我想知道如何做到这一点。
我在活动 A 中有一个listView。当检测到长按时，它会checkMaxID(ID,iD);。如果iD为最大值，则将显示success，删除列表，最后刷新列表。否则，它将显示list cannot be deleted并且不会通过objadapter.removeItem(po);。
现在我想要实现的是调用
objadapter.removeItem(po);仅当列表被删除时。如果没有，
objadapter.removeItem(po);不会被召唤。
listViewUpdate.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
public boolean onItemLongClick(final AdapterView<?> p, View v, final int po, long id) {
iD = details1.get(po).getID();
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Delete");
builder.setMessage("Are you sure you want to delete?");
builder.setIcon(android.R.drawable.ic_dialog_alert);
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int ii) {
checkMaxID(ID,iD);
objadapter.removeItem(po); // only call when list get deleted
RetrieveTotalHours(ID);
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int ii) {
dialog.dismiss();
}
}
);
builder.show();
return true;
}
});
public void checkMaxID(final int foreignKey,final String iD)
{
class check extends AsyncTask<Void,Void,String>{
// ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
// loading = ProgressDialog.show(Edit_Staff.this,"Updating...","Wait...",false,false);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
// loading.dismiss();
Toast.makeText(getActivity(), s, Toast.LENGTH_LONG).show();
}
@Override
protected String doInBackground(Void... params) {
HashMap<String,String> hashMap = new HashMap<>();
hashMap.put(Configs.KEY_ID, iD);
hashMap.put(Configs.KEY_TWD, String.valueOf(foreignKey));
RequestHandler rh = new RequestHandler();
String s = rh.sendPostRequest(Configs.URL_CHECK_ID, hashMap);
return s;
}
}
check ue = new check();
ue.execute();
}
检查 ID.php
<?php
if(isset($_POST['id'], $_POST['twd'])){
/*Importing our db connection script*/
require_once('dbConnect.php');
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s'n", mysqli_connect_error());
exit();
}
$id = mysqli_real_escape_string($con, $_POST['id']);
$twd = mysqli_real_escape_string($con, $_POST['twd']);
$sql ="SELECT MAX(id) as MaxId FROM work_details WHERE twd = '$twd'";
if ($result = mysqli_query($con, $sql)) {
/* fetch associative array */
if ($row = mysqli_fetch_row($result)) {
if($row[0] === $id){
$sql ="DELETE FROM work_details WHERE id='$id';";
if ($result = mysqli_query($con, $sql)) {
echo 'success';
}else{
echo 'failed';
}
}
else{
echo 'list cannot be deleted ';
}
}
/* free result set */
}
/* close connection */
mysqli_close($con);
}
?>
你需要在你的PHP脚本中添加一些json：
<?php
$json = array();
if(isset($_POST['id'], $_POST['twd'])){
/*Importing our db connection script*/
require_once('dbConnect.php');
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s'n", mysqli_connect_error());
exit();
}
$id = mysqli_real_escape_string($con, $_POST['id']);
$twd = mysqli_real_escape_string($con, $_POST['twd']);
$sql ="SELECT MAX(id) as MaxId FROM work_details WHERE twd = '$twd'";
if ($result = mysqli_query($con, $sql)) {
/* fetch associative array */
if ($row = mysqli_fetch_row($result)) {
if($row[0] === $id){
$sql ="DELETE FROM work_details WHERE id='$id';";
if ($result = mysqli_query($con, $sql)) {
echo 'success';
$json['success'] = true;
$json['message'] = 'delete is successful';
}else{
$json['success'] = false;
$json['message'] = 'list cannot be deleted';
}
}else{
$json['success'] = false;
$json['message'] = '($row[0] !== $id)';
}
} else{
$json['success'] = false;
$json['message'] = 'select is unsuccessful';
}
/* close connection */
mysqli_close($con);
}
}
?>
在你的Java中解析它：
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
Toast.makeText(getActivity(), s, Toast.LENGTH_LONG).show();
try{
JSONObject json = new JSONObject(s);
if(json.getBoolean("success")){
objadapter.removeItem(po)
}else{
Toast.makeText(getActivity(),
json.getString("message"),
Toast.LENGTH_LONG).show();
}
}catch(JSONException ex){
}
}