C# lists and datagridviews - c#

I'm trying to populate a datagrid with info out of a list, and then after pressing a save button it saves the datagrid changes back into the list.
int pos = MainMenu.myList.FindIndex(x => x.ID == validID);
var tempStu = MainMenu.myList[pos];
if (tempStu is DormStudent)
{
DormStudent tempDorm = tempStu as DormStudent;
nameTextBox.Text = tempDorm.Name;
var blist = new BindingList<Student>(tempDorm.Grades);
var source = new BindingSource(blist, null);
gradesDataGridView.DataSource = source;
}
else
{
nameTextBox.Text = tempStu.Name;
var blist = new BindingList<Student>(tempStu.Grades);
var source = new BindingSource(blist, null);
gradesDataGridView.DataSource = source;
}
and when you push the save button (i don't have the save part as nice)
int pos = MainMenu.myList.FindIndex(x => x.ID == validID);
var tempStu = MainMenu.myList[pos];
if (tempStu is DormStudent)
{
DormStudent tempDorm = tempStu as DormStudent;
tempDorm.Grades = gradesDataGridView;
MainMenu.myList[pos] = tempDorm;
}
else
{
tempStu.Grades = gradesDataGridView;
MainMenu.myList[pos] = tempStu;
}
here's the Student class that the grades is in.
public class Student
{
public int ID { get; set; }
public string Name { get; set; }
public List<int> Grades;
public Student()
{
ID = 0;
Name = "No Student";
Grades = new List<int>();
}
public Student(int i, string n)
{
ID = i;
Name = n;
Grades = new List<int>();
}
}
I can't get either the converting the list to the datagrid when the check button is pressed or back when the save button is pressed. can anyone help with that?

Looking at your code I see mainly one issue. Note, however, that I am far from being an expert in Data Binding!
I see that you are creating a BindingList<> for type Student. I hope you actually want to display one Student's grades top down.
If instead you really wanted to display all Students top down and their grades in the columns from left to right you would have to do some serious twisting!
Now the BindingList should bind the Grades not a Student, so the first idea would be to change it to BindingList<int>.
However afaik unnamed variables make bad DataMembers. To display them the data should be Properties.
So I created a new class Grade that wraps the integer. For good measure I also added a string Test to hold a description of the the test. Leave it out if you don't want it!
public class Grade
{
public int Points { get; set; }
public string Test { get; set; }
public Grade()
{ Points = 0; Test = "No Test"; }
public Grade(int points, string test)
{ Points = points; Test = test; }
}
This calls for changes in the Student class:
public List<Grade> Grades;
and (twice)
Grades = new List<Grade>();
The two lines creating the BindingList now look like this:
var blist = new BindingList<Grade>(tempDorm.Grades);
var blist = new BindingList<Grade>(tempStu.Grades);
The good news is that not only the data now load fine into the DataGridView; there is also no need at all for the save action, as the Data are bound two-way and every change actually happens in the List!
Only in the event of needing an undo function will you need some more coding, but that is another matter..

