I'm getting several file links from a file into a loop statement and for each link , I have to download the file , when the download was completed I have to do something with each file.
Here is my code,
foreach(//condition ) {
Descarcare = new WebClient();
Descarcare.DownloadProgressChanged += Descarcare_DownloadProgressChanged;
Descarcare.DownloadFileAsync(new Uri(nod.SelectSingleNode("DownloadLink").InnerText), Directory.GetCurrentDirectory()+);
Descarcare.DownloadFileCompleted +=Descarcare_DownloadFileCompleted;
}
void Descarcare_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
{
//extract the file
}
But somehow , the webclient downloads the files but the DownloadFileCompleted event fires only for the last downloaded file instead of doing it for each file.
What can cause this?
You are creating a new WebClient in every iteration of your foreach-loop. The best approach is to create a Queue with all files and start a new download in each DownloadFileCompleted until you got all the files you want.
var _downloadQueue = new Queue<Uri>();
var _webClient = new WebClient();
//in your constructor:
_webClient.DownloadProgressChanged += Descarcare_DownloadProgressChanged;
_webClient.DownloadFileCompleted += Descarcare_DownloadFileCompleted;
private void Foo()
{
//...
foreach(/* condition */)
{
_downloadQueue.Enqueue(
new Uri(nod.SelectSingleNode("DownloadLink").InnerText)
);
}
DownloadNext();
}
private void DownloadNext()
{
if(_downloadQeue.Count> 0)
{
_webClient.DownloadFileAsync(
_downloadQueue.Dequeue(), Directory.GetCurrentDirectory()
);
}
}
void Descarcare_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
{
DownloadNext();
//extract the file
//...
}
Related
I'm monitoring a Folder for File creation(Copied) event using FileSystem Watcher. I only want the program to process image Files.
FileSystemWatcher watcher = new FileSystemWatcher();
watcher.Filter = "*.*";
watcher.Created += new FileSystemEventHandler(watcher_FileCreated);
watcher.Path = path;
So I try to create a Bitmap and avoid the file if an exception is thrown
private static void watcher_FileCreated(object sender, FileSystemEventArgs e)
{
try
{
using (Bitmap test = new Bitmap(Bitmap.FromFile(e.FullPath)))
{
mytoprocesslist.add(e.FullPath);
}
//do my processing with image
Console.WriteLine(e.FullPath);
}
catch (Exception error)
{
Console.WriteLine("File Error");
}
}
This throws Out of Memory exception even when a valid image file is copied, which I think happens because the event was raised before the file was copied completely. How can I get over this? I only want to add the valid image files to a to do list and I will process these images one by one later.
A bit cleaner solution than a Try-Catch might be this one.
Im using this code without any exceptions raised.
private static bool IsImage(string path) {
try {
var result = false;
using (var stream = new FileStream(path, FileMode.Open)) {
stream.Seek(0, SeekOrigin.Begin);
var jpg = new List<string> { "FF", "D8" };
var bmp = new List<string> { "42", "4D" };
var gif = new List<string> { "47", "49", "46" };
var png = new List<string> { "89", "50", "4E", "47", "0D", "0A", "1A", "0A" };
var imgTypes = new List<List<string>> { jpg, bmp, gif, png };
var bytesIterated = new List<string>();
for (var i = 0; i < 8; i++) {
var bit = stream.ReadByte().ToString("X2");
bytesIterated.Add(bit);
var isImage = imgTypes.Any(img => !img.Except(bytesIterated).Any());
if (isImage) {
result = true;
break;
}
}
}
return result;
} catch (UnauthorizedAccessException) {
return false;
}
}
Usage of code
foreach (var file in Directory.EnumerateFiles(#"pathToFlowersFolder"))
{
Console.WriteLine($"File: {file} Result:{IsImage(file)}");
}
Edit
After playing around i got an IO-Exception (File already in use)
After reading this i'd offer you the following solution:
private void button1_Click(object sender, EventArgs e)
{
var watcher = new FileSystemWatcher();
watcher.Created += new FileSystemEventHandler(fileSystemWatcher1_Changed);
watcher.Path = #"c:\temp";
watcher.NotifyFilter = NotifyFilters.FileName | NotifyFilters.Size;
watcher.EnableRaisingEvents = true;
}
private void fileSystemWatcher1_Changed(object sender, System.IO.FileSystemEventArgs e)
{
Thread.Sleep(100); // <- give the Creator some time. Increase value for greate pause
if (IsImage(e.FullPath))
{
Console.WriteLine("success----------->" + e.FullPath);
}
}
Note
This piece of code properly works on my machine. My HDD is an SSD, so you might need to increase the thread-sleeping time. It properly works for all images (jpg, bmp, gif, png) up to a size of 7 Mb (im quite sure and greater).
