在 sqlite 数据库的帮助下，我添加了板球运动员姓名，最后它在列表视图中显示了姓名。
我在 CustomCursorAdapter.java 中添加了更新和删除按钮。下面我发布了相应的适配器代码：
自定义CursorAdapter.java：
import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CursorAdapter;
import android.widget.TextView;
public class CustomCursorAdapter extends CursorAdapter {
public CustomCursorAdapter(Context context, Cursor c) {
super(context, c);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
// when the view will be created for first time,
// we need to tell the adapters, how each item will look
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View retView = inflater.inflate(R.layout.single_row_item, parent, false);
return retView;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
// here we are setting our data
// that means, take the data from the cursor and put it in views
TextView textViewPersonName = (TextView) view.findViewById(R.id.tv_person_name);
textViewPersonName.setText(cursor.getString(cursor.getColumnIndex(cursor.getColumnName(1))));
//Handle buttons and add onClickListeners
Button deleteBtn = (Button)view.findViewById(R.id.delete_btn);
Button updateBtn = (Button)view.findViewById(R.id.update_btn);
deleteBtn.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
notifyDataSetChanged();
}
});
updateBtn.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
//do something
notifyDataSetChanged();
}
});
}
}
single_row_item.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/update_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toLeftOf="@+id/delete_btn"
android:text="Update" />
<Button
android:id="@+id/delete_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="Delete" />
<TextView
android:id="@+id/tv_person_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/add_btn"
android:layout_alignBottom="@+id/add_btn"
android:layout_alignParentLeft="true"
android:paddingBottom="5dp"
android:text="Sample Data"
android:textSize="15sp" />
</RelativeLayout>
PersonDatabaseHelper.java：
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class PersonDatabaseHelper {
private static final String TAG = PersonDatabaseHelper.class.getSimpleName();
// database configuration
// if you want the onUpgrade to run then change the database_version
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "mydatabase.db";
// table configuration
private static final String TABLE_NAME = "person_table"; // Table name
private static final String PERSON_TABLE_COLUMN_ID = "_id"; // a column named "_id" is required for cursor
private static final String PERSON_TABLE_COLUMN_NAME = "person_name";
private static final String PERSON_TABLE_COLUMN_PIN = "person_pin";
private DatabaseOpenHelper openHelper;
private SQLiteDatabase database;
// this is a wrapper class. that means, from outside world, anyone will communicate with PersonDatabaseHelper,
// but under the hood actually DatabaseOpenHelper class will perform database CRUD operations
public PersonDatabaseHelper(Context aContext) {
openHelper = new DatabaseOpenHelper(aContext);
database = openHelper.getWritableDatabase();
}
public void insertData (String aPersonName, String aPersonPin) {
// we are using ContentValues to avoid sql format errors
ContentValues contentValues = new ContentValues();
contentValues.put(PERSON_TABLE_COLUMN_NAME, aPersonName);
contentValues.put(PERSON_TABLE_COLUMN_PIN, aPersonPin);
database.insert(TABLE_NAME, null, contentValues);
}
public Cursor getAllData () {
String buildSQL = "SELECT * FROM " + TABLE_NAME;
Log.d(TAG, "getAllData SQL: " + buildSQL);
return database.rawQuery(buildSQL, null);
}
// this DatabaseOpenHelper class will actually be used to perform database related operation
private class DatabaseOpenHelper extends SQLiteOpenHelper {
public DatabaseOpenHelper(Context aContext) {
super(aContext, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
// Create your tables here
String buildSQL = "CREATE TABLE " + TABLE_NAME + "( " + PERSON_TABLE_COLUMN_ID + " INTEGER PRIMARY KEY, " +
PERSON_TABLE_COLUMN_NAME + " TEXT, " + PERSON_TABLE_COLUMN_PIN + " TEXT )";
Log.d(TAG, "onCreate SQL: " + buildSQL);
sqLiteDatabase.execSQL(buildSQL);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) {
// Database schema upgrade code goes here
String buildSQL = "DROP TABLE IF EXISTS " + TABLE_NAME;
Log.d(TAG, "onUpgrade SQL: " + buildSQL);
sqLiteDatabase.execSQL(buildSQL); // drop previous table