Related

Problem in databinding Array data to DataGridView in c#

I have been binding short data to DataGridView in C# Winforms. However, I need to bind long string array with size 75 to DataGridView. My data list class consists of 6 individual variables with get and set and array of string which I have defined get and set properties. The individual variables are displayed but the array of strings is not displayed in DataGridView. In debug, I checked the data source of DataGridView and it seems ok. How can I display binded array in gridview.
Below is my source code to populate DataGridView named Logview
public void populateLogData(string path)
{
StreamReader sr = null;
BindingList<LogList> bindLogList;
BindingSource bLogsource = new BindingSource();
List<LogList> loglist = new List<LogList>();
try
{
Logview.DataSource = null;
Logview.Rows.Clear();
Logview.Columns.Clear();
Logview.AutoGenerateColumns = true;
if (File.Exists(path))
{
try
{
sr = new StreamReader(path);
StringBuilder readline = new StringBuilder(sr.ReadLine());
if (readline.ToString() != null && readline.ToString() != "")
{
readline = new StringBuilder(sr.ReadLine());
while (readline.ToString() != null && readline.ToString() != "")
{
string[] subdata = readline.ToString().Split(',');
LogList tloglist = new LogList(subdata[0], subdata[1], subdata[2], subdata[3], subdata[4], subdata[5], max_index);
for (int i = 6; i < subdata.Length; i++)
tloglist.setPartList(i-6, subdata[i]);
loglist.Add(new LogList(subdata, subdata.Length));
readline = new StringBuilder(sr.ReadLine());
}
}
bindLogList = new BindingList<LogList>(loglist);
bLogsource.DataSource = bindLogList;
Logview.AutoGenerateColumns = true;
Logview.DataSource = bindLogList;
Logview.Columns[0].Width = 140; // project name
Logview.Columns[1].Width = 140; // data/time
Logview.Columns[2].Width = 90;
Logview.Columns[3].Width = 90;
Logview.Columns[4].Width = 90;
Logview.Columns[5].Width = 90;
// max_index is set from another part of code
for(int i = 0; i <= max_index; i++)
{
int counter = 6 + i;
Logview.Columns.Add(headertext[i], headertext[i]);
Logview.Columns[counter].Width = 90;
Logview.Columns[counter].HeaderText = headertext[i];
}
}
catch (IOException io)
{
MessageBox.Show("Error: Cannot Open log file.");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
if (sr != null) sr.Close();
}
}
else
{
MessageBox.Show("Log file not found \n" + path);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
GC.Collect();
}
}
Below is LogList class
class LogList
{
const int max_size = 100;
private string[] holdList;
public string project { get; set; }
public string date_time { get; set; }
public string Qty { get; set; }
public string Pass { get; set; }
public string Fail { get; set; }
public string Result { get; set; }
public string[] partlist
{
get
{
return holdList;
}
set
{
holdList = value;
}
}
public LogList(string project, string date_time, string Qty, string Pass, string Fail, string Result, int partsize)
{
this.project = project;
this.date_time = date_time;
this.Qty = Qty;
this.Pass = Pass;
this.Fail = Fail;
this.Result = Result;
partlist = new string[partsize+1];
}
public void setPartList(int size, string getValue)
{
partlist[size] = getValue;
}
}
Project, date/time, Qty, Pass, Fail, Result is displayed. But partlist array is not displayed.
To supplement IVSoftware’s answer, below is an example using two grids in a master-detail scenario.
One issue I would have with your current approach, is that it uses an Array for the “parts list.” Currently this is a string array, and that isn’t going to work if we want to display it in a grid. Fortunately, there are a few easy ways we can get the data to display as we want.
One simple solution is to create a “wrapper” Class for the string. I will call this Class Part. I added a simple int ID property and the string PartName property. You could easily leave out the ID and have a simple string wrapper. This simple Class may look something like…
public class Part {
public int ID { get; set; }
public string PartName { get; set; }
}
This should allow the data to display correctly in the grid using just about any construct like an array, list etc.… So, we “could” change your current code to use an array of Part objects like…
Part[] Parts = new Parts[X];
And this would work, however, if we use an array and we know for sure that each LogItem may have a different number of parts in its PartsList, then we will have to manage the array sizes. So, a BindingList of Part objects will simplify this. The altered LogList (LogItem) Class is below…
public class LogItem {
public BindingList<Part> PartsList { get; set; }
public string Project { get; set; }
public string Date_Time { get; set; }
public string Qty { get; set; }
public string Pass { get; set; }
public string Fail { get; set; }
public string Result { get; set; }
public LogItem(string project, string date_Time, string qty, string pass, string fail, string result) {
Project = project;
Date_Time = date_Time;
Qty = qty;
Pass = pass;
Fail = fail;
Result = result;
PartsList = new BindingList<Part>();
}
}
So given the updated Classes, this should simplify things and we will use the same DataSource for both grids. This DataSource for the “master” grid will be a BindingList of LogItem objects. In the “detail” grid, we simply need to point it’s DataMember property to the PartsList property of the currently selected LogItem. And this would look something like…
dgvLogs.DataSource = LogsBL;
if (LogsBL.Count > 0) {
dgvParts.DataMember = "PartsList";
dgvParts.DataSource = LogsBL;
}
Below is the code to test the Classes above in a master-detail scenario with two grids. Create a new winform solution and drop two (2) DataGridViews on the form. The grid on the left is dgvLogs and the grid on the right is dgvParts.
public void populateLogData(string path) {
BindingList<LogItem> LogsBL = new BindingList<LogItem>();
string currentLine;
if (File.Exists(path)) {
try {
using (StreamReader sr = new StreamReader(path)) {
LogItem tempLogItem;
currentLine = sr.ReadLine(); // <- header row - ignoring
currentLine = sr.ReadLine();
while (currentLine != null) {
if (!string.IsNullOrEmpty(currentLine)) {
string[] splitArray = currentLine.Split(',');
if (splitArray.Length >= 6) {
tempLogItem = new LogItem(splitArray[0], splitArray[1], splitArray[2], splitArray[3], splitArray[4], splitArray[5]);
for (int i = 6; i < splitArray.Length; i++) {
tempLogItem.PartsList.Add(new Part { ID = i, PartName = splitArray[i] });
}
LogsBL.Add(tempLogItem);
}
else {
Debug.WriteLine("DataRead Error: Not enough items to make a LogItem: " + currentLine);
}
}
else {
Debug.WriteLine("DataRead Empty row");
}
currentLine = sr.ReadLine();
}
}
dgvLogs.DataSource = LogsBL;
if (LogsBL.Count > 0) {
dgvParts.DataMember = "PartsList";
dgvParts.DataSource = LogsBL;
}
}
catch (IOException io) {
MessageBox.Show("Error: Cannot Open log file.");
}
catch (Exception ex) {
MessageBox.Show(ex.Message + " Stacktrace- " + ex.StackTrace);
}
}
else {
MessageBox.Show("Log file not found \n" + path);
}
}
And some test data…
H1,h2,h3,h4,h5,h6,h7,h8
Model: LMG600N_IF_2blablas,2022-9-6,112,61,51,Fail,p1,p3,p4,p5,p6
1,2022-9-6,2112,621,251,Pass,px4,px5,px6,px1,px2,px3
data1,2022-9-7,3456,789,123,Fail,z3,z3,z4
Model: LMG600N_IF_2blablas,2022-9-6,112,61,51,Fail
Model: LMG600N_IF_2blablas,2022-9-6,112,61,51,Fail,p1,p3,p4,p5,p6,p7,p8,p99
BadData Model: LMG600N_IF_2blablas,2022-9-6,112,61
Moxxxdel: LMG600N_IF_2blablas,2022-9-6,11x2,6x1,5x1,Fail
Hope this helps and makes sense.
Your data list class consists of 6 individual variables with get and set, and an array of string. Your question is about the variables are displayed but the array of strings is not.
Here's what has worked for me (similar to the excellent suggestion by JohnG) for displaying the string array. What I'm doing here is taking a DataGridView and dropping in my main form without changing any settings (other than to Dock it). Given the default settings, the LogList class (shown here in a minimal reproducible example of 1 variable and 1 array of strings) is defined with a public string property named PartList and with this basic implementation:
class LogList
{
public LogList(string product, string[] partList)
{
Product = product;
_partList = partList;
}
public string Product { get; set; }
private string[] _partList;
public string PartList => string.Join(",", _partList);
}
To autoconfigure the DataGridView with Product and PartList columns, here is an example initializer method that sets the DataSource and adds the first three items as a test:
// Set data source property once. Clear it, Add to it, but no reason to nullify it.
BindingList<LogList> DataSource { get; } = new BindingList<LogList>();
private void InitDataGridView()
{
dataGridView1.DataSource = DataSource;
// Auto config columns by adding at least one Record.
DataSource.Add(
new LogList(
product: "LMG450",
// Four parts
partList: new string[]
{
"PCT2000",
"WCT100",
"ZEL-0812LN",
"EN61000-3-3/-11",
}
));
DataSource.Add(
new LogList(
product: "LMG600N",
// Three parts
partList: new string[]
{
"LTC2280",
"BMS6815",
"ZEL-0812LN",
}
));
DataSource.Add(
new LogList(
product: "Long Array",
// 75 parts
partList: Enumerable.Range(1, 75).Select(x => $"{ x }").ToArray()
));
// Use string indexer to access columns for formatting purposes.
dataGridView1
.Columns[nameof(LogList.Product)]
.AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
dataGridView1
.Columns[nameof(LogList.PartList)]
.AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;
}
After running this code, the DGV looks like this:
With the mouse hovered over the item all 75 "parts" can be viewed.
One last thing - I notice you have some methods to assign a new partList[] of perhaps change an individual part at a specified index. (I didn't show them in the minimal sample but for sure you'll want things like that). You probably know this but make sure to call dataGridView1.Refresh after altering properties of an existing row/LogList object so that the view will reflect the changes.
I hope there's something here that offers a few ideas to achieve the outcome you want.

