C# webclient foreach download multiple file

It then uses an inside method to loop each link to attempt to download it and return them in a bitmap list. Finally the file system method can be used by passing the folder directory you wish it to search, then the image extension type.

As explained above, each bitmap is looped through to merge the images to the top left of the result Bitmap to create the final image. Like Liked by 1 person. It does not work for me. I have multiple images which needs to be merged one by one vertically, and also it should be resize as per the larger height and width of one of the images. Please help. Like Like. You are commenting using your WordPress. You are commenting using your Google account.

If I understand you correctly, this should do the trick. You'll need add using System. IO at the top of your file if you don't already have it. The simplest way would be to convert your hexadecimal string to a byte array and use the File.

WriteAllBytes method. Using the StringToByteArray method from this question , you'd do something like this:. Credit: Jared Par. And then use WriteAllBytes to write to the file system. This example reads 6 bytes into a byte array and writes it to another byte array.

It does an XOR operation with the bytes so that the result written to the file is the same as the original starting values. The file is always 6 bytes in size, since it writes at position 0. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow.

Learn more. Write bytes to file Ask Question. Asked 10 years, 5 months ago. Active 2 years, 4 months ago. Viewed k times. NET and C? Improve this question. You can achieve that through the following code. Step 1 Create a new application in.

NET, it could be either web or console application according to your requirement. Skip this step if you want to use the existing project. Step 2 Create a new class with the following code. You can create this class at any common place from where you can access it easily. If your request requires multiple headers you can use Dictionary for the header as we used for parameters. C provides the lock statement for just this purpose:.

When two threads simultaneously contend a lock in this case, locker , one thread waits, or blocks , until the lock becomes available. Code that's protected in such a manner — from indeterminacy in a multithreading context — is called thread-safe. Shared data is the primary cause of complexity and obscure errors in multithreading.

Although often essential, it pays to keep it as simple as possible. You can include a timeout when calling Join , either in milliseconds or as a TimeSpan. It then returns true if the thread ended or false if it timed out.

Sleep pauses the current thread for a specified period:. Framework 4. Yield method does the same thing — except that it relinquishes only to threads running on the same processor. Sleep 0 or Yield is occasionally useful in production code for advanced performance tweaks.

Yield anywhere in your code makes or breaks the program, you almost certainly have a bug. Query databases in a modern query language. Multithreading is managed internally by a thread scheduler, a function the CLR typically delegates to the operating system.

A thread scheduler ensures all active threads are allocated appropriate execution time, and that threads that are waiting or blocked for instance, on an exclusive lock or on user input do not consume CPU time. On a single-processor computer, a thread scheduler performs time-slicing — rapidly switching execution between each of the active threads.

Under Windows, a time-slice is typically in the tens-of-milliseconds region — much larger than the CPU overhead in actually switching context between one thread and another which is typically in the few-microseconds region. On a multi-processor computer, multithreading is implemented with a mixture of time-slicing and genuine concurrency, where different threads run code simultaneously on different CPUs.

A thread is said to be preempted when its execution is interrupted due to an external factor such as time-slicing. A thread is analogous to the operating system process in which your application runs. Just as processes run in parallel on a computer, threads run in parallel within a single process.

Processes are fully isolated from each other; threads have just a limited degree of isolation. In particular, threads share heap memory with other threads running in the same application.

This, in part, is why threading is useful: one thread can fetch data in the background, for instance, while another thread can display the data as it arrives. With technologies such as ASP. NET and WCF, you may be unaware that multithreading is even taking place — unless you access shared data perhaps via static fields without appropriate locking , running afoul of thread safety. Threads also come with strings attached.

The biggest is that multithreading can increase complexity. This applies whether or not the interaction is intentional, and can cause long development cycles and an ongoing susceptibility to intermittent and nonreproducible bugs. For this reason, it pays to keep interaction to a minimum, and to stick to simple and proven designs wherever possible. A good strategy is to encapsulate multithreading logic into reusable classes that can be independently examined and tested.

The Framework itself offers many higher-level threading constructs, which we cover later. Multithreading will not always speed up your application — it can even slow it down if used excessively or inappropriately. Calling Start on the thread then sets it running. The thread continues until its method returns, at which point the thread ends. In this example, thread t executes Go — at much the same time the main thread calls Go.

The result is two near-instant hellos. A thread can be created more conveniently by specifying just a method group — and allowing C to infer the ThreadStart delegate:. With this approach, you can pass in any number of arguments to the method. You can even wrap the entire implementation in a multi-statement lambda:. The limitation of ParameterizedThreadStart is that it accepts only one argument.