If this code doesnt works for you, please post the exception rather than uploading your code.
For the first requirement: "I only want the program to process image files"
private static void fileSystemWatcher1_Changed(object sender, FileSystemEventArgs e)
{
string strFileExt = getFileExt(e.FullPath);
// filter file types
if (Regex.IsMatch(strFileExt, #"\.png|\.jpg", RegexOptions.IgnoreCase))
{
//here Process the image file
}
}
For the second requirement: "Out of Memory Exception"
Here what happens is, when the file is created (only file name and some attributes) the system is calling the created event. Then the file changed event is also called
So you have to do the processing in the changed event. Also to prevent duplicate calling you have to add a filter to your watcher.
The following is the complete code.
private void fileSystemWatcher1_Changed(object sender, System.IO.FileSystemEventArgs e)
{
FileInfo fileInfo = new FileInfo(e.FullPath);
string strFileExt = fileInfo.Extension;
// filter file types
if (Regex.IsMatch(strFileExt, #"\.png|\.jpg", RegexOptions.IgnoreCase))
{
//here Process the image file
try
{
using (Bitmap test = new Bitmap(Bitmap.FromFile(e.FullPath)))
{
//Do your code here.
}
}
catch (Exception error)
{
Console.WriteLine("File Error");
}
}
}
private void Form1_Load(object sender, EventArgs e)
{
fileSystemWatcher1.Path = #"C:\Users\Christlin\Desktop\res";
//To Prevent duplicated calling of changed event
fileSystemWatcher1.NotifyFilter = NotifyFilters.FileName | NotifyFilters.Size;
}
My task is to delete file once the processing is completed . I am using FileWatcher to complete this task. It is watching specific folder . Suppose If i copy one file and put that in filewatcher folder it is deleting. Second time when i copy the same file and paste that in the same watching folder. This time it says that Another process is using that file . and exception is throwing . I think i am missing something. Here is my code
private static void Main(string[] args)
{
var fw = new FileSystemWatcher(EmailSetting.DataFolder)
{
IncludeSubdirectories = false
,
EnableRaisingEvents = true
};
fw.Created += (sender, e) =>
{
File.Delete(e.FullPath);
};
Console.ReadLine();
}
You receive the Created event when the file was created (hence the name). But at this point in time the other process that is actually creating it, didn't finish writing content into that file. So the file might be already there, but the other is still working on it (imagine you would copy a 8 GB file).
It would be wiser to simply write the path of the file into a list within the event and let another thread regularly check this concurrent bag (e.g. once a second). First it checks if the file exists and if yes, try to delete it. If succeeded, remove it from the bag, otherwise try again next time.