Problem while updating a child list in C # ASP.Net MVC

public class PayRateDaysModel
{
public string day_name { get; set; }
public List<RateList> multiplier { get; set; }
}
public class RateList
{
public double start_after { get; set; }
public double rate_multiplier { get; set; }
}
daysModel is a List of type PayRateDaysModel. When I'm trying to update multiplier in current object of daysModel list i.e. dayExists, then its updating multiplier in all the elements of daysModel list. I want to update only in current item.
Below is my code :
var dayExists = daysModel.Where(x => x.day_name == day_name).FirstOrDefault();
if(dayExists==null)
{
PayRateDaysModel days = new PayRateDaysModel();
days.day_name = day_name;
days.multiplier = rate_list;
daysModel.Add(days);
}
else
{
//update
dayExists.day_name = "abc";
dayExists.multiplier.FirstOrDefault().rate_multiplier = 1;
}
Based on what you have shown to us I would think that you are creating the rate_list somewhere above like rate_list = new RateList(…) and you are setting this to all of your days in days.multiplier = rate_list;. Since you did not recreate that rate_list for every element, any time you change it in one of your dayExists you will change it for all the others as well. So you should do something like this days.multiplier = new RateList(…);
Check this link : Updating child items in List updates all Items in C#
I don't see any reason for it not to work. Are you sure you are testing it in right way?
I think it will be better to improve the code and test for null value :
var dayExists = daysModel.Where(x => x.day_name == day_name).FirstOrDefault();
if(dayExists==null)
{
PayRateDaysModel days = new PayRateDaysModel();
days.day_name = day_name;
days.multiplier = rate_list;
daysModel.Add(days);
}
else
{
//update
dayExists.day_name = "abc";
var firstMultiplier= dayExists.multiplier.FirstOrDefault();
if( firstMultiplier!=null)
{
firstMultiplier.rate_multiplier = 1;
}
}