onCreate(sqLiteDatabase); // create the table from the beginning
}
}
}
Output:
在上面的屏幕截图中，它显示了更新和删除按钮。如果我单击更新按钮，它必须显示一个警报对话框并编辑指定列表视图的名称并显示它。
然后，如果我单击“删除”按钮，它必须删除相应的列表视图行。
任何人都可以帮我解决这个问题。谢谢。
最后我自己完成了。但不是使用Cursor Adapter我在用Base Adapter得到输出。
我提到了这个Tutorial。我花了更多时间找到这个教程。它对我帮助很大。然后我对首页和我的要求进行了一些修改。
我像这样更改我的首页。下面我将展示 MainActivity 中的更改：
MainActivity.java：
public class MainActivity extends Activity implements OnClickListener {
private Button btn_add;
ActionBar actionBar;
private ListView listview;
DatabaseHelper db;
public ArrayList<ProductModel> _productlist = new ArrayList<ProductModel>();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btn_add = (Button) findViewById(R.id.btn_add);
btn_add.setOnClickListener(this);
listview = (ListView) findViewById(R.id.listview);
actionBar = getActionBar();
ColorDrawable colorDrawable = new ColorDrawable(
Color.parseColor("#000000"));
actionBar.setBackgroundDrawable(colorDrawable);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
_productlist.clear();
db = new DatabaseHelper(getApplicationContext());
db.getWritableDatabase();
ArrayList<ProductModel> product_list = db.getProudcts();
for (int i = 0; i < product_list.size(); i++) {
String tidno = product_list.get(i).getIdno();
System.out.println("tidno>>>>>" + tidno);
String tname = product_list.get(i).getProductname();
String tprice = product_list.get(i).getProductprice();
ProductModel _ProductModel = new ProductModel();
_ProductModel.setIdno(tidno);
_ProductModel.setProductname(tname);
_ProductModel.setProductprice(tprice);
_productlist.add(_ProductModel);
}
listview.setAdapter(new ListAdapter(this));
db.close();
}
private class ListAdapter extends BaseAdapter {
LayoutInflater inflater;
ViewHolder viewHolder;
public ListAdapter(Context context) {
// TODO Auto-generated constructor stub
inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return _productlist.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
if (convertView == null) {
convertView = inflater.inflate(R.layout.listview_row, null);
viewHolder = new ViewHolder();
viewHolder.txt_pname = (TextView) convertView
.findViewById(R.id.txtdisplaypname);
viewHolder.txt_pprice = (TextView) convertView
.findViewById(R.id.txtdisplaypprice);
viewHolder.txtidno = (TextView) convertView
.findViewById(R.id.txtdisplaypid);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.txt_pname.setText(_productlist.get(position)
.getProductname().trim());
viewHolder.txt_pprice.setText(_productlist.get(position)
.getProductprice().trim());
viewHolder.txtidno.setText(_productlist.get(position).getIdno()
.trim());
final int temp = position;
(convertView.findViewById(R.id.btn_update))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
String _productid = String.valueOf(_productlist
.get(temp).getIdno());
String _productname = _productlist.get(temp)
.getProductname();
String _productprice = _productlist.get(temp)
.getProductprice();
Intent intent = new Intent(MainActivity.this,
AddUpdateValues.class);
Bundle bundle = new Bundle();
bundle.putString("id", _productid);
bundle.putString("name", _productname);
bundle.putString("price", _productprice);
intent.putExtras(bundle);
startActivity(intent);
}
});
(convertView.findViewById(R.id.btn_delete))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
AlertDialog.Builder alertbox = new AlertDialog.Builder(
MainActivity.this);
alertbox.setCancelable(true);
alertbox.setMessage("Are you sure you want to delete ?");
alertbox.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(
DialogInterface arg0, int arg1) {
Log.i(">>>TEMP>>>", temp + "");
Log.i(">>>getIdno>>>>>>",
_productlist.get(temp)
.getIdno().trim()
+ "");
System.out
.println(">>>getIdno>>>>>>"
+ _productlist
.get(temp)
.getIdno()
.trim());
db.removeProduct(
_productlist.get(temp)
.getIdno().trim(),
"", "");
MainActivity.this.onResume();
Toast.makeText(
getApplicationContext(),
"Project Deleted...",
Toast.LENGTH_SHORT).show();
}
});
alertbox.setNegativeButton("No",
new DialogInterface.OnClickListener() {
public void onClick(
DialogInterface arg0, int arg1) {
}
});
alertbox.show();
}
});
return convertView;
}
}
private class ViewHolder {
TextView txt_pname;
TextView txt_pprice;
TextView txtidno;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.btn_add:
Intent addintent = new Intent(MainActivity.this, AddRecord.class);
startActivity(addintent);
break;
default:
break;
}
}
}
我希望这个答案对某人有帮助。