I have a silly error I can't get shot of.
I'm using a string to check the name of folders and their extension types. I'm doing this so I can navigate between folders. This works fine with my first folder selection, however, when I try and click on a second one I get null reference exception.
This is what I have at the moment.
string clickObject = listBox1.SelectedItem.ToString();
int index = clickObject .LastIndexOf('.');
string extension = clickObject .Substring(index + 1, clickObject .Length - index - 1);
if (extension == "folder")
{
// do stuff
}
After this I simply check the files in my folder.
When I go back to the root of my searchable folder and click on another directory, that is when i get the error and the line string clickObject = listBox1.SelectedItem.ToString(); is highlighted.
At the end of my method where I set this I tried setting clickedObject = null; I tried to remove the string that was contained with clickObject.Remove(0); but the error still persists.
How can I clear the information held in clickedObject so I can overwrite it with new information?
Edit
Sorry forgot to mention when I go back to the root I have a button that calls this method:
using (var client = new WebClient())
{
result = client.DownloadString("http://foo.foo.com/images/getDirectoryList.php");
}
string[] names = result.Split('|');
listBox1.Items.Clear();
foreach (string name in names)
{
listBox1.Items.Add(name);
}
listBox1.Update();
listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
However, when I click an item in the list box, its the first set of code that gets used and that is in a sepearate method.
If you are handling the SelectedIndexChanged event you need to cope with it being null as there are cases where it won't be set.
Therefore in your handler you must check that listBox1.SelectedItem is not null before trying to convert it to a string:
if (listBox1.SelectedItem != null)
{
// Your code
}
Not sure if this is a bug.. but I too have come across this before.
The problem is, that SelectedItem isn't always available during the SelectedIndexChanged event.. or sometimes not at all.
The fix is to access the item directly:
string clickObject = listBox1.Items[listBox1.SelectedIndex].ToString();
Also, while you're there.. you can use File.GetExtension method in System.IO to get the extension (instead of doing it yourself):
using System.IO;
string extension = File.GetExtension(clickObject);
Related
I am trying to search through a folder with Event Logs in them, eventpath has the path of the specific Event Log I want to access. I want to use a specified RecordID to find it's correlated FormatDescription and display it in a MessageBox. I want to be able to use the eventpath to access each Event Log since I am using 6 separate .evtx files and need to use this method on all of them.
I found this solution, but I get an error when I'm trying to Query. I've tried to find a fix, but it seems as if it's just not going to work for what I need. I commented where exactly it is occurring in the code.
This is the exception: System.Diagnostics.Eventing.Reader.EventLogException: The specified path is invalid.
I can't find a fix for this code, but if anyone knows a fix or another way to approach searching through Event Logs by RecordID and giving the corresponding FormatDescription, it would be greatly appreciated.
I am using C# in Windows Presentation Foundation.
public void getDesc(string recordid)
{
string eventpath = getEventPath();
//takes off the .evtx of the path
string result = eventpath.Substring(0, eventpath.Length - 5);
//result1 is going to be similar to this:
//C:\Users\MyName\AppData\Local\Temp\randomTempDirectory\additional_files\DiagnosticInfo\WindowsEventLogs\Application
string sQuery = "*[System/EventRecordID=" + recordid + "]";
var elQuery = new EventLogQuery(result, PathType.LogName, sQuery);
//this is where it errors out
//error: Specified Channel Path is invalid
using (var elReader = new System.Diagnostics.Eventing.Reader.EventLogReader(elQuery))
{
List<EventRecord> eventList = new List<EventRecord>();
EventRecord eventInstance = elReader.ReadEvent();
try
{
while ((eventInstance = elReader.ReadEvent()) != null)
{
//Access event properties here:
string formatDescription = eventInstance.FormatDescription();
MessageBox.Show(formatDescription);
}
}
finally
{
if (eventInstance != null)
eventInstance.Dispose();
}
}
}
I have iterated
foreach (var tmp_variable in all_subdirectories)
{
MessageBox.Show(tmp_variable["Name"]);
}
I want to print the Name inside tmp_variable .
In the Autos tab (While Debugging the variable value), the tmp_variable has the following values:
tmp_variable { Path = "D:\abc\folder1", Name = "folder1" }
But unable to use any of such things.
I have tried writing
MessageBox.Show(tmp_variable[Name]);
and,
MessageBox.Show(tmp_variable.Name);
But nothing works. Everything shows error.