c# how to decide whether to add to sub-list or start new one

I have an sql query that provides me my data where I sometimes have lines that should be clustered (the data is aligned with an order by). The data is grouped by the field CAPName. Going through those rows line by line, I need to decide whether a new list should be initiated (content of CAPName differs to previous itteration), or whether the (already) initated list (from the previous iteration) should be added, too.
My pain lays with the location of the declaration of the relatedCapabilitySystem list.
I wanted to declare it within the if statement (Because, as I stated I need to decide whether the list from the previous iteration should be added too, or whether it should start a new list), but I can't as the compiler throws an exception, as the RLCapSys.Add(rCs); is non-existing in this content (which is only theoretically true). I understand why the compiler throws this exception. But if I declare the list on a "higher" level, than I always have a new list, which I don't want in the case that the item should be added to the list defined in the iteration(s) (1 or more) before
So what I want to achieve is, generate the list RLCapSys and add to it, in case the previous iteration contains the same CAPName (for clustering), otherwise create a new list.
SqlCommand cmdDetail = new SqlCommand(SQL_SubSytemsToCapability, DBConDetail);
SqlDataReader rdrDetail = cmdDetail.ExecuteReader();
List<relatedCapility> RLCaps = new List<relatedCapility>();
string lastCapShown = null;
while (rdrDetail.Read())
{
List<relatedCapabilitySystem> RLCapSys = new List<relatedCapabilitySystem>();
if (lastCapShown != rdrDetail["CAPName"].ToString())
{
//List<relatedCapabilitySystem> RLCapSys2 = new List<relatedCapabilitySystem>();
relatedCapility rC = new relatedCapility
{
Capability = rdrDetail["CAPName"].ToString(),
systemsRelated = RLCapSys,
};
RLCaps.Add(rC);
}
relatedCapabilitySystem rCs = new relatedCapabilitySystem
{
system = rdrDetail["name"].ToString(),
start = rdrDetail["SysStart"].ToString(),
end = rdrDetail["SysEnd"].ToString(),
};
RLCapSys.Add(rCs);
// method to compare the last related Capability shown create a new related Capabilty entry or add to the existing releated Capabilty related system list
lastCapShown = rdrDetail["CAPName"].ToString();
}
DBConDetail.Close();
and for reason of completness (but I think it is not needed here):
internal class CapabilitiesC
{
public List<Capability>Capabilities{ get;set;}
}
public class Capability
{
public string name { get; internal set; }
public string tower { get; internal set; }
public string color { get; internal set; }
public List<relatedCapility> related { get; set; }
}
public class relatedCapility
{
public string Capability { get; set; }
public List<relatedCapabilitySystem> systemsRelated { get; set; }
}
public class relatedCapabilitySystem
{
public string system { get; set; }
public string start { get; set; }
public string end { get; set; }
}
The purpose of your code is to take the input data and group it by capability. However, that is not immediately obvious. You can change your code to use LINQ so it becomes easier to understand and in the process solving your problem.
First you need a type to represent a record in your database. For lack of better name I will use Record:
class Record
{
public string System { get; set; }
public string Start { get; set; }
public string End { get; set; }
public string Capabilty { get; set; }
}
You can then create an iterator block to return all the records from the database (using an OR mapper like Entity Framework avoids most of this code and you can even shift some of the work from your computer to the database server):
IEnumerable<Record> GetRecords()
{
// Code to create connection and command (preferably in a using statement)
SqlDataReader rdrDetail = cmdDetail.ExecuteReader();
while (rdrDetail.Read())
{
yield return new Record {
System = rdrDetail["name"].ToString(),
Start = rdrDetail["SysStart"].ToString(),
End = rdrDetail["SysEnd"].ToString(),
Capability = rdrDetail["CAPName"].ToString()
};
}
// Close connection (proper using statement will do this)
}
Finally, you can use LINQ to perform the grouping:
var RLCaps = GetRecords()
.GroupBy(
record => record.Capability,
(capability, records) => new relatedCapility
{
Capability = capability ,
systemsRelated = records
.Select(record => new relatedCapabilitySystem
{
system = record.System,
start = record.Start,
end = record.End
})
.ToList()
})
.ToList();
Why not just assign it as NULL. The pattern would be
List<> myList = null;
if(condition)
{
myList = new List<>();
}
else
{
myList = previousList;
}
myList.Add();
previousList = myList;
I've got it working now. Thx everyone for your help. #martin, thx for your solution, you have put quite some effort into this, but that would have required for me to completely re-write my code. I am sure your approach would work and will be my next approach should I have a similar problem again.
It was a combination of the other answers that helped me figure it out. Let me show you what I ended up with:
SqlCommand cmdDetail = new SqlCommand(SQL_SubSytemsToCapability, DBConDetail);
SqlDataReader rdrDetail = cmdDetail.ExecuteReader();
List<relatedCapility> RLCaps = new List<relatedCapility>();
List<relatedCapabilitySystem> RLCapSys = new List<relatedCapabilitySystem>();
string lastCapShown = null;
while (rdrDetail.Read())
{
if (lastCapShown != rdrDetail["CAPName"].ToString())
{
RLCapSys = relatedCapabilitySystemList();
relatedCapility rC = new relatedCapility
{
Capability = rdrDetail["CAPName"].ToString(),
systemsRelated = RLCapSys,
};
RLCaps.Add(rC);
}
relatedCapabilitySystem rCs = new relatedCapabilitySystem
{
system = rdrDetail["name"].ToString(),
start = rdrDetail["SysStart"].ToString(),
end = rdrDetail["SysEnd"].ToString(),
};
RLCapSys.Add(rCs);
// method to compare the last related Capability shown create a new related Capabilty entry or add to the existing releated Capabilty related system list
lastCapShown = rdrDetail["CAPName"].ToString();
}
DBConDetail.Close();
So that's the section already shown bevor including my changes. Plus I added this:
private List<relatedCapabilitySystem> relatedCapabilitySystemList()
{
List<relatedCapabilitySystem> RLCapSys = new List<relatedCapabilitySystem>();
return RLCapSys;
}
Now I have new list reference everytime the CapName changes that is then added to the "higher" list. Before I had the issue of the very same list repeatedly assigned rather than a fresh one started. So thx again for your effort.

