我正在开发一个android应用程序。我希望显示从数据库中选择的数据并将其显示在listview中。首先，我使用静态数据显示实习生（用户）数据。这是静态的。然后在相同的功能后我使用sqlite数据库并注册实习生（用户），现在我想在listview中显示注册的trainne的名字。我刚刚完成了下面的代码。任何人都可以帮我如何在列表视图中显示受训者姓名。
AddTraineeActivity.java 该文件的作用是创建实习数据库的基本功能，并插入实习生的值：
package com.example.gymapp;
import android.app.Activity;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.text.InputType;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class AddTraineeActivity extends Activity implements OnClickListener
{
EditText fn;
EditText ln;
EditText un;
EditText pwd;
EditText pno;
EditText age;
Button btnAdd;
SQLiteDatabase db = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_managetrainee);
fn = (EditText) findViewById(R.id.etfirstname);
ln = (EditText) findViewById(R.id.etlastname);
age = (EditText) findViewById(R.id.edage);
pno = (EditText) findViewById(R.id.etphoneno);
un = (EditText) findViewById(R.id.ettraineeun);
pwd = (EditText) findViewById(R.id.etpwdtrainee);
btnAdd = (Button) findViewById(R.id.btnsavedata);
db=openOrCreateDatabase("mydb", MODE_PRIVATE, null);
db.execSQL("create table if not exists trainee(firstname text, lastname text,age varchar,phoneNumber varchar,userTrainee varchar,passwordTrainee varchar)");
btnAdd.setOnClickListener(this);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
//overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right);
}
public void show(String str)
{
Toast.makeText(this, str, Toast.LENGTH_LONG).show();
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(v== btnAdd)
{
String firstname = fn.getText().toString();
String lastname = ln.getText().toString();
String Age = age.getText().toString();
String phoneNumber = pno.getText().toString();
String usernameTrainee = un.getText().toString();
String passwordTrainee = pwd.getText().toString();
if(firstname==null||firstname==""||firstname.length()<3)
{
show("Please Enter Correct Name.");
}
else if(lastname==null||lastname==""||lastname.length()<2)
{
show("Please Enter Correct Name.");
}
else if(Age==null||Age==""||Age.length()>3)
{
show("Please Enter Correct Age.");
}
else if(phoneNumber==null||phoneNumber==""||phoneNumber.length()<10)
{
show("Please Enter Correct mobile number.");
}
else if(usernameTrainee==null||usernameTrainee==""||usernameTrainee.length()<4)
{
show("Please Enter valid User name.");
}
else if(passwordTrainee==null||passwordTrainee==""||passwordTrainee.length()<6)
{
show("Please Enter Strong Password.");
}
else
{
db.execSQL("insert into trainee values('"+firstname+"','"+lastname+"','"+Age+"','"+phoneNumber+"','"+usernameTrainee+"','"+passwordTrainee+"')");
//i=new Intent(this,Welcome.class);
//startActivityForResult(i, 500);
//overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
db.close();
finish();
}
}
}
}`
UserListActivity.java 此文件包含在listview中显示受训者姓名的代码。但此文件显示静态用户，例如trainee1，trainee2，trainee3 .... trainee13。
package com.example.gymapp;
import com.tss.constant.Constant;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.content.Context;
import android.database.sqlite.*;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.Cursor;
import com.example.gymapp.AddTraineeActivity;
import com.example.gymapp.dao.DBfitguidehelper;
public class UserListActivity extends Activity {
private ListView listViewUser;
private String loggedInType ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_list);
//SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
//queryBuilder.setTables(DBfitguidehelper.)
listViewUser = (ListView)findViewById(R.id.listViewUser);
String[] values = new String[]{"trainee", "trainee1", "trainee2", "trainee3", "trainee4", "trainee5", "trainee6", "trainee7", "trainee8", "trainee9", "trainee10", "trainee11", "trainee12", "trainee13"};
ArrayAdapter<String> userAdapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, android.R.id.text1, values);
listViewUser.setAdapter(userAdapter);
listViewUser.setOnItemClickListener(new ListViewListner());
if(savedInstanceState!=null){
Bundle extras = getIntent().getExtras();
loggedInType = extras.getString("loggedInType");
System.out.println("loggedInType - " + loggedInType);
}
}
private class ListViewListner implements OnItemClickListener{
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position, long id) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), "selected user is " + listViewUser.getItemAtPosition(position), Toast.LENGTH_SHORT).show();
Constant.Selected_Trainee = ""+listViewUser.getItemAtPosition(position);
Intent intent = new Intent(getApplicationContext(),TrainerActivity.class);
intent.putExtra("loggedInType", loggedInType);
Toast.makeText(getApplicationContext(), "loggedInType"+loggedInType, Toast.LENGTH_SHORT).show();
startActivity(intent);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.user_list, menu);
return true;
}
}
现在我想显示存储在数据库中的学员姓名。任何人都可以帮助我吗？