When adding a Next and Previous navigation option to my Image viewer coded in C#, when I press Next about 20 or so times, Visual Studio tells me the process ran out of memory. It does this in any folder with many even if the image file sizes for them all are tiny
I get:
An unhandled exception of type 'System.OutOfMemoryException' occurred in System.Drawing.dll Additional information: Out of memory.
This is the code I am using
private void next_Click(object sender, EventArgs e)
{
string[] foldernm = Directory.GetFiles(Path.GetDirectoryName(lfoto_file.FileName));
_pictureIndex++;
if (_pictureIndex >= foldernm.Length)
{
_pictureIndex = 0;
}
ibread_img.Image.Dispose();
ibread_img.Image = Image.FromFile(foldernm[_pictureIndex]);
}
Now as you can see, I have ibread_img.Image.Dispose(); there because I have searched about this and other people said to use that, but it doesn't work and I still get the same problem, a break-point confirms the code is being ran so I am confused to why its still running out of memory. The images I am cycling through are not large. I have tried everything I could find including nulling the previously loaded image, manually calling the garbage collector and nothing seems to work. I am not the best at C# so there might be a horrible mistake or flaw in that code but I don't know, any ideas on how to fix this?
There are a couple of things you could do to improve your viewer. First, you are recreating the list of image files every time; you are loading all of them each time just to access the next one and you dont have to create an image in order to show it.
// class level vars
int picIndex = 0;
IEnumerable<string> files;
int filesCount;
string picPath;
static string[] imgExts = {".png", ".jpg",".gif"};
Since you mentioned a Next and Previous button, you must have almost the same code elsewhere. This will eliminate that duplication, Next:
ShowImage(picIndex);
picIndex+=1;
if (picIndex >= filesCount)
picIndex = 0;
Then a method to show the desired image:
private void ShowImage(int Index)
{
// create image list if needed (once)
if (files == null)
{
files = new DirectoryInfo(picPath).EnumerateFiles().
Where(q => imgExts.Contains(q.Extension.ToLowerInvariant())).
Select( z => z.FullName);
filesCount = files.Count();
}
string thisFile = files.ElementAt(Index);
// no need to dispose an image if you never create one
pb2.ImageLocation = thisFile;
lblImgName.Text = Path.GetFileName(thisFile);
}
Rather that create the list of files each time (in 2 places) this does it once ever, and instead of loading a List of all of them, this leaves it as IEnumerable to get them as needed. It also works off FileInfo, is case insensitive mainly to illustrate a different way which would allow you to sort them (OrderBy) by the created date, if you wanted.
Finally, given the full path and file name, you can use the .ImageLocation property and avoid creating and disposing of Images.
The main thing is to minimize the amount of repeated code so you Dont Repeat Yourself. The code for Next and Previous is going to be almost identical.
Thanks to LarsTech and Plutonix for pointing out my mistake. This new code works fine now:
private void next_Click(object sender, EventArgs e)
{
var filteredFiles = Directory.EnumerateFiles(Path.GetDirectoryName(lfoto_file.FileName))
.Where(file => file.ToLower().EndsWith("jpg") || file.ToLower().EndsWith("png") || file.ToLower().EndsWith("gif") || file.ToLower().EndsWith("bmp") || file.ToLower().EndsWith("tiff") || file.ToLower().EndsWith("ico"))
.ToList();
_pictureIndex++;
if (_pictureIndex >= filteredFiles.Count)
{
_pictureIndex = 0;
}
ibread_img.Image.Dispose();
ibread_img.Image = Image.FromFile(filteredFiles[_pictureIndex]);
init();
}
I just needed to filter out the correct formats.
Related
I keep getting a Null Object Refrence Error, but can't tell why.
I have a CSV file that contains 100 urls. The file is read into an array called "lines".
public partial class Form1 : System.Windows.Forms.Form
{
string[] lines;
public Form1() ...
private void ReadLinksIntoMemory()
{
//this reads the chosen csv file into our "lines" array
//and splits on comma's and new lines to create new objects within the array
using (StreamReader sr = new StreamReader(#"C:\temp.csv"))
{
//reads everything in our csv into 1 long line
string fileContents = sr.ReadToEnd();
//splits the 1 long line read in into multiple objects of the lines array
lines = fileContents.Split(new string[] { ",", Environment.NewLine },
StringSplitOptions.RemoveEmptyEntries);
sr.Dispose();
}
}
The next part is where I get the null object error. When I try to use WatIn to go to the first item in the lines array it says I'm referencing a null object.
private void GoToEditLinks()
{
for (int i = 0; i < lines.Length; i++)
{
//go to each link sequentially
myIE.GoTo(lines[i].ToString());
//sleep so we can make sure the page loads
System.Threading.Thread.Sleep(5000);
}
}
When I debug the code it says that the GoTo request calls lines which is null.
