Question

首先，我想通知我正在创建一个Android应用程序，允许用户通过使用sqlite来存储数据来查看和注册联系人而且，我使用AsyncTask来执行插入和查看数据现在，我想知道我应该在哪里编写可点击的视图列表代码。
它应该写在backgroudTask或displaycontact页面中？有人能为我提供一些如何植入它的例子吗？这是示例代码和一些解释这是backgoundTask。

package com.example.assignment;

import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

public class BackgroundTask extends AsyncTask <String ,Contact, String> {

    Context ctx;
    ContactAdapter contactAdapter;
    Activity activity;
    ListView listView;
    BackgroundTask(Context ctx){
        this.ctx = ctx;
        activity = (Activity)ctx;

    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
    }

    @Override
    protected void onProgressUpdate(Contact... values) {
        contactAdapter.add(values[0]);
    }

    @Override
    protected String doInBackground(String... params) {
        // TODO Auto-generated method stub
        String method = params[0];
        DatabaseOperations databaseOperations = new DatabaseOperations(ctx);
        if (method.equals("add_info")){

            String cFamName  = params[1];
            String cFirName  = params[2];
            String cHouseNo   = params[3];
            String cStreet   = params[4];
            String cTown     = params[5];
            String cCountry  = params[6];
            String cPostcode = params[7];
            String cTelNo    = params[8];
            SQLiteDatabase db = databaseOperations.getWritableDatabase();
            databaseOperations.putInformation(db ,cFamName,cFirName,cHouseNo,cStreet,cTown,cCountry,cPostcode,cTelNo);
            return "One Row Inserted...";
        }
        else if(method.equals("get_info")){
            listView = (ListView)activity.findViewById(R.id.display_listview);
            SQLiteDatabase db = databaseOperations.getReadableDatabase(); 
                Cursor cursor = databaseOperations.getInformations(db);
                contactAdapter = new ContactAdapter(ctx, R.layout.display_contact_row);
                String cFamName, cFirName, cTelNo;
                while(cursor.moveToNext()){
                    cFamName = cursor.getString(cursor.getColumnIndex(TableData.TableInfo.eeFamName));
                    cFirName = cursor.getString(cursor.getColumnIndex(TableData.TableInfo.eeFirName));
                    cTelNo   = cursor.getString(cursor.getColumnIndex(TableData.TableInfo.eeTelNo));
                    Contact contact  = new Contact(cFamName, cFirName, cTelNo);
                    publishProgress(contact);
                }
                return "get_info";
        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        if(result.equals("get_info")){
            listView.setAdapter(contactAdapter);
        }
        else{
            Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
        }       
    }
}

这是DisplayContact代码，显示名为backgroudTask的联系人以显示列表。

package com.example.assignment;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class DisplayContact extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.display_contact);
        BackgroundTask backgroundTask = new BackgroundTask(this);
        backgroundTask.execute("get_info");
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.display_contact, menu);
        return true;
    }

}

这是我的contactAdaper

package com.example.assignment;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class ContactAdapter extends ArrayAdapter<Object> {

    List<Contact> list = new ArrayList<Contact>();

    public ContactAdapter(Context context, int resource) {
        super(context, resource);
        // TODO Auto-generated constructor stub
    }

    public void add(Contact object){
        list.add(object);
        super.add(object);
    }

    @Override
    public int getCount(){
        return list.size();
    }

    @Override
        public Object getItem(int position){
            return list.get(position);
        }

    @Override
    public  View getView(int position, View convertView, ViewGroup parent){
        View row = convertView;
        ContactHolder contactHolder;
        if(row==null){
            LayoutInflater layoutInflater =(LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = layoutInflater.inflate(R.layout.display_contact_row,parent,false);
            contactHolder = new ContactHolder();
            contactHolder.name = (TextView)row.findViewById(R.id.name);
            contactHolder.number = (TextView)row.findViewById(R.id.number);
            row.setTag(contactHolder); 
        }
        else{
            contactHolder = (ContactHolder)row.getTag();
        }

        Contact contact  = (Contact)getItem(position);
        contactHolder.name.setText(contact.getName().toString());
        contactHolder.number.setText(contact.getTelNo().toString());
    return row;
    }

    static class ContactHolder{
        TextView name, number;
    }

}

Answer 1

这取决于您需要该代码的位置。

如果只在一个活动/片段中需要它，请将其放在该活动/片段中。如果你需要它进入很多领域，最好的方法是在你复制的对象上实现一个函数（片段？自定义对象？任务？），并在执行单击时使用适当的参数调用该函数。

例如，您可以让asyncTask扩展“OnClickListener”，并使用CREATE FUNCTION [dbo].[fn_GetAEAssumptionFacts] ( @pScenarioName varchar(500) = NULL ,@pBuildingID varchar(500) = NULL ,@pLeaseID varchar(500) = NULL ,@pTenantName varchar(500) = NULL ) RETURNS TABLE AS RETURN select ..... from ae11.dbo.rvw_FinancialLineItems fli .... INNER JOIN ae11.dbo.rvw_Scenarios s on s.Id = pas.ScenarioId left join (select externalID, PropertyAssetId, LeaseID, BeginDate from ae11.dbo.ivw_Leases WHERE PropertyAssetID IN (select ID from AE11.dbo.PropertyAssets where scenarioID = (CASE WHEN isnull(@pScenarioName, '') = '' THEN (select ID from AEX.[dbo].[ConfigurationFieldTable] where [Type] = 'Lease Connect Current Scenario' ) ELSE @pScenarioName END) ) ) lea ON lea.LeaseID = uni.ExternalID AND lea.PropertyAssetID = uni.PropertyAssetId where 1=1 ...... AND s.id = (CASE WHEN isnull(@pScenarioName, '') = '' THEN (select ID from AEX.[dbo].[ConfigurationFieldTable] where [Type] = 'Lease Connect Current Scenario' ) ELSE @pScenarioName END)。如果你需要更多的参数，你可以在asyncTask中有一个函数，比如“doOnClick（View view，param1，param2 ...）”然后使用匿名的onClickListener：

button.setOnClickListener(asyncTask);

您的第一步是了解您的需求：本地代码？可重用的？...然后在将要复制的内容（或在活动中）实现该功能。

放置可点击的listView代码的合适页面在哪里

1 个答案: