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just a quick correction: It's not WinForms that defines partial classes, but the languages of C# and VB do. You don't need a WinForms project to make use of the feature.
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Thanks, Josh !
«Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information?» T. S. Elliot
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When someone starts programming, the first concepts he's learning are "procedural" concepts, i.e. how to control the program flow (if...else, for, do...while etc).
Another concept is "object orientation". Now you have to think of "encapsulation of data" (how to access them, and more important how to change them safely), and eventually of components and their interactions.
Bill mentioned SOLID: those are 5 ways for creating components and having them interact. "S" stands for "single responsibility" and is a good point to start with: a class takes care of one thing only, a function in that class of one action only.
This change in paradigm from mere procedural code to object oriented code is a big step.
Oh sanctissimi Wilhelmus, Theodorus, et Fredericus!
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I have successfully used the InPlaceBitmapMetadataWriter to write Keywords to many photos taken by many cameras, including when I need to extend the metdata padding. However for photos taken by recent cameras the TrySave method always returns false for Keywords. Does anyone know why this might be and how I might solve this?
private bool UpdateMetadataInPlace()
{
bool traySaveSuccessful = false;
string tempPath = PutTogetherTemporaryFilePath();
if (File.Exists(tempPath))
{
File.Delete(tempPath);
}
File.Copy(imageFilePath, tempPath);
using (Stream jpgFileStream = File.Open(tempPath, FileMode.Open, FileAccess.ReadWrite))
{
BitmapDecoder jpgDecoder = BitmapDecoder.Create(jpgFileStream, BitmapCreateOptions.None, BitmapCacheOption.None);
if (jpgDecoder.Frames[0] != null && jpgDecoder.Frames[0].Metadata != null)
{
InPlaceBitmapMetadataWriter metadataJpgWriter = jpgDecoder.Frames[0].CreateInPlaceBitmapMetadataWriter();
metadataJpgWriter.SetQuery("System.Keywords", Keywords.ToArray());
if (metadataJpgWriter.TrySave())
{
traySaveSuccessful = true;
}
}
}
if (traySaveSuccessful == true)
{
File.Delete(imageFilePath);
File.Move(tempPath, imageFilePath);
}
else
{
File.Delete(tempPath);
}
return traySaveSuccessful;
}
modified 29-Oct-18 14:12pm.
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Whenever my application loses focus, the scrolling of a panel is reset to the top position once focus is regained. This is really annoying. I have tried everything I can think of and researched to fix this such as overriding the scroll mechanism and saving coordinates; also doing the same during a mouse wheel scroll and trying to restore with the following method:
private void OnFormActivated(object sender, EventArgs e)
{
panel1.AutoScrollPosition = panelRect.Location;
}
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This works for me: [^].
But, if your Panel is nested inside a Form, or other ContainerControl, with scrolling enabled/visible ... I don't know.
«Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information?» T. S. Elliot
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Let me start out by saying I am a complete noob. I am taking an online only course so asking someone a question is very difficult and often takes days to get a response, so I am trying here.
I am tasked with creating an array that pulled sales from a .txt file. All of the sale amounts in the .txt file have decimal amounts, so I figured I would use a double. I am getting all kinds of errors saying I cannot convert a double to an int. I don't know where in the code I have gone wrong. Again, I am completely new to this and understand I probably have multiple issues. Any help would be greatly appreciated.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace Total_Sales_Homework
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private double Average(double[] iArray)
{
double total = 0.0;
double average;
for (double index = 0; index < iArray.Length; index++)
{
total += iArray[index];
}
average = (double)total / iArray.Length;
return average;
}
private double Highest(double[] iArray)
{
double highest = iArray[0];
for (double index = 1; index < iArray.Length; index++)
{
if (iArray[index] > highest)
{
highest = iArray[index];
}
}
return highest;
}
private double Lowest(double[] iArray)
{
double lowest = iArray[0];
for (double index = 1; index < iArray.Length; index++)
{
if (iArray[index] < lowest)
{
lowest = iArray[index];
}
}
return lowest;
}
private double Total(double[] iArray)
{
double total = iArray[0];
return total;
}
private void salesButton_Click(object sender, EventArgs e)
{
try
{
double totalSales;
double highestSales;
double lowestSales;
double averageSales;
StreamReader inputFile;
const double SIZE = 7;
double[] sales = new double[SIZE];
double index = 0;
inputFile = File.OpenText("Sales.txt");
while (!inputFile.EndOfStream && index < sales.Length)
{
sales[index] = int.Parse(inputFile.ReadLine());
index++;
}
inputFile.Close();
foreach (int value in sales)
{
salesListBox.Items.Add(value);
}
totalSales = Highest(sales);
highestSales = Highest(sales);
lowestSales = Lowest(sales);
averageSales = Average(sales);
totalSalesLabel.Text = totalSales.ToString("n1");
averageSalesLabel.Text = averageSales.ToString("n1");
highestSalesLabel.Text = highestSales.ToString("n1");
smallestSalesLabel.Text = lowestSales.ToString("n1");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
}
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You seem to be mixing double and int types. You should use an int type to set the size of an array. And you should use Double.TryParse on your input values. It would have been more helpful if you showed the exact error message and which line it occurred on.
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Take your errors one-by-one and look at them closely. If you double click on an error message in the "Error List" pane, it will take you to the line it refers to. The first one will be in your Average Method:
private double Average(double[] iArray)
{
double total = 0.0;
double average;
for (double index = 0; index < iArray.Length; index++)
{
total += iArray[index];
}
average = (double)total / iArray.Length;
return average;
}And will say:
Cannot implicitly convert type 'double' to 'int'. An explicit conversion exists (are you missing a cast?)
What that is saying is that you are using a double value where an int is expected, and that the system will not automatically change that for you because it will result in lost information. And that's true: if you convert the double value 1.5 to an int it will "throw away" the half and leave you with 1. The system wants to be sure you meant to do that, so it gives you an error. And array indexes are always either integer or strings, so you can;t use a double between the square brackets.
You can do what it suggests and explicitly cast it:
total += iArray[(int)index]; But that's a poor solution: change the index to an integer and all will be fine:
private double Average(double[] iArray)
{
double total = 0.0;
double average;
for (int index = 0; index < iArray.Length; index++)
{
total += iArray[index];
}
average = total / iArray.Length;
return average;
}The error message will vanish, and you can move on to the next.
Which is the Lowest method, and exactly the same problem!
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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Thanks that makes a lot of sense. I can now get the program to compile, but when I click the button to calculate/display I get a message saying "input string was not in a correct format. I think I found the problem string:
while (!inputFile.EndOfStream && index < sales.Length)
I can't seem to fix it though. Any ideas here? Full code for reference:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace Total_Sales_Homework
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private double Average(int[] iArray)
{
double total = 0.0;
double average;
for (int index = 0; index < iArray.Length; index++)
{
total += iArray[index];
}
average = (double)total / iArray.Length;
return average;
}
private double Highest(int[] iArray)
{
double highest = iArray[0];
for (int index = 1; index < iArray.Length; index++)
{
if (iArray[index] > highest)
{
highest = iArray[index];
}
}
return highest;
}
private double Lowest(int[] iArray)
{
double lowest = iArray[0];
for (int index = 1; index < iArray.Length; index++)
{
if (iArray[index] < lowest)
{
lowest = iArray[index];
}
}
return lowest;
}
private double Total(double[] iArray)
{
double total = iArray[0];
return total;
}
private void salesButton_Click(object sender, EventArgs e)
{
try
{
double totalSales;
double highestSales;
double lowestSales;
double averageSales;
StreamReader inputFile;
const int SIZE = 6;
int[] sales = new int[SIZE];
int index = 0;
inputFile = File.OpenText("Sales.txt");
while (!inputFile.EndOfStream && index < sales.Length)
{
sales[index] = int.Parse(inputFile.ReadLine());
index++;
}
inputFile.Close();
foreach (int value in sales)
{
salesListBox.Items.Add(value);
}
totalSales = Highest(sales);
highestSales = Highest(sales);
lowestSales = Lowest(sales);
averageSales = Average(sales);
totalSalesLabel.Text = totalSales.ToString("n1");
averageSalesLabel.Text = averageSales.ToString("n1");
highestSalesLabel.Text = highestSales.ToString("n1");
smallestSalesLabel.Text = lowestSales.ToString("n1");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
}
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That's the wrong line - it doesn't contain anything that tried to convert a value from a string to anything 
The line just below does though ... it user int.Parse to try and convert a value.
Which implies that you data is not "just numbers", or at least, not "just integer numbers".
We can't look at that - we don't have any access to your data file. And nor do I want it, either - this is an important thing to learn: Compiling does not mean your code is right!
Think of the development process as writing an email: compiling successfully means that you wrote the email in the right language - English, rather than German for example - not that the email contained the message you wanted to send.
So now you enter the second stage of development (in reality it's the fourth or fifth, but you'll come to the earlier stages later): Testing and Debugging.
Start by looking at what it does do, and how that differs from what you wanted. This is important, because it give you information as to why it's doing it. For example, if a program is intended to let the user enter a number and it doubles it and prints the answer, then if the input / output was like this:
Input Expected output Actual output
1 2 1
2 4 4
3 6 9
4 8 16 Then it's fairly obvious that the problem is with the bit which doubles it - it's not adding itself to itself, or multiplying it by 2, it's multiplying it by itself and returning the square of the input.
