Question

我正在创建一个数据库中保存数据的应用程序。但我缺乏使用游标适配器在列表视图中显示数据。不知道应该写什么代码。请检查。

这是我的代码： MainActivity.java

package com.example.employeedetailsnew;

import java.text.SimpleDateFormat;
import java.util.Calendar;

import android.app.Activity;
import android.app.ActionBar;
import android.app.AlertDialog;
import android.app.Fragment;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;
import android.os.Build;

public class MainActivity extends Activity {


        private EditText nme = null;
        private EditText num = null;
        private EmployeeDatabase empObj;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            nme = (EditText) findViewById(R.id.name);
            num = (EditText) findViewById(R.id.ageemp);
            Button btnShowData = (Button) findViewById(R.id.button1);

              btnShowData.setOnClickListener(new Button.OnClickListener() {

              @Override 
              public void onClick(View v) {

                  onSaveClick();


              } });



        }

        public void onButtonClicked(View view) {
                Calendar c = Calendar.getInstance();
                SimpleDateFormat sdf = new SimpleDateFormat("dd:MMMM:yyyy HH:mm:ss a");
                String strDate = sdf.format(c.getTime());
                String varName = nme.getText().toString();
                String varAge = num.getText().toString();

                empObj = new EmployeeDatabase(getApplicationContext());
                empObj.insert(varName,varAge,strDate);

                AlertDialog alertDialog = null;
                alertDialog = new AlertDialog.Builder(MainActivity.this).create();
                alertDialog.setTitle("Message");
                alertDialog.setMessage("You have been Registered");
                alertDialog.setCancelable(true);
                alertDialog.show();
                nme.setText("");
                num.setText("");



        }

        public void onSaveClick(){

            Intent intent = new Intent(this, ShowData.class);
            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.main, menu);
            return true;
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            int id = item.getItemId();
            if (id == R.id.action_settings) {
                return true;
            }
            return super.onOptionsItemSelected(item);
        }

    }

EmployeeDatabse.java

package com.example.employeedetailsnew;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class EmployeeDatabase extends SQLiteOpenHelper{

    EmployeeDatabase (Context context) {
    super(context, "empdb.db", null,3);

    }



@Override
public void onCreate(SQLiteDatabase database)
{

    // create your table here
    database.execSQL(
            "create table employeedetailnew" +
    "(name TEXT , age TEXT, time TEXT)"
                    );



}
@Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion)
{
    database.execSQL("DROP TABLE IF EXISTS EMPLOYEEDETAILNEW");
    onCreate(database);
// handle database schema upgrades in here  
}

public Cursor getDetails()
{
    SQLiteDatabase db = getReadableDatabase();
    return db.rawQuery("select name, age from employeedetailnew", null);
}
public void insert(String name, String age, String time)
{
    long rowId = 0;
    try{
    SQLiteDatabase db = getWritableDatabase();
    ContentValues contentValues = new ContentValues(); 
    contentValues.put("name", name);
    contentValues.put("age", age);
    contentValues.put("time", time);
    rowId = db.insert("employeedetailnew", null, contentValues);


    }catch(Exception e){
        e.printStackTrace();
    }
    finally{
        System.out.println("The rowId is "+rowId);
        System.out.println("Name is "+name);
        System.out.println("Age is "+age);
        System.out.println("Time is "+time);
    }


    // insert into database here
}

public boolean deleteTitle(String name) 
{
    // incomplete delete code..:(
    SQLiteDatabase db = getWritableDatabase();
    return db.delete("employeedetailnew", name + "=" + name, null) > 0;
}
}

EmployeeDetailAdapter.java

package com.example.employeedetailsnew;



import java.util.ArrayList;

import android.content.Context;
import android.database.Cursor;
import android.support.v4.widget.CursorAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class EmployeeDetailAdapter extends CursorAdapter

{


    public EmployeeDetailAdapter(Context context, Cursor c) {
        super(context, c);
        // TODO Auto-generated constructor stub
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int index, View view, ViewGroup parent) {
        // TODO Auto-generated method stub
        if (view == null)
        {
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            view = inflater.inflate(R.layout.shows_view, parent, false);
        }

        EmployeeOther empDtl = times.get(index);

        TextView nameTextView = (TextView) view.findViewById(R.id.name1);
        nameTextView.setText(empDtl.getName());


        TextView ageTextView = (TextView) view.findViewById(R.id.age2);
        ageTextView.setText(empDtl.getAge());