I hope this helps.
var all_subdirectories = System.IO.Directory.GetDirectories(folderPath);
foreach (var tmp_variables in all_subdirectories)
{
// Get the directory name only from filepath
MessageBox.Show(System.IO.Path.GetFileName(tmp_variables));
}
Solved - Accidentally wiped the actual file of data but the ide doesn't update that file unless you reopen it so I thought the data was still in there.
I'm working on a project in C# that reads in a fake inventory and then transactions to go with that inventory in another class. I know the code is quite messy at the moment, i'm just trying to figure out one thing specifically.
this code here will read in my file "Inventory.in", check if the file exists(which it does) and then start my streamreader and readline into a string.
private void btnFill_Click(object sender, EventArgs e)
{
string strInputLine;
string inFile = "Inventory.in";
StreamReader iSR;
InvRec currInvent;
if (File.Exists(inFile))
{
iSR = new StreamReader(inFile);
strInputLine = iSR.ReadLine();
while (strInputLine != null)
{
all of it isn't there but the point of emphasis is that the
"strInputLine = iSR.ReadLine();"
does indeed give me the correct value from that file.
now moving on to my question, the second block of code from another button is below:
private void btnProcess_Click(object sender, EventArgs e)
{
string strInputVal;
string inFileName = "Transactions.in";
TransRec currTrans;
StreamReader iSR2;
transListClass transactionList = new transListClass();
InvRec inventItem = inventoryList.Retrieve();
if (File.Exists(inFileName))
{
iSR2 = new StreamReader(inFileName);
strInputVal = iSR2.ReadLine();
while (strInputVal != null)
{
my problem lies when I try and do my ReadLine() into iSR2. it gives me null instead of the value from the file I'm supposed to get. Everything is the same otherwise, it just refuses to give me the correct value. I'm following the debugger in Visual Studio 2010, so I know the file is found and exists, I see it being opened, just a null value instead of my string I need.
Thank you to anybody in advance, I appreciate it.
-Anthony
edit:
the second block of code is supposed to read from "Transactions.in" instead of the first one that reads from "Inventory.in"
Important edit:
I have noticed when i changed "Transactions.in" to "Inventory.in" in the second block of code for the process button, it reads the values from Inventory.in and gives me a proper string unlike null from Transactions.in. The file is found and is just a text file named Transactions.in that was provided by my teacher, nobody else had a problem with it.
I've got a very strange issue while parsing an external XAML file. The pre-history is that I want to load an external XAML file with content to process. But I want to load as many different files as I want. That happens by unloading the old and loading the new one.
My issue is:
When I load a xaml the first time, everything is good, all as it should be.
But when I load the same xaml the second time, every entry of the object im Loading is there twice. If I run this again, every object is there three times and so on...
To debug the project yourself, download it here. The function starts at line 137 in the file "Control Panel.xaml.cs". I realy don't know what this is. Is it my fault or simply a bug? If yes, is there a workaround?
/// <summary>
/// Load a xaml file and parse it
/// </summary>
public void LoadPresentation()
{
this.Title = "Control Panel - " + System.IO.Path.GetFileName(global.file);
System.IO.FileStream XAML_file = new System.IO.FileStream(global.file, System.IO.FileMode.Open);
try
{
System.IO.StreamReader reader = new System.IO.StreamReader(XAML_file);
string dump = reader.ReadToEnd(); //This is only for debugging purposes because of the strange issue...
XAML_file.Seek(0, System.IO.SeekOrigin.Begin);
presentation = (ResourceDictionary)XamlReader.Load(XAML_file);
//Keys the resourceDictionary must have to be valid
if (presentation["INDEX"] == null || presentation["MAIN_GRID"] == null || presentation["CONTAINER"] == null || presentation["LAYOUTLIST"] == null)
{
throw new Exception();
}
//When this list is loaded, every item in it is there twice or three times or four... Why????
TopicList Index = null;
Index = (TopicList)presentation["INDEX"];
for (int i = 0; i < topics.Count; )
{
topics.RemoveAt(i);
}
foreach (TopicListItem item in Index.Topics)
{
topics.Insert(item.TopicIndex, (Topic)presentation[item.ResourceKey]);
}
lv_topics.SelectedIndex = 0;
selectedIndex = 0;
}
catch
{
System.Windows.Forms.MessageBox.Show("Failed to load XAML file \"" + global.file + "\"", "Parsing Error", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);
presentation = null;
}
finally
{
XAML_file.Close();
}
}
Edit:
I have tried to serialize the object that was read from the XamlReader and in the output was nowhere any childelement... But if I pull the object out of the dictionary, the children are all there (duplicated and triplicated, but there).