So with that, you can look at the code and it's obvious that it's somewhere here:
private int Double(int value)
{
return value * value;
}
Once you have an idea what might be going wrong, start using the debugger to find out why. Put a breakpoint on the first line of the method, and run your app. When it reaches the breakpoint, the debugger will stop, and hand control over to you. You can now run your code line-by-line (called "single stepping") and look at (or even change) variable contents as necessary (heck, you can even change the code and try again if you need to).
Think about what each line in the code should do before you execute it, and compare that to what it actually did when you use the "Step over" button to execute each line in turn. Did it do what you expect? If so, move on to the next line.
If not, why not? How does it differ? Look at the variables and see exactly what they contain.
Hopefully, that should help you locate which part of that code has a problem, and what the problem is.
This is a skill, and it's one which is well worth developing as it helps you in the real world as well as in development. And like all skills, it only improves by use!
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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Hello ,
I have this Json :
[
{
"Created_Datetime": "",
"Id": ,
"Last_Login_Datetime": "",
"Leaves": 5,
"Level": 102,
"Losses": 552,
"MasteryLevel": 39,
"Name": "",
"Personal_Status_Message": "",
"Platform": "",
"RankedConquest": {
"Leaves": 0,
"Losses": 21,
"Name": "Conquest",
"Points": 70,
"PrevRank": 0,
"Rank": 0,
"Rank_Stat_Conquest": null,
"Rank_Stat_Duel": null,
"Rank_Stat_Joust": null,
"Season": 2,
"Tier": 15,
"Trend": 0,
"Wins": 14,
"player_id": null,
"ret_msg": null
},
"Region": "Europe",
"TeamId": 0,
"Team_Name": "",
"Tier_Conquest": 15,
"Total_Achievements": 51,
"Total_Worshippers": 91811438,
"Wins": 604,
"ret_msg": null
}
]
And I can't deserialize it entirely with Newtonsoft
What I have tried:
var player1 = JsonConvert.DeserializeObject<IList<Player>>(Json); But all the information in "RankedConquest" are null
I have a class named Player :
public class Player
{
public string Account_Level { get; set; }
public string ChampionName { get; set; }
...
etc
...
public IList<ChampionRanks> m_championslist;
public class RankedConquest
{
public int Leaves { get; set; }
public int Losses { get; set; }
public string Name { get; set; }
public int Points { get; set; }
public int PrevRank { get; set; }
public int Rank { get; set; }
public int Season { get; set; }
public int Tier { get; set; }
public int Trend { get; set; }
public int Wins { get; set; }
public string ret_msg { get; set; }
}
}
}With wich I can do :
Player player1 = JsonConvert.DeserializeObject<Player>(Json.Substring(1, Json.Length - 2));
Same here all the information in "RankedConquest" are null
After this I renamed "public class RankedConquest" to "public class Ranked" and add to my Player class :
public Ranked RankedConquest { get; set; }Then :
player1.RankedConquest = JsonConvert.DeserializeObject<Player.Ranked>(profile);
Give me this error : Cannot deserialize the current JSON array
modified 27-Oct-18 16:37pm.
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I believe the issue lies in that you have multiple fields in Ranked (formerly RankedConquest) marked as type object. I'm pretty sure Newtonsoft doesn't know how to convert from whatever is in the JSON string to the object field, so either specify a class or a value type.
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Thank you, I edited my code but all the data in player1.RankedConquest are still 0 or null
Edit ------------------------------------------------------------------------------------------
Don't know why but all the code work fine now, thank you 
modified 27-Oct-18 16:37pm.
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very odd. if you come up with the reason why, i'd be curious.
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Complete Programming Problem #1, Distance Calculator, on page 337 of the textbook.
(using the "starting out with Visual C#" 4th edition Author tony Gaddis, and using visual studios 2015)
The ADDITIONAL REQUIREMENTS described below MUST also be implemented:
Assume the value of Vehicle Speed in MPH may store whole or floating-point numbers (non-monetary).
Assume the value of Hours Traveled can only store whole numbers.
Prevent data conversion exception for the Vehicle Speed in MPH text box by using the appropriate TryParse method. If the data entered is invalid display an appropriate error message to the user, set the focus back to the text box causing the error, and either clear the text box or select all the data entered into it so that it can be replaced.
Validate the input for the Vehicle Speed in MPH to make sure the data entered is greater than zero and does not exceed 180. If not, display an appropriate error message to the user, set the focus back to the text box causing the error, and either clear the text box or select all the data entered into it so that it can be replaced.