        TextView timeTextView = (TextView) view.findViewById(R.id.time3);
        timeTextView.setText(empDtl.getTime());
        return view;
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // TODO Auto-generated method stub
        TextView nameTextView = (TextView) view.findViewById(R.id.name1);
        nameTextView.setText(cursor.getString(cursor.getColumnIndex("name")));

        TextView ageTextView = (TextView) view.findViewById(R.id.name1);
        ageTextView.setText(cursor.getString(cursor.getColumnIndex("age")));

        TextView timeTextView = (TextView) view.findViewById(R.id.name1);
        timeTextView.setText(cursor.getString(cursor.getColumnIndex("time")));
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        // TODO Auto-generated method stub
         LayoutInflater inflater = LayoutInflater.from (parent.getContext());
         View view = inflater.inflate(R.layout.shows_list, parent, false);
         return view; 
    }

}

ShowData.java

package com.example.employeedetailsnew;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.ListActivity;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class ShowData extends ListActivity


{
    private EmployeeDatabase databaseHelper;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);




        EmployeeDatabase empClick = new EmployeeDatabase(getApplicationContext());
        Cursor cursor = empClick.getDetails();
        if (cursor.moveToFirst()) 
        { 
            do 
            { 
                String name = cursor.getString(1); 
                String notes = cursor.getString(2);
                String time = cursor.getString(3);
                // something must be written here
                } while (cursor.moveToNext());
            }
        if (!cursor.isClosed()) 
        { 
            cursor.close();
        }

        }
    }

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.employeedetailsnew.MainActivity$PlaceholderFragment" >

    <EditText
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/empname"
        android:layout_below="@+id/empname"
        android:layout_marginTop="19dp"
        android:ems="10"
        android:inputType="textPersonName" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/sub"
        android:layout_below="@+id/sub"
        android:layout_marginTop="24dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_below="@+id/textView1" />

    <TextView
        android:id="@+id/empname"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="46dp"
        android:layout_marginTop="27dp"

        android:text="@string/name_of_the_employee" />

    <TextView
        android:id="@+id/age"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/name"
        android:layout_below="@+id/name"
        android:layout_marginTop="16dp"

        android:text="@string/age_of_the_employee" />

    <EditText
        android:id="@+id/ageemp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/age"
        android:layout_below="@+id/age"
        android:ems="10"
        android:inputType="numberSigned" />

    <Button
        android:id="@+id/sub"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignRight="@+id/button1"
        android:layout_centerVertical="true"
        android:onClick="onButtonClicked"
        android:text="@string/sub" />

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/textView1"
        android:layout_centerHorizontal="true"
        android:text="@string/show_data" />


  </RelativeLayout>

shows_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </ListView>

</LinearLayout>

shows_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/name1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />

    <TextView
        android:id="@+id/age2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />

    <TextView
        android:id="@+id/time3"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />

</LinearLayout>

Answer 1

使用以下代码

更改getDetails()的{{1}}

EmployeeDatabase

并更改public Cursor getDetails() { SQLiteDatabase db = getReadableDatabase(); return db.rawQuery("select rowid _id,name, age,time from employeedetailnew", null); } ShowData.java's，如下所示，

onCreate()

并浏览@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); EmployeeDatabase empClick = new EmployeeDatabase(getApplicationContext()); Cursor cursor = empClick.getDetails(); if(cursor !=null) getListView().setAdapter( new android.support.v4.widget.SimpleCursorAdapter(EmptyClass.this, R.layout.shows_view, cursor, new String[] { "name", "age", "time" }, new int[] {R.id.name1,R.id.age2,R.id.time3}, 0)); }和this example

Answer 2

*使用以下代码*更改EmployeeDatabase的getDetails（）

public Cursor getDetails() {
SQLiteDatabase db = getReadableDatabase();
return db.rawQuery("select rowid _id,name, age,time from employeedetailnew", null);}

并更改ShowData.java的onCreate（），如下所示

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    EmployeeDatabase empClick = new EmployeeDatabase(getApplicationContext());
    Cursor cursor = empClick.getDetails();
    if(cursor !=null)
        getListView().setAdapter(
            new android.support.v4.widget.SimpleCursorAdapter(EmptyClass.this, R.layout.shows_view, cursor, new String[] {
                    "name", "age", "time"
            }, new int[] {R.id.name1,R.id.age2,R.id.time3}, 0));
}

使用游标适配器显示从sqlite到listview的数据

2 个答案: