我想创建一个自定义的ListView,其中每一行都有一个TextView和一个ImageView(我将用它来选中/取消选中列表项),如下图所示:
我想从列表中删除多个项目。如何实现??你能否提供任何教程、参考或链接来学习这个??
![enter image description here](https://istack.dev59.com/Q6yaQ.webp)
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.ActivityInfo;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class DeleteData extends Activity {
Cursor cursor;
ListView lv_delete_data;
static ArrayList<Integer> listOfItemsToDelete;
SQLiteDatabase database;
private Category[] categories;
ArrayList<Category> categoryList;
private ArrayAdapter<Category> listAdapter;
ImageView iv_delete;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_delete_data);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
manage_reload_list();
listOfItemsToDelete = new ArrayList<Integer>();
iv_delete = (ImageView) findViewById(R.id.imageViewDeleteDataDelete);
iv_delete.setClickable(true);
iv_delete.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (listOfItemsToDelete.isEmpty()) {
Toast.makeText(getBaseContext(), "No items selected.",
Toast.LENGTH_SHORT).show();
}
else {
showDialog(
"Warning",
"Are you sure you want to delete these categories ? This will erase all records attached with it.");
}
}
});
lv_delete_data = (ListView) findViewById(R.id.listViewDeleteData);
lv_delete_data.setAdapter(listAdapter);
lv_delete_data.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
ImageView imageView = (ImageView) arg1
.findViewById(R.id.imageViewSingleRowDeleteData);
Category category = (Category) imageView.getTag();
if (category.getChecked() == false) {
imageView.setImageResource(R.drawable.set_check);
listOfItemsToDelete.add(category.getId());
category.setChecked(true);
} else {
imageView.setImageResource(R.drawable.set_basecircle);
listOfItemsToDelete.remove((Integer) category.getId());
category.setChecked(false);
}
}
});
}
private void showDialog(final String title, String message) {
AlertDialog.Builder adb = new Builder(DeleteData.this);
adb.setTitle(title);
adb.setMessage(message);
adb.setIcon(R.drawable.ic_launcher);
String btn = "Ok";
if (title.equals("Warning")) {
btn = "Yes";
adb.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
}
adb.setPositiveButton(btn, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
if (title.equals("Warning")) {
for (int i : listOfItemsToDelete) {
// -------first delete from category table-----
database.delete("category_fields", "cat_id=?",
new String[] { i + "" });
// --------now fetch rec_id where cat_id =
// i-----------------
cursor = database.query("records_data",
new String[] { "rec_id" }, "cat_id=?",
new String[] { i + "" }, null, null, null);
if (cursor.getCount() == 0)
cursor.close();
else {
ArrayList<Integer> al_tmp_rec_id = new ArrayList<Integer>();
while (cursor.moveToNext())
al_tmp_rec_id.add(cursor.getInt(0));
cursor.close();
for (int i1 : al_tmp_rec_id) {
database.delete("records_fields_data",
"rec_id=?", new String[] { i1 + "" });
database.delete("record_tag_relation",
"rec_id=?", new String[] { i1 + "" });
}
// ---------delete from records_data-------
database.delete("records_data", "cat_id=?",
new String[] { i + "" });
cursor.close();
}
}
showDialog("Success",
"Categories, with their records, deleted successfully.");
} else {
database.close();
listOfItemsToDelete.clear();
manage_reload_list();
lv_delete_data.setAdapter(listAdapter);
}
}
});
AlertDialog ad = adb.create();
ad.show();
}
protected void manage_reload_list() {
loadDatabase();
categoryList = new ArrayList<Category>();
// ------first fetch all categories name list-------
cursor = database.query("category", new String[] { "cat_id",
"cat_description" }, null, null, null, null, null);
if (cursor.getCount() == 0) {
Toast.makeText(getBaseContext(), "No categories found.",
Toast.LENGTH_SHORT).show();
cursor.close();
} else {
while (cursor.moveToNext()) {
categories = new Category[] { new Category(cursor.getInt(0),
cursor.getString(1)) };
categoryList.addAll(Arrays.asList(categories));
}
cursor.close();
}
listAdapter = new CategoryArrayAdapter(this, categoryList);
}
static class Category {
String cat_name = "";
int cat_id = 0;
Boolean checked = false;
Category(int cat_id, String name) {
this.cat_name = name;
this.cat_id = cat_id;
}
public int getId() {
return cat_id;
}
public String getCatName() {
return cat_name;
}
public Boolean getChecked() {
return checked;
}
public void setChecked(Boolean checked) {
this.checked = checked;
}
public boolean isChecked() {
return checked;
}
public void toggleChecked() {
checked = !checked;
}
}
static class CategoryViewHolder {
ImageView imageViewCheck;
TextView textViewCategoryName;
public CategoryViewHolder(ImageView iv_check, TextView tv_category_name) {
imageViewCheck = iv_check;
textViewCategoryName = tv_category_name;
}
public ImageView getImageViewCheck() {
return imageViewCheck;
}
public TextView getTextViewCategoryName() {
return textViewCategoryName;
}
}
static class CategoryArrayAdapter extends ArrayAdapter<Category> {
LayoutInflater inflater;
public CategoryArrayAdapter(Context context, List<Category> categoryList) {
super(context, R.layout.single_row_delete_data,
R.id.textViewSingleRowDeleteData, categoryList);
inflater = LayoutInflater.from(context);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Category category = (Category) this.getItem(position);
final ImageView imageViewCheck;
final TextView textViewCN;
if (convertView == null) {
convertView = inflater.inflate(R.layout.single_row_delete_data,
null);
imageViewCheck = (ImageView) convertView
.findViewById(R.id.imageViewSingleRowDeleteData);
textViewCN = (TextView) convertView
.findViewById(R.id.textViewSingleRowDeleteData);
convertView.setTag(new CategoryViewHolder(imageViewCheck,
textViewCN));
}
else {
CategoryViewHolder viewHolder = (CategoryViewHolder) convertView
.getTag();
imageViewCheck = viewHolder.getImageViewCheck();
textViewCN = viewHolder.getTextViewCategoryName();
}
imageViewCheck.setFocusable(false);
imageViewCheck.setFocusableInTouchMode(false);
imageViewCheck.setClickable(true);
imageViewCheck.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
ImageView iv = (ImageView) v;
Category category = (Category) iv.getTag();
if (category.getChecked() == false) {
imageViewCheck.setImageResource(R.drawable.set_check);
listOfItemsToDelete.add(category.getId());
category.setChecked(true);
} else {
imageViewCheck
.setImageResource(R.drawable.set_basecircle);
listOfItemsToDelete.remove((Integer) category.getId());
category.setChecked(false);
}
}
});
imageViewCheck.setTag(category);
if (category.getChecked() == true)
imageViewCheck.setImageResource(R.drawable.set_check);
else
imageViewCheck.setImageResource(R.drawable.set_basecircle);
textViewCN.setText(category.getCatName());
return convertView;
}
}
private void loadDatabase() {
database = openOrCreateDatabase("WalletAppDatabase.db",
SQLiteDatabase.OPEN_READWRITE, null);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
finish();
return true;
}
return super.onKeyDown(keyCode, event);
}
}
如果有任何疑问,可以向我提问...
checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
if(isChecked)
{
ArrayId.add(Yourlist.get(position));//add item position to arraylist if checked
}
else
{
ArrayId.remove(Yourlist.get(position));//remove item position from arraylist if unchecked
}
}
}
然后你遍历存储在arraylist中的每个id并删除该条目。请查看以下代码:
for(int i=0;i<ArrayId.size();i++)
{
Yourlist.remove(ArrayId[i]);
}