Code example
private static readonly ConcurrentQueue<FileInfo> _FileCandidates = new ConcurrentQueue<FileInfo>();
private static void Main(string[] args)
{
var watcher = new FileSystemWatcher
{
Path = #"R:\TestFolder",
IncludeSubdirectories = false,
Filter = "*.*",
};
Console.WriteLine("Start watching folder... " + watcher.Path);
watcher.Created += OnFileCreated;
watcher.EnableRaisingEvents = true;
var timer = new Timer
{
AutoReset = true,
Interval = 1000,
};
timer.Elapsed += OnTimerElapsed;
timer.Enabled = true;
Console.ReadKey();
}
static void OnTimerElapsed(object sender, ElapsedEventArgs e)
{
FileInfo file;
var stillInUseFiles = new List<FileInfo>();
Console.WriteLine("Check for file candidates...");
while (_FileCandidates.TryDequeue(out file))
{
try
{
Console.WriteLine("Delete " + file.FullName);
if (file.Exists)
file.Delete();
}
catch (IOException)
{
Console.WriteLine("Could not delete file, try again next time.");
stillInUseFiles.Add(file);
}
}
foreach (var unhappyFile in stillInUseFiles)
{
_FileCandidates.Enqueue(unhappyFile);
}
}
static void OnFileCreated(object sender, FileSystemEventArgs e)
{
Console.WriteLine("Found new file candidate " + e.FullPath);
_FileCandidates.Enqueue(new FileInfo(e.FullPath));
}
I'm making a WPF application where I use WebClient to download files form a webserver. I have a list of URL's with all the files i have to download. I use a foreach to loop through every URL and download each one at the time. The first URL much be completed before moving to the next one. I know the size of each file. Is there a way where I can set my e.ProgressPercentage to know the size of all files instead of loading from 0 to 100% for each file. I know that I'm calling DownloadProtocol for each URL right now, which makes a new instance of WebClient, but it is the only way I can think of to fulfill my solution, which is to download one file at a time.
public DownloadStart()
{
foreach(var url in ListOfDownloadURL)
{
DownloadGameFile dlg = new DownloadGameFile();
await dlg.DownloadProtocol(url, myLocation);
}
}
Download function in DownloadGameFile class:
public async Task DownloadProtocol(string address, string location)
{
Uri Uri = new Uri(address);
using (WebClient client = new WebClient())
{
//client.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
//client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgress);
client.DownloadProgressChanged += (o, e) =>
{
Console.WriteLine(e.BytesReceived + " " + e.ProgressPercentage);
//ProgressBar = e.ProgressPercentage (total)
};
client.DownloadFileCompleted += (o, e) =>
{
if (e.Cancelled == true)
{
Console.WriteLine("Download has been canceled.");
}
else
{
Console.WriteLine("Download completed!");
}
};
await client.DownloadFileTaskAsync(Uri, location);
}
}
Why not take the easy way out and just update the progress when file is completed? Something like...
ProgressBar p = new ProgressBar();
p.Maximum = ListOfDownloadURL.Count();
foreach(var url in ListOfDownloadURL)
{
DownloadGameFile dlg = new DownloadGameFile();
await dlg.DownloadProtocol(url, myLocation);
p.Value += 1;
}
Or if you insist, you could query file sizes before you begin downloading, sum total bytes of all the files and then calculate the percentage when ever DownloadProgressChanged is fired.
var bytes = Convert.ToInt64(client.ResponseHeaders["Content-Length"]);
How can I pause the loop in someRandomMethod() until the code in DownloadCompleted() have been executed? This code below only unpacks the latest version in the versions array. It's like the loop is faster than the first download and m_CurrentlyDownloading have the latest value the first time DownloadCompleted() is beeing executed.
private void someRandomMethod() {
for (int i = 0; i < versions.Count; i++)
{
//ClearInstallFolder();
m_CurrentlyDownloading = versions.ElementAt(i);
Download(versions.ElementAt(i));
LocalUpdate(versions.ElementAt(i));
System.Threading.Thread.Sleep(500);
}
}
private void Download(string p_Version)
{
string file = p_Version + ".zip";
string url = #"http://192.168.56.5/" + file;
//client is global in the class
client = new WebClient();
client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadCompleted);
client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressChanged);
client.DownloadFileAsync(new Uri(url), #"C:\tmp\" + file);
}
private void DownloadCompleted(object sender, AsyncCompletedEventArgs e)
{
if (e.Error == null)
{
Unpack(m_CurrentlyDownloading);
if (GetInstalledVersion() == GetLatestVersion())
ClearZipFiles();
}
else
MessageBox.Show(e.Error.ToString());
}
The easiest way would be to not use the *async methods. The normal DownloadFile will pause execution until it completes.