It seems like I need to declare the array, but don't I need to tell it an exact size to do that? Example:
lines = new string[10]
I thought I could use the lines.Length to tell it how big to make the array but that didn't work. What is weird to me is I can use the following code without problem:
//returns the accurate number of urls that were in the CSV we read in earlier
txtbx1.text = lines.Length;
//or
//this returns the last entry in the csv, as well as the last entry in the array
TextBox2.Text = lines[lines.Length - 1];
I am confused why the array clearly has items in it, they can be called to fill a text box, but when I try to call them in my for loop it says its a null reference?
UPDATE:
By placing my cursor on both calls to lines and pressing f12 I find they both go to the same instance. The thought next is that I am not calling ReadLinksIntoMemory in time, below is my code:
private void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
ReadLinksIntoMemory();
GoToEditLinks();
button1.Enabled = true;
}
Unless I'm mistaken the code says that the ReadLinksIntoMemory method must complete before GoToEditLinks can be called? If ReadLinksIntoMemory didn't finish in time I shouldn't be able to fill my text boxes with the lines array length and/or last entry.
UPDATE: Stepping into the method GoToEditLinks() I see that lines is null before it calls:
myIE.GoTo(lines[i]);
but when it hits the goto command the value changes from null to the url it is suppose to go to, but at that same time it gives me the null object error?
UPDATE:
I added a IsNullOrEmpty check method and lines array passes it without any issue. I'm beginning to think it is an issue with WatIn and the myIE.GoTo command.
I think this is the stack trace/call stack?
Program.exe!Program.Form1.GoToEditLinks() Line 284 C#
Program.exe!Program.Form1.button1_Click(object sender, System.EventArgs e) Line 191 + 0x8 bytes C#
[External Code]
Program.exe!Program.Program.Main() Line 18 + 0x1d bytes C#
[External Code]
SOLUTION:
It turns out the issue WAS WatIn. Under normal circumstances I have initialized the myIE object but in this instance I was doing a shorthand test on those two methods which meant that the myIE object had not yet been created! I ran the method to initialize the myIE object first and it worked. Thank you everyone for helping me work through this.
The code in the first 2 samples looks OK, provided ReadLinksIntoMemory() runs first. It creates the lines array.
Try this:
put your cursor on lines inside ReadLinksIntoMemory, pres F12. It should go to the declaration at the top of the class.
put your cursor on lines inside GoToEditLink. It should take you to the same declaration.
Either you'll find that there are 2 declaration for lines or that you don't call ReadLinksIntoMemory() on time.
You should not need lines = new string[10] .
Step 2: put breakpoints at the start of both ReadLinksIntoMemory and GoToEditLink. Make sure the first one breaks first.
Then inside GoToEditLink, carefully check lines, lines.Length and (some of) its contents.
This variation of String.Split() should not produce null entries but still:
for (int i = 0; i < lines.Length; i++)
{
//go to each link sequentially
string line = lines[i];
myIE.GoTo(line); // set a breakpoint here with the Condition `line == null`.
...
}
Note that there is no reason for .ToString() on an element from a string[]
Can't see from your code why lines or lines[i] would be null, but that's what it's saying.
Test both for null / IsNullOrEmpty, it's good practice anyway, add an else and throw say an ArgumentNullException, stick a debug on that and hit go. Things might become clearer.
All, I'm working on what I thought was a fairly simple app. I'm using multiple view controllers with a view - under which there are buttons and a single image view. the buttonpress event triggers the other viewcontroller's view to display. That works perfectly. However, I'm also wanting to animate the transition to simulate a page turn. I use the code below to do that. It works well, however, every time I use this method the memory used increases. The memory used appears to be disconnected from the actual size of the image array. Also, I changed from png to jpeg ( much smaller images ) and it doesn't make a bit of difference. I thought about using .mov but the load time is very noticeable.
