map<String, Object>> mList;
ListView ListV;
HashMap<String, Object> map = new HashMap<String, Object>();
private List<Map<String,String>> listItems;
SimpleAdapter mListAdapter;
String name="";
String addr="";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
listItems = new ArrayList<Map<String,String>>();
ListV=(ListView)findViewById(R.id.ListView01);
Handler indicate = new Handler();
//獲取主頁面傳的值
final Intent data = getIntent();
name=data.getStringExtra("Name");
addr=data.getStringExtra("Addr");
new NetAsyncTask().execute();
ListV.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
//獲得選中項的HashMap對象
TextView viewtmc = (TextView) arg1.findViewById(R.id.textListmc);
TextView viewdz = (TextView) arg1.findViewById(R.id.textlistdz);
TextView viewid = (TextView) arg1.findViewById(R.id.textlistid);
//String playerChanged = c.getText().toString();
Bundle bundle = new Bundle();
bundle.putString("Name", viewtmc.getText().toString());
bundle.putString("Addr", viewdz.getText().toString());
bundle.putString("ID", viewid.getText().toString());
final Intent data = getIntent();
data.putExtras(bundle);
//跳轉回MainActivity
//注意下面的RESULT_OK常量要與回傳接收的Activity中onActivityResult()方法一致
ListActivity.this.setResult(RESULT_OK, data);
//關閉當前activity
ListActivity.this.finish();
}
});
};
class NetAsyncTask extends AsyncTask<Object, Object, String> {
@Override
protected void onPostExecute(String result) {
if (result.equals("success")) {
mListAdapter = null;
mListAdapter = new SimpleAdapter(ListActivity.this, listItems, R.layout.item,new String[]{"title", "info", "img"}, new int[]{R.id.textListmc, R.id.textlistdz, R.id.textlistid});
ListV.setAdapter(mListAdapter);
}
super.onPostExecute(result);
}
@Override
protected String doInBackground(Object... params) {
// 命名空間
String nameSpace = "http://tempuri.org/";
// 調用的方法名稱
String methodName = "GetSjSearch";
// EndPoint
String endPoint = "http://192.168.0.145/webservice2/gswebservice.asmx";
// SOAP Action
String soapAction = "http://tempuri.org/GetSjSearch";
// 指定WebService的命名空間和調用的方法名
SoapObject rpc = new SoapObject(nameSpace, methodName);
// 設置需調用WebService介面需要傳入的兩個參數mobileCode、userId
rpc.addProperty("name", name);
rpc.addProperty("address", addr);
// 生成調用WebService方法的SOAP請求信息,並指定SOAP的版本
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
SoapEnvelope.VER11);
// SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER12);
envelope.bodyOut = rpc;
// 設置是否調用的是dotNet開發的WebService
envelope.dotNet = true;
// 等價於envelope.bodyOut = rpc;
envelope.setOutputSoapObject(rpc);
HttpTransportSE transport = new HttpTransportSE(endPoint);
try {
// 調用WebService
transport.call(soapAction, envelope);
} catch (Exception e) {
e.printStackTrace();
}
SoapObject object;
// 開始調用遠程方法
try {
object = (SoapObject) envelope.getResponse();
int count = object.getPropertyCount();
// 得到伺服器傳回的數據
int count1 = object.getPropertyCount();
if(count1>0)
{
for (int i = 0; i < count1; i++) {
Map<String,String> listItem = new HashMap<String, String>();
SoapObject soapProvince = (SoapObject)object.getProperty(i);
listItem.put("title", soapProvince.getProperty("DJXX_NSRMC").toString());
listItem.put("info", soapProvince.getProperty("DJXX_ZCDJ").toString());
//listItem.put("img", soapProvince.getProperty("DJXX_NSRSBH").toString());
listItems.add(listItem);
}}
} catch (IOException e) {
e.printStackTrace();
//return "IOException";
}
return "success";
}
}
}
❺ Android是怎麼對對數據源中list<String>欄位進行Parcelable序列化的
ArrayList<String> photos;
寫入
dest.writeStringList(photos);
讀取
this.photos=new ArrayList<>();
in.readStringList(this.photos);
注意加粗地方,另一個人回答錯了!