Prevent data conversion exception for the Hours Traveled text box by using the appropriate TryParse method. If the data entered is invalid display an appropriate error message to the user, set the focus back to the text box causing the error, and either clear the text box or select all the data entered into it so that it can be replaced.
Validate the input for Hours Traveled to make sure the data entered is greater than zero and not more than 50. If not, display an appropriate error message to the user, set the focus back to the text box causing the error, and either clear the text box or select all the data entered into it so that it can be replaced.
Implement the following fields:
Total Distance which accumulates the distance for each entry (i.e., as shown in the ListBox control)
Total Hours Traveled which accumulates the hours traveled for each entry (i.e., as entered in the Hours Traveled TextBox control)
Total Trips which counts each entry (i.e., incremented each time the user clicks the Calculate Button control)
Display appropriate output to the ListBox control as shown in the sample input-output document attached.
Display Total Distance as a number with two-decimal places.
Display Total Hours Traveled and Total Trips as a number with no decimal places.
Calculate and display the Average Distance which is the Total Distance divided by the Total Trips (recall, average distance is not an accumulator or counter) formatted as a number with two-decimal places.
The program MUST include standard features of a Windows application including:
Change the default Text property of the form to something descriptive
Appropriate naming conventions for all controls (i.e., buttons, labels, text boxes, list). The standard naming convention is descriptive name including control type using camelCase notation. For example: hoursTraveledTextBox, distanceListBox, totalHoursTraveledLabel, exitButton. The exception is controls not referenced in the code-behind of Form1. For example, Label controls used for descriptive purposes only or PictureBox controls used for aesthetic purposes only.
Calculate, Clear, and Exit buttons with appropriate name and keyboard access key
AcceptButton and CancelButton properties should be appropriately assigned to the Calculate button and Clear button, respectively
Ensure tab order for form is logical
When Clear button is clicked the controls outside of the Summary GroupBox control should be cleared (i.e. using the Clear method or assigning an empty string) and the focus set back to the first TextBox control for entering data. The controls inside the Summary GroupBox control should NOT be cleared (i.e., using the Clear method or assigning an empty string). Do NOT reset the values of the fields to zero.
Appropriate naming conventions and data type declarations for variables and fields.
Remove all unused event handlers from the program code.
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Carefully.
Next!
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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C#NoobHelpMe wrote: on page 337 of the textbook
Start there.
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Who needs to read textbooks when CodeProject is free?
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Nobody who uses four question marks together is allowed to read a text book. It's probably a law, like "you can't put anything interesting on TV on a Saturday".
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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People have been making an assumption (very probably valid) that you want us to write your code for you. That would be doing you a disservice though as the question you ask is "How do I do this assignment????" and that's the question I'm going to answer, even though it's probably not the answer that you were wanting.
What you have here are a set of requirements. Some are explicitly stated and some require you to apply a little bit of problem solving. You start your task by working out what you already know. For instance, you have a vehicle speed and you know that it can store whole or floating point numbers (non-monetary). With a little bit of thought, you realise that the speed property is not going to be a whole number so it can't be a long, short or an int. This doesn't leave you with much in the way of data types so you need to do a little bit of research and find out which data types are available in C# that aren't monetary either.
That's how you solve the problem. By breaking big problems down into little problems. You have all the information you need in this question and the related book, so make use of them.
This space for rent
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Pete O'Hanlon wrote: What you have here are a set of requirements
Requirement rarely come in that form, unless we are reverse-engineering. What he has is an exact specification of the properties for the components that the teach desires.
Student does not need knowledge on why those properties exist, or why it would be preferred over the alternative. It is not an assignment, it's a joke.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.
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Hi experts,
I have a WinForm app, with form that build Background Workers in code.
The trigger is a local timer which kill the current BGW if he finished and create it again.
I need in this specific time (between the kill and create - clear all the resources (mainly - memory).
The app uploading files (each above 100MB) using Arrays & Memory Streams.
without clear the memory - it grows with each file ( 3 files can easily get above 1G)
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There are problems here.
1) If you kill a task, it's dead. It can't be asked to recycle it;s resourced after you kill it as the thread itself is terminated, which automatically recycles the stack. So you have no access to the variables that thread was using! To recycle, you need to tell the thread itself it's not needed and let it handle disposal as necessary before it terminates itself by returning from its startup method.
2) There is no specific Array.Dispose in .NET - which means you have no direct control over when the memory allocated to an array is released, even if you are in the task that created it.
The only way to do this is clumsy: tell the task to die via a semaphore so it can intelligently release what resources it has acquired; then when it is complete call GC.Collect to reclaim all unused memory.
Do note that this will not reduce the memory footprint of your overall application, as memory once allocated to a process is not released back to the OS once it is recycled by the CG.
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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