Generate checkboxes in or selectable buttons in WPF from database

I am new to C# and need a little bit of help. I want to import a table with three columns from a csv(semicolon separated) database. Then I want to go through all rows of the table, get all the rows with a "value" and then make checkboxes or multi-selectable buttons of some sort appear depending on "value". I am not sure how to do this, so I have just started with trying to import the data from the database. Here is the code I have:
class Nettstasjoner
{
public string NS { get; set; }
public string Sek { get; set; }
public string Radial { get; set; }
public string Value { get; set; }
Value = "H812"; //this will be set from a button later
static void Main(string[] args)
{
IEnumerable<string> strCSV =
File.ReadLines(#"C:\Users\thomoe\Desktop\SMSvarsel\nsdatabase.csv");
var results = from str in strCSV
let tmp = str.Split(';')
select new
{
NS = tmp[0],
Sek = tmp[1],
Radial = tmp[2]
};
foreach (var tmp in results)
{
//here I need to select all rows with the Value value in it and make a checkbox or something with the captin from the row NS(tmp[0]).
}
}
}
I am very open to other ways of doing this, including MVVM, I have just tried to do what I can with googling and so on. Now I am stuck though. Thank you so much for helping and please be very specific when answering ;) My understanding of C# is still very slim :)
You are already have a collection of data.
First, make your collection more "object-like" by explicit class decloration:
public class MyModel
{
public string NS { get; set; }
public string Sek { get; set; }
public string Radial { get; set; }
}
and change your code to
select new MyModel
{
NS = tmp[0],
Sek = tmp[1],
Radial = tmp[2]
};
Next you need to use one of item containers in your view, for example ListBox or https://msdn.microsoft.com/en-us/library/system.windows.controls.listview(v=vs.110).aspx with your custom template which will show an checkbox and anything else for your model class.
Finally you need to bind your collection from ViewModel to the ListView by using binding.
It's not completed solution but I hope it'll help you to understand the main principle.
You have to use TextFieldParser
TextFieldParser parser = new TextFieldParser(#"C:\Users\thomoe\Desktop\SMSvarsel\nsdatabase.csv");
parser.TextFieldType = FieldType.Delimited;
parser.SetDelimiters(";");
List<MyStruct> myData = new List<MysTruct>();
while (!parser.EndOfData)
{
//Process row
string[] fields = parser.ReadFields();
myData.Add(new MyStruct()
{
NS = fields[0],
Sek = fields[1],
Radial = fields[2]
});
}
now you will have the list of your data objects;
You can do it in many way, but I would do it like this:
creating your own control like subwindow, in that control you will have one grid where you will create rows and columns as you want and placing there your button/checkbox etc. with your params, or of course create just some grid on your window and making it in window.cs

C# List - Sorting Data

I am trying to add elements into a list, order them and then output them, there a number of "columns" if you like, per list
List<Info> infoList = new List<Info>();
while (dr.Read())
{
meeting_id = dr.GetValue(0).ToString();
try
{
Appointment appointment = Appointment.Bind(service, new ItemId(meeting_id));
Info data = new Info();
data.Start = appointment.Start;
data.Fruit = Convert.ToInt32(dr.GetValue(1));
data.Nuts = Convert.ToInt32(dr.GetValue(2));
infoList.Add(data);
}
Then to output it I want to order it by Start and then display all associated columns
for (int i = 0; i < infoList.Count; i++)
{
meet = meet + infoList[i];
}
First question: is the way I am inputting the data right?
Second question: How to I output all the columns to display all the associated columns? Is this possible? Is there a better practice?
Thanks
EDIT:
The class if you are interested:
public class Info
{
public DateTime Start { get; set; }
public int Fruit { get; set; }
public int Nuts { get; set; }
}
You can use Enumerable.OrderBy extension for enumerating your collection in some particular order (e.g. ordered by Start property value):
foreach(var info in infoList.OrderBy(i => i.Start))
{
// use info object here
// info.Fruits
// info.Nuts
}
BTW consider to add sorting on database side - that will be more efficient

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