Please help. I've tried a ton of different way to force garbage collection. I've dug through the limited texts, and searched this website to no avail.
Here's a sample of the code.
public partial class AppDelegate : UIApplicationDelegate
{
// This method is invoked when the application has loaded its UI and its ready to run
public override bool FinishedLaunching (UIApplication app, NSDictionary options)
{
UIApplication.SharedApplication.SetStatusBarHidden( true, true);
// If you have defined a view, add it here:
// window.AddSubview (navigationController.View);
//window.AddSubview(mainController.View);
window.MakeKeyAndVisible ();
coverOpenbtn.TouchUpInside += HandleCoverOpenbtnTouchUpInside;
backBtn1.TouchUpInside += HandleBackBtn1TouchUpInside;
return true;
}
void HandleBackBtn1TouchUpInside (object sender, EventArgs e)
{
this.navView.RemoveFromSuperview();
List<UIImage> myImages = new List<UIImage>();
myImages.Add(UIImage.FromFile("c_1_00011.jpg"));
myImages.Add(UIImage.FromFile("c_1_00010.jpg"));
myImages.Add(UIImage.FromFile("c_1_00009.jpg"));
myImages.Add(UIImage.FromFile("c_1_00008.jpg"));
myImages.Add(UIImage.FromFile("c_1_00007.jpg"));
myImages.Add(UIImage.FromFile("c_1_00006.jpg"));
myImages.Add(UIImage.FromFile("c_1_00005.jpg"));
myImages.Add(UIImage.FromFile("c_1_00004.jpg"));
myImages.Add(UIImage.FromFile("c_1_00003.jpg"));
myImages.Add(UIImage.FromFile("c_1_00002.jpg"));
myImages.Add(UIImage.FromFile("c_1_00001.jpg"));
myImages.Add(UIImage.FromFile("c_1_00000.jpg"));
//myImages.Add(UIImage.FromFile("c_1_00012.jpg"));
var myAnimatedView = new UIImageView(window.Bounds);
myAnimatedView.AnimationImages = myImages.ToArray();
myAnimatedView.AnimationDuration = 1; // Seconds
myAnimatedView.AnimationRepeatCount = 1;
myAnimatedView.StartAnimating();
window.AddSubview(myAnimatedView);
}
void HandleCoverOpenbtnTouchUpInside (object sender, EventArgs e)
{
this.coverView.AddSubview(navView);
List<UIImage> myImages = new List<UIImage>();
myImages.Add(UIImage.FromFile("c_1_00000.jpg"));
myImages.Add(UIImage.FromFile("c_1_00001.jpg"));
myImages.Add(UIImage.FromFile("c_1_00002.jpg"));
myImages.Add(UIImage.FromFile("c_1_00003.jpg"));
myImages.Add(UIImage.FromFile("c_1_00004.jpg"));
myImages.Add(UIImage.FromFile("c_1_00005.jpg"));
myImages.Add(UIImage.FromFile("c_1_00006.jpg"));
myImages.Add(UIImage.FromFile("c_1_00007.jpg"));
myImages.Add(UIImage.FromFile("c_1_00008.jpg"));
myImages.Add(UIImage.FromFile("c_1_00009.jpg"));
myImages.Add(UIImage.FromFile("c_1_00010.jpg"));
myImages.Add(UIImage.FromFile("c_1_00011.jpg"));
//myImages.Add(UIImage.FromFile("c_1_00012.jpg"));
var myAnimatedView = new UIImageView(window.Bounds);
myAnimatedView.AnimationImages = myImages.ToArray();
myAnimatedView.AnimationDuration = 1; // Seconds
myAnimatedView.AnimationRepeatCount = 1;
opened++;
}
myAnimatedView.StartAnimating();
window.AddSubview(myAnimatedView);
}
Here's a few hints (just by reading the code):
There no difference between JPEG and PNG once the images are loaded in memory. The format only matters when the image is stored, not displayed. Once loaded (and decompressed) they will take a bit over (Width * Height * BitCount) of memory.
Consider caching your images and load them only they are not available. The GC will decide when to collect them (so many copies could exists at the same time). Right now you're loading each image twice when you could do it once (and use separate array for ordering them).
Even if you cache them also be ready to clear them on demand, e.g. if iOS warns you memory is low. Override ReceiveMemoryWarning to clear your list (or better arrays).
Don't call ToArray if you can avoid it (like your sample code). If you know how many images you have them simply create the array with the right size (and cache both array too ;-). It will cut down (a bit) the allocations;
Even consider caching the 'myAnimatedView' UIImageView (if the above did not help enough)
Be helpful to others, try them one-by-one and tell us what help you the most :-)
The images are to "animate" a page turn...is this to navigate through the app?
E.g. you start at the "home" page, press a button then it animates a page turn to the next screen in your app?
I think you would be better off looking at using CoreGraphics to try and achieve this effect, it'll both be a lot more efficient memory wise, and it will probably look a lot better as well. There are a few projects in Objective-C to get you started, such as Tom Brow's excellent Leaves project.
Okay, here is the best solution I found, doesn't crash the hardware, and is generally useful for other tasks.
This is the code that goes in the handler for the button press, each NavImage is a UIImage I built under the same view in interface builder. I just turned the alpha to 0 initially, and light them up one by one...
NSTimer.CreateScheduledTimer(.1,delegate { navImage1.Alpha = 1; NSTimer.CreateScheduledTimer(.1,delegate { navImage2.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage3.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage4.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage5.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage6.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage7.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage8.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage9.Alpha = 1;
NSTimer.CreateScheduledTimer(.05,delegate { navImage.Alpha = 1; });});});});});});});});});});
public static class clsCounter
{
static int count;
public static int Counter
{
get { return count; }
set { count = value; }
}
}
The above is the static class that is used to record a number.
Also, I have two projects within a VS2010 solution, one of which is a class library. In one of these classes, I have got the following code which uses clsCounter.
if (clsCounter.Counter == 0)
countIES++;
else
countIES = 0;
Now, in the other project, I set some new values to clsCounter
clsCounter.Counter = 50;
However, for some reason, I am not able to set clsCounter.Counter to 50, thus I always get countIES++. The code looks okay to me, and I have no idea what's wrong with it? Can anyone help?
Thanks.
EDIT:
I wonder if it has something to do with the scope of projects within vs solution?
Solution Structure
Solution
ExcelAddIn
Form1.cs => (clsCounter.Counter = 50)
...
ClassLibrary
clsCounter => (static class)
...
EDIT 2:
clsCounter.Counter = 50; is actually running in backgroundworker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) event. Could this be a possible issue?
EDIT 3:
I have uploaded a sample project that seems to be able to reproduce the same problem. Here's the shared link: => http://www.4shared.com/folder/sInyNWyi/_online.html
What I would like to do here is to populate a cell with value, Other case after the button 'set value' is pressed. The static class and UDF can be found in the class library.
Note that, to be able to use =testFunc() within excel addin, need to find it in automation server list and enable it. So just go File->Option->Addin->Under Manage Add-in->Click GO->Automation->Ebale ClassLibrary1.UDF
Please also check if the option "Register for COM interop" has been enabled or not before launching the debugger. To find it, go ClassLibrary1 Property -> Build -> Under Output, check Register for COM interop.
Add the following line to your static property:
public static class clsCounter
{
private static int count;
public static int Counter
{
get {
Debug.WriteLine("Counter viewed");
return count;
}
set {
Debug.WriteLine("Counter Changed from {0} to {1}", count, value);
count = value;
}
}
}
Then you can watch your debugger and set breakpoints on the counter which will allow you to find out which part of the code is modifying your counter inappropriately. A static counter will be initialised "at some time" before it is accessed. I would say you are setting the counter and something somewhere is immediately incrementing it before you read it.
Finally, I think I found a workaround although it had nothing to do with the static. I was kinda inspired by the idea of using cookies in the web apps.
Similarly, all I need to do here is:
store a value in a temporary text file, by doing
System.IO.File.WriteAllText(#"C:\countIESValue.txt", value);
in the "set value" button click event handler.
And read the stored value whenever I need it from the above text file and assign it to a local variable.
if(System.IO.File.Exists(#"C:\countIESValue.txt"))
{
string val = System.IO.File.ReadAllText(#"C:\countIESValue.txt");
}
The text file can also be deleted after done processing. In this way, I don't have to worry about any scope or application domain issues, although the permission of writing files is required. I am glad it worked pretty all right for me.