But if you've got access to the Await keyword, try this.
private async Task Download(string p_Version)
{
string file = p_Version + ".zip";
string url = #"http://192.168.56.5/" + file;
//client is global in the class
client = new WebClient();
client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadCompleted);
client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressChanged);
await client.DownloadFileAsync(new Uri(url), #"C:\tmp\" + file);
}
something like this can be used to wait
make it class property
bool IsDownloadCompleted=false;
Add this in DownloadCompletedEvent
IsDownloadCompleted=true;
and this where you want to stop loop
while(DownloadCompleted!=true)
{
Application.DoEvents();
}
Create some boolean variable, create a delegate and get\set methods for this variable.
Then just in loop made smth like :
while(!isDownLoadCompleted)Thread.Sleep(1024);
You Can use Paralel.ForEach. this loop will wait until all threads done.
check Here for how to use :
http://msdn.microsoft.com/tr-tr/library/dd460720(v=vs.110).aspx
or
http://blogs.msdn.com/b/pfxteam/archive/2012/03/05/10278165.aspx
I try to create a web browser. Currently I try to realize a function that if the user wants to download some file an additional window is shown with a list of already downloaded files. If the file has already been loaded, a message is shown (just an idea).
So far, I get a link to the file location in the main form and send it to the other form:
DownLoadFile dlf = new DownLoadFile();
...
WebBrowser wb = new WebBrowser();
wb.Navigating += new WebBrowserNavigatingEventHandler(wb_Navigating);
...
private void wb_Navigating(object sender, WebBrowserNavigatingEventArgs e)
{
...
if (e.Url.ToString().EndsWith(".mp3"))
{
dlf.DownloadPath = e.Url;
dlf.Show();
}
}
In the new form I try to use this link for file downloading:
public Uri DownloadPath { get; set; }
...
private void DownLoadFile_Load(object sender, EventArgs e)
{
string filePath = null;
//get FileName from URL
string[] ArrayForName;
ArrayForName = DownloadPath.ToString().Split('/');
saveFileDialogFile.FileName =
ArrayForName[ArrayForName.Length-1].Replace("%"," ").Trim();
if (saveFileDialogFile.ShowDialog() == DialogResult.OK)
{
WebClient client = new WebClient();
//get Url
Uri url = new Uri(DownloadPath.ToString());
//get place where want to save with default name
filePath = saveFileDialogFile.FileName;
//event for result
client.DownloadFileCompleted +=
new System.ComponentModel.AsyncCompletedEventHandler (client_DownloadFileCompleted);
//download
client.DownloadFileAsync(url, filePath);
}
}
void client_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
{
MessageBox.Show("Compleated");
}
My questions are:
Regarding if (e.Url.ToString().EndsWith(".mp3")) - How can i
change this for knowing not only when the user tries to download mp3 file,
but all types of files - maybe there is a better way
If i want to download a file using some link directly, I get the message "Currently you have not required permission for that" - How can I
change permission level for my web browser
If i finally get a link to the file and start to download it, as result just name of file (size of file 0 kb) - where i'm wrong.
my solution (maybe not the best one)
create event for webBrowser
wb.Navigating += new WebBrowserNavigatingEventHandler(wb_Navigating);
and in this event use next
if (GetWorkingWebBrowser().StatusText != null)
{
try
{
WebRequest request = WebRequest.Create(GetWorkingWebBrowser().StatusText);
request.Method = "HEAD";
using (WebResponse response = request.GetResponse())
{
if (response.ContentLength > 0 &&
!response.ContentType.ToString().ToLower().Contains("text/html"))
{
dlf.DownloadPath = e.Url; //move url to my form for dwnload
dlf.Show(); //show form
}
}
}
catch (UriFormatException)
{
}
catch (WebException)
{
}
}
GetWorkingWebBrowser() - method that return current active webBrowser on tab, meas webBrowser