Introduction
As you might know, I have always been fascinated with Wallpapers and photos. What you might not know is that I appreciate good art as well, seeing the fact that my wife is quite good at painting and creating things out of nothing.
I have a huge collection of wallpapers. Some of you might remember this old dinosaur project of mine, which I still use successfully to change my desktop backgrounds. Because of the tedious nature of collecting new wallpapers, I have decided to make a little tool to do all the hard work for me. With this article I will demonstrate how to download images from a webpage. Note: some pictures are copyrighted, and must not be used in any way. I am not advocating that. I am using pictures from websites that provide them for free.
Anyways, enough about me, let us get started with our little project
Design
Fire up Visual Studio 2012 and choose your desired programming language. I will illustrate both VB.NET as well as C#.
Design your form to resemble Figure 1.
Figure 1 – Our Design
Code
Not much coding needed from our side. Let’s start with importing the Namespaces.
VB.NET
Imports System.IO 'File Functions
C#
using System.IO; //For File Functions
Now let’s handle the navigation button that will enable us to navigate to a site:
VB.NET
Private Sub btnIDGo_Click(sender As Object, e As EventArgs) Handles btnIDGo.Click wbID.Navigate(txtIDURL.Text) 'Navigate To URL End Sub
C#
private void btnIDGo_Click(object sender, EventArgs e) { wbID.Navigate(txtIDURL.Text); //Navigate To URL }
The above code segment instructs the WebBrowser Control to navigate to the entered site. This also assumes your WebBrowser Control was named wbID as was the case with mine.
Now the fun starts!
Add the next code segment:
VB.NET
Private Sub btnIDGet_Click(sender As Object, e As EventArgs) Handles btnIDGet.Click Dim wcObj As New System.Net.WebClient() 'Create New Web Client Object Dim hecImages As HtmlElementCollection = wbID.Document.GetElementsByTagName("img") 'Browse Through HTML Tags Dim strWebTitle As String 'Web Page Title Dim strPath1 As String 'Folder Path Dim strPath2 As String 'Sub Folder Path strWebTitle = Me.wbID.DocumentTitle 'Obtain Web Page Title strPath1 = "c:\" & strWebTitle 'Create Folder Named Web Page Title strPath2 = strPath1 & "\Images" 'Create Images Sub Folder Dim diTitle As DirectoryInfo = Directory.CreateDirectory(strPath1) Dim diImages As DirectoryInfo = Directory.CreateDirectory(strPath2) For i As Integer = 0 To hecImages.Count - 1 'Loop Through All IMG Elements Found 'Download Image(s) To Specified Path wcObj.DownloadFile(hecImages(i).GetAttribute("src"), strPath1 & "\images\" & i.ToString() & ".jpg") Next End Sub
C#
private void btnIDGet_Click(object sender, EventArgs e) { System.Net.WebClient wcObj = new System.Net.WebClient(); //Create New Web Client Object HtmlElementCollection hecImages = wbID.Document.GetElementsByTagName("img"); //Browse Through HTML Tags string strWebTitle; //Web Page Title string strPath1; //Folder Path string strPath2; //Sub Folder Path strWebTitle = this.wbID.DocumentTitle; //Obtain Web Page Title strPath1 = @"c:\" + strWebTitle; //Create Folder Named Web Page Title strPath2 = strPath1 + "\\Images"; //Create Images Sub Folder DirectoryInfo diTitle = Directory.CreateDirectory(strPath1); DirectoryInfo diImages = Directory.CreateDirectory(strPath2); for (int i = 0; i < hecImages.Count; i++) //Loop Through All IMG Elements Found { //Download Image(s) To Specified Path wcObj.DownloadFile(hecImages[i].GetAttribute("src"), strPath1 + "\\images\\" + i.ToString() + ".jpg"); } }
We create a webclient object to assist us later in downloading the images. We then create an HTMLElementCollection object, which helps us identify all Image tags on the webpage. If you do not have a basic understanding of HTML, I suggest you have a look here.
We store the Webpage’s title and create a folder on C:\ with the same name. Inside this folder we create a subfolder named Images. This is where we will download our pictures to.
The fun part here is the loop. We use a for loop to loop through all of the images found and save them via the DownloadFile method of the WebClient object. We find the image’s location through the HTML IMG Tag’s SRC attribute. Voila! Quick and simple.
Conclusion
Although this is but a small tool, its possibilities are endless. I am including the Source files just in case you missed something. Until next time, cheers from a lazy Hannes!