I'm trying to find a way for my program to know when a WebBrowser is navigating and when is not. This is because the program will interact with the loaded document via JavaScript that will be injected in the document. I don't have any other way to know when it starts navigating than handling the Navigating event since is not my program but the user who will navigate by interacting with the document. But then, when DocumentCompleted occurs doesn't necessarily mean that it have finished navigating. I've been googling a lot and found two pseudo-solutions:
Check for WebBrowser's ReadyState property in the DocumentCompleted event. The problem with this is that if not the document but a frame in the document loads, the ReadyState will be Completed even if the main document is not completed.
To prevent this, they advise to see if the Url parameter passed to DocumentCompleted matches the Url of the WebBrowser. This way I would know that DocumentCompleted is not being invoked by some other frame in the document.
The problem with 2 is that, as I said, the only way I have to know when a page is navigating is by handling the Navigating (or Navigated) event. So if, for instance, I'm in Google Maps and click Search, Navigating will be called, but just a frame is navigating; not the whole page (on the specific Google case, I could use the TargetFrameName property of WebBrowserNavigatingEventArgs to check if it's a frame the one that is navigating, but frames doesn't always have names). So after that, DocumentCompleted will be called, but not with the same Url as my WebBrowsers Url property because it was just a frame the one that navigated, so my program would thing that it's still navigating, forever.
Adding up calls to Navigating and subtracting calls to DocumentCompleted wont work either. They are not always the same. I haven't find a solution to this problem for months already; I've been using solutions 1 and 2 and hoping they will work for most cases. My plan was to use a timer in case some web page has errors or something but I don't think Google Maps has any errors. I could still use it but the only uglier solution would be to burn up my PC.
Edit: So far, this is the closest I've got to a solution:
partial class SafeWebBrowser
{
private class SafeNavigationManager : INotifyPropertyChanged
{
private SafeWebBrowser Parent;
private bool _IsSafeNavigating = false;
private int AccumulatedNavigations = 0;
private bool NavigatingCalled = false;
public event PropertyChangedEventHandler PropertyChanged;
public bool IsSafeNavigating
{
get { return _IsSafeNavigating; }
private set { SetIsSafeNavigating(value); }
}
public SafeNavigationManager(SafeWebBrowser parent)
{
Parent = parent;
}
private void SetIsSafeNavigating(bool value)
{
if (_IsSafeNavigating != value)
{
_IsSafeNavigating = value;
OnPropertyChanged(new PropertyChangedEventArgs("IsSafeNavigating"));
}
}
private void UpdateIsSafeNavigating()
{
IsSafeNavigating = (AccumulatedNavigations != 0) || (NavigatingCalled == true);
}
private bool IsMainFrameCompleted(WebBrowserDocumentCompletedEventArgs e)
{
return Parent.ReadyState == WebBrowserReadyState.Complete && e.Url == Parent.Url;
}
protected void OnPropertyChanged(PropertyChangedEventArgs e)
{
if (PropertyChanged != null) PropertyChanged(this, e);
}
public void OnNavigating(WebBrowserNavigatingEventArgs e)
{
if (!e.Cancel) NavigatingCalled = true;
UpdateIsSafeNavigating();
}
public void OnNavigated(WebBrowserNavigatedEventArgs e)
{
NavigatingCalled = false;
AccumulatedNavigations++;
UpdateIsSafeNavigating();
}
public void OnDocumentCompleted(WebBrowserDocumentCompletedEventArgs e)
{
NavigatingCalled = false;
AccumulatedNavigations--;
if (AccumulatedNavigations < 0) AccumulatedNavigations = 0;
if (IsMainFrameCompleted(e)) AccumulatedNavigations = 0;
UpdateIsSafeNavigating();
}
}
}
SafeWebBrowser inherits WebBrowser. The methods OnNavigating, OnNavigated and OnDocumentCompleted are called on the corresponding WebBrowser overridden methods. The property IsSafeNavigating is the one that would let me know if it's navigating or not.
Waiting till the document has loaded is a difficult problem, but you want to continually check for .ReadyState and .Busy (dont forget that). I will give you some general information you will need, then I will answer your specific question at the end.
BTW, NC = NavigateComplete and DC = DocumentComplete.