I have already tried to clear the list over
topics.Clear();
and
topics=new ObservableCollection<TopicListItem>();
lv_topics.ItemsSource=topics;
Try Index.Topics.Clear() after loading the Topics into your topics object. That appears to get rid of the duplication.
//When this list is loaded, every item in it is there twice or three times or four... Why????
TopicList Index = null;
Index = (TopicList)presentation["INDEX"];
topics.Clear();
foreach (TopicListItem item in Index.Topics)
{
topics.Insert(item.TopicIndex, (Topic)presentation[item.ResourceKey]);
}
Index.Topics.Clear(); //Adding this will prevent the duplication
lv_topics.SelectedIndex = 0;
selectedIndex = 0;
In the code post topics is not declared in LoadPresentation() so naturally it will have any prior values.
I know you said you tried topics=new ObservableCollection(); but please try again. And put that IN LoadPresentation()
public void LoadPresentation()
{
ObservableCollection<TopicListItem> topics = new ObservableCollection<TopicListItem>()
I would pass filename
public void LoadPresentation(string fileName)
I get you may need to use topics outside LoadPresentation but this is debugging. If you need topics outside the return it.
public ObservableCollection<TopicListItem> LoadPresentation(string fileName)
If that does not fix it I would put a try catch block on the XAML_file.Close(); to see if something weird is not going on.
I am a bit new at C# and I have run into a string concatenation issue. I am hoping someone might be able to give me a hint and help me resolve this. I have searched Google extensively and have spent more than a week on this so any help/advice would be greatly appreciated.
I have created a custom PathEditor for a string property. The property basically allows the user to key in a file to use in the app. If the file typed in is correct, it shows in the property cell as it should. What I am trying to do is output to the property cell an error message if the file typed in does not exist - I check this in my file validator. Here is the string literal issue.
If I use:
return inputFile+"Error_";
this works OK and I get the outpur file123.txtError_ in the property grid cell.
If I use:
return "Error_"+inputFile;
I get only the inputFile without the literal "Error_". Sot he property grid cell shows file123.txt in the property grid cell.
I have checked and inputFile is a string type. Any ideas as to why this is happening?
Also, is there any way to change to font, and/or, color of the message output? I tried to change the background of the property grid cell and I understand that this is not possible to do.
Thank you.
Z
More of the code:
[
Description("Enter or select the wave file. If no extension, or a non .wav extension, is specified, the default extension .wav will be added to the filename."),
GridCategory("Sound"),
Gui.Design.DisplayName ("Input Sound"),
PathEditor.OfdParamsAttribute("Wave files (*.wav)|*.wav", "Select Audio File"),
Editor(typeof(PathEditor), typeof(System.Drawing.Design.UITypeEditor))
]
public string InputWavefile
{
get { return System.IO.Path.GetFileName(inputtWavefile); }
set
{
if (value != inputWavefile) // inputWavefile has been changed
{
// validate the input stringg
_inputWavefile = FileValidation.ValidateFile(value);
// assign validated value
inputWavefile = _inputWavefile;
}
}
}
My guess is that you've got a funky character at the start of inputFile which is confusing things - try looking at it in the debugger using inputFile.ToCharArray() to get an array of characters.
The string concatenation itself should be fine - it's how the value is being interpreted which is the problem, I suspect...
I'm guessing your filename looks something like this, C:\Folder\FileName.txt when you start out.
In your FileValidation.ValidateFile() method you
return "Error_" + InputFileName;
it now looks like this: Error_C:\Folder\FileName.txt.
So, when you run the line below,
get { return System.IO.Path.GetFileName( _inputWavefile ); }
it strips off the path and returns the filename only, FileName.txt.
Even when the filename is not valid, you are still running System.IO.Path.GetFileName() on it.
Assuming this is a PropertyGrid in winforms app. Then it's neither a string concatenation issue, nor PropertyGrid issue, as could be proven by the following snippet. So you need to look elsewhere in your code:
public partial class Form1 : Form {
PropertyGrid pg;
public Form1() {
pg = new PropertyGrid();
pg.Dock = DockStyle.Fill;
this.Controls.Add(pg);
var inputFile = "some fileName.txt";
var obj = new Obj();
obj.One = "Error_" + inputFile;
obj.Two = inputFile + "Error_";
pg.SelectedObject = obj;
}
}
class Obj {
public string One { get; set; }
public string Two { get; set; }
}