Also, if the page you are waiting for has frames, you need to get a ref to them and check their .busy and .readystate as well, and if the frames are nested, the nested frames .readystate and .busy as well, so you need to write a function that recursively retreives those references.
Now, regardless of how many frames it has, first fired NC event is always the top document, and last fired DC event is always that of the top (parent) document as well.
So you should check to see if its the first call and the pDisp Is WebBrowser1.object (literally thats what you type in your if statement) then you know its the NC for top level document, then you wait for this same object to appear in a DC event, so save the pDisp to a global variable, and wait until a DC is run and that DC's pDisp is equal to the Global pDisp you've saved during the first NC event (as in, the pDisp that you saved globally in the first NC event that fired). So once you know that pDisp was returned in a DC, you know the entire document is finished loading.
This will improve your currect method, however, to make it more fool proof, you need to do the frames checking as well, since even if you did all of the above, it's over 90% good but not 100% fool proof, need to do more for this.
In order to do successful NC/DC counting in a meaningful way (it is possible, trust me) you need to save the pDisp of each NC in an array or a collection, if and only if it doesn't already exist in that array/collection. The key to making this work is checking for the duplicate NC pDisp, and not adding it if it exists. Because what happens is, NC fires with a particular URL, then a server-side redirect or URL change occurs and when this happens, the NC is fired again, BUT it happens with the same pDisp object that was used for the old URL. So the same pDisp object is sent to the second NC event now occuring for the second time with a new URL but still all being done with the exact same pDisp object.
Now, because you have a count of all unique NC pDisp objects, you can (one by one) remove them as each DC event occurs, by doing the typical If pDisp Is pDispArray(i) Then (this is in VB) comparison wrapped in a For Loop, and for each one taken off, your array count will get closer to 0. This is the accurate way to do it, however, this alone is not enough, as another NC/DC pair can occur after your count reaches 0. Also, you got to remember to do the exact same For Loop pDisp checking in the NavigateError event as you do in the DC event, because when a navigation error occurs, a NavigateError event is fired INSTEAD of the DC event.
I know this was a lot to take, but it took me years of having to deal with this dreaded control to figure these things out, I've got other code & methods if you need, but some of the stuff I mentioned here in relation to WB Navigation being truely ready, haven't been published online before, so I really hope you find them useful and let me know how you go. Also, if you want/need clarification on some of this let me know, unfortunately, the above isn't everything if you want to be 100% sure that the webpage is done loading, cheers.
PS: Also, forgot to mention, relying on URL's to do any sort of counting is inaccurate and a very bad idea because several frames can have the same URL - as an example, the www.microsoft.com website does this, there are like 3 frames or so calling MS's main site that you see in the address bar. Don't use URL's for any counting method.
First I've converted the document to XML and then used my magic method:
nodeXML = HtmlToXml.ConvertToXmlDocument((IHTMLDocument2)htmlDoc.DomDocument);
if (ExitWait(false))
return false;
conversion:
public static XmlNode ConvertToXmlDocument(IHTMLDocument2 doc2)
{
XmlDocument xmlDoc = new XmlDocument();
IHTMLDOMNode htmlNodeHTML = null;
XmlNode xmlNodeHTML = null;
try
{
htmlNodeHTML = (IHTMLDOMNode)((IHTMLDocument3)doc2).documentElement;
xmlDoc.AppendChild(xmlDoc.CreateXmlDeclaration("1.0", ""/*((IHTMLDocument2)htmlDoc.DomDocument).charset*/, ""));
xmlNodeHTML = xmlDoc.CreateElement("html"); // create root node
xmlDoc.AppendChild(xmlNodeHTML);
CopyNodes(xmlDoc, xmlNodeHTML, htmlNodeHTML);
}
catch (Exception err)
{
Utils.WriteLog(err, "Html2Xml.ConvertToXmlDocument");
}
magic method:
private bool ExitWait(bool bDelay)
{
if (m_bStopped)
return true;
if (bDelay)
{
DateTime now = DateTime.Now;
DateTime later = DateTime.Now;
TimeSpan difT = (later - now);
while (difT.TotalMilliseconds < MainDef.IE_PARSER_DELAY)
{
Application.DoEvents();
System.Threading.Thread.Sleep(10);
later = DateTime.Now;
difT = later - now;
if (m_bStopped)
return true;
}
}
return m_bStopped;
}
where m_bStopped is false by default, IE_PARSER_DELAY is a timeout value.
I hope this helps.
Below is a method that I want to ship off into a background worker but I am struggling how to do it based on how created my method. As you can it doesn't return anything which is ok but it expects a directoryInfo object everytime it is recalled.
private void getSizeForTargetDirectory(DirectoryInfo dtar)
{
// generate a collection of objects. files comes first and then directories.
foreach (Object item in collection )
{
if (item == file)
{
track the size of the files as you encounter.
}
else if (item == directory)
{
// found a new directory, recall the method. !!!
}
}
}
This is my first time using a background worker so I'm a little stuck, I tried implementing something thanks to the help found here but got stuck when I realised my method was recursive.
How do I display progress during a busy loop?
I implemented a doWork event handler method but noticed that i needed to somehow recall the method if I had more files and folders to process on lower sub levels.
I have a simple button click event handler that calls my 'getSizeForTargetDirectory()' method when the current selected node is a directory.
private void retrieveInfoButton_Click(object sender, EventArgs e)
{
// check to see if the path is valid
// reset the labels and textfields.
string fullPath = treeDrives.SelectedNode.FullPath;
string sNodesName = treeDrives.SelectedNode.Text;
if (directory) // Enter here if its a directory.
{
string parentPath = treeDrives.SelectedNode.Parent.FullPath;
DirectoryInfo[] dirArray = populateFoldersArray(parentPath);
for (int i = 0; i < dirArray.Length; i++)
{
if (dirArray[i].Name == sNodesName)
{
getSizeForTargetDirectory(dirArray[i]);
// do work !
Hopefully that explains what I am trying to do and how I am doing it. Question is how can i use the report progress feature of the background worker class when the bulk of the work I am trying to ship is coming from a recursive method.
Through early testing I noticed that my getSize method was incredibly efficient after a few tweaks and reported size information for the current supplied folder very quickley but then again I use quite a powerful dev machine so this may not be true for all users.
Thanks For Reading, Hope someone can help !!!
I think it is much simpler to use the built-in methods on either Directory or DirectoryInfo to obtain all directories, or files, using the recursive search option:
public partial class Form1 : Form
{
private Action<float> updateProgMethod;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
updateProgMethod = UpdateProgress;
}
private void GetDirectorySizeAsync(string path)
{
backgroundWorker.RunWorkerAsync(path);
}
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
DirectoryInfo di = new DirectoryInfo((string)e.Argument);
di.GetTotalSize(ProgressCallback);
}
// Takes callbacks from the GetTotalSize() method
private void ProgressCallback(float p)
{
// Invokes update progress bar on GUI thread:
this.BeginInvoke(updateProgMethod, new object[] { p });
}
// Actually updates the progress bar:
private void UpdateProgress(float p)
{
progressBar.Value = (int)(p * (progressBar.Maximum - progressBar.Minimum)) + progressBar.Minimum;
}
}
public static class IOExtensions
{
public static long GetTotalSize(this DirectoryInfo directory, Action<float> progressCallback)
{
FileInfo[] files = directory.GetFiles("*.*", SearchOption.AllDirectories);
long sum = 0;
int countDown = 0;
for (int i = 0; i < files.Length; i++)
{
sum += files[i].Length;
countDown--;
if (progressCallback != null && countDown <= 0)
{
countDown = 100;
progressCallback((float)i / files.Length);
}
}
return sum;
}
}
It's hard to guess progress without knowing the number of files or folders first!
EDIT: I've improved the code a little.
If, when you call a method, you don't know how long the method is going to take or how many discrete steps are going to be involved, then there is no way to display a progress bar while the method is executing.
In my opinion, the purpose of a progress bar is not to give reliable information about when a task is going to be completed. Rather, the purpose is to keep the user from freaking out and cancelling the whole operation because they think your program has locked up and isn't doing anything at all.
Since you're iterating through directories and sub-directories, a simpler approach here might be to just display the current directory in a Label. This would give the user a relaxing sense that things are happening, and if the directories are all ordered alphabetically, they can even gauge for themselves the overall progress of the operation.
I would report how far you have gotten since you don't know the goal until you get there. I would do it once per invocation. Perhaps # of files and # of directories seen so far.