I have a directory with .png images which I display in a third party combobox of my c# program. So the user is able to choose one of this images using the combo box. Basic code used:
Bitmap thump = new Bitmap(<path>);
ComboItem item = new ComboItem();
item.Image = thump;
MyComboBox.Items.Add(item);
Now I would like to update one of this images at runtime. Unfortunately I can't delete the old image because it is still opened in my program, so somehow I either need to close it or open it in a way that does not keep the image in use by my program. The changes to the bitmap are not done in my program, I just pass the path of the dirctory to another program which saves the bitmap there (but fails at the moment because it can't delete the old bitmap).
I guess this is a simple problem but I could not find a solution here or on the internet.
First read the file to memory, then create the Bitmap using that data.
var m = new MemoryStream(File.ReadAllBytes(filename));
Bitmap thump = (Bitmap)Bitmap.FromStream(m);
Related
I have a pdf file created with itextsharp with images in the file. I would like to put a hyperlink in the file that if you pick the picture it will open that picture in a picture viewer. I can set a hyperlink to a web address but have no idea how to get it to open a file. Below is the code, yes I know that c:\test.jpg is a bad hardcoded file name but it is just a test. When you click the picture it does nothing but I have no idea how to tell it what to do.
iTextSharp.text.Image pic =TextSharp.text.Image.GetInstance(comment.examplePic);
pic.ScaleToFit(200f, 200f);
Chunk cImage = new Chunk(pic, 0, 0, false);
Anchor anchor = new Anchor(cImage);
anchor.Reference = "c:\\test.jpg";
doc.Add(pic);
doc.Add(anchor);
A PDF is self-contained. This means that all the resources needed to show the PDF are (usually) stored inside the PDF (exceptions are for instance fonts that can be retrieved from the operating system).
When you have an image that is shown on a PDF page, the bytes of that image are stored in what we call an Image XObject. An XObject is an object that is external to the page, but that is stored as a separate object inside the PDF file.
You are asking to serve the image bytes stored inside this separate object to a viewer on the operating system. This is impossible. I don't know of any viewer that can take those bytes and somehow forward them to an image viewer.
I can think of three possible workarounds. I don't know if any of these workarounds is acceptable to you.
1. Serve the image online
You could put the image on a server and use the code you have in your snippet to link to that online image. Of course: this will only work if the person viewing the document is online and clicks OK when his viewer asks him if it's OK to link to a resources on the internet.
2. Serve the image as an annotation
In this case, you create an annotation for which you create an appearance that renders that same image XObject in the annotation layer (all annotations are shown on top of the page content). You can easily change the visibility status of an annotation to make it invisible (in your case, this would be the default status) or visible (in your case, this would be triggered by a JavaScript action when clicking the link).
There's an example of such an annotation here: Advertisement. If you open advertisement.pdf, you see an image with a button that says "Close this advertisement". Once you click that, the status of the annotation will be changed to invisible. You could do something similar, but the other way round: click a link to make it visible instead of invisible.
This solution doesn't depend on an external viewer, the image is shown in the PDF viewer.
3. Add the image as optional content
Starting with PDF 1.5, PDF supports optional content. See for instance the OptionalContentExample. In this example, we have some questions and answers, but the answers are not visible by default. See layer_actions.pdf. There are links "on / off / toggle" to make the answers visible or invisible.
You could do the same with images: you could add them to a layer that is invisible by default, but that can be made visible if somebody clicks a link. However: this requires a viewer that supports OCG (optional content groups) and the actions to change the status of these OCGs. For instance: if you would try the layer_actions.pdf example in the PDF viewer in Chrome, it won't work, but if you download the PDF and open it in Adobe Reader, you'll see the behavior I described.
Summarized:
You are asking something that is impossible, but there are workarounds. Please post another question if you have chosen a workaround and you don't succeed in making that workaround word (but please take into account that not all viewers support every workaround).
no offence but too much knowledge sometimes makes you ignorant of small things.
simple solution to this problem is here
http://kuujinbo.info/iTextSharp/imageAnchor.aspx
sample code that i implemented works like charm
PdfPCell p1 = new PdfPCell();
p1 = new PdfPCell();
p1.Padding = 0;
p1.Border = 0;
PdfPTable nav = new PdfPTable(1);
nav.WidthPercentage = 100;
nav.SpacingAfter = 12;
navbarImg.Annotation= new Annotation(0, 0, 0, 0, ur);
p1.Image = navbarImg;
nav.AddCell(p1);
_doc.Add(nav);
I need to change the background image at runtime, based on which RadioButton the user clicks. I'm doing this in a WPF project in Visual Studio, and I need to put the code in the Checked event in the xaml.cs file
I have an Image control called imgBackground, with 6 images in its Source collection, which are listed in an Images folder in the Solution Explorer.
I've tried:
this.imgBackground.Source = "filename.jpg";
both with and without the quotes, and with various paths (I've tried too many different variations to list them all here) and nothing works - everything I've tried just gives an error in the editor, before I even try to build and run anything (the error given varies depending on what I'm trying at the time).
If you are using relative paths as filenames like
this.imgBackground.Source = "filename.jpg";
then these files must be in the same directory as the .exe of your program is.
One workaround would be to use absolute paths like
this.imgBackground.Source = #"C:\MyFolder\MyProject\filename.jpg";
Or, even further use the packaging mechanism of WPF or pack your images as resources into your assembly. Look at this thread.
EDIT:
For your clarification:
The Source-property demands an System.Windows.Media.ImageSource-object, which you must provide.
Do it like this:
BitmapImage bi3 = new BitmapImage();
bi3.BeginInit();
bi3.UriSource = new Uri("filename.jpg", UriKind.Relative);
bi3.EndInit();
this.imgBackground.Source = bi3;
Please refer to this documentation here.
I m scanning image in a form i want to save the image with out user interaction in C# can any one help..
string chktemp = #"C:\"+pic+".tif";
Bitmap bm= new Bitmap(from file);//Here it is asking already saved file with out this i want to save just now scanned image from form
bm.Save(chktemp);
Use IO to check if the current file exists, and if so delete it first.
See: System.IO documentation
File.Exists
http://msdn.microsoft.com/en-us/library/system.io.file.exists.aspx
File.Delete
http://msdn.microsoft.com/en-us/library/system.io.file.delete.aspx
Load the Image File to Stream ,than you can Create Bitmap from Stream ,which will close the File Read Operation in source Image .
I am looking for ways to save the output of a Chart control as an image on the hard drive. Is it possible in SL? as I am not sure so thought of putting a question here..
Thanks...
have a look here: Can I programmatically capture snapshot of a Silverlight User Control?
You can simply take a screenshot of your chart. If you want to put in on the HD with silverlight you need to open a SaveFileDialog. Then it is possible.
EDIT: If you want to save it in different formats use ImageTools. http://imagetools.codeplex.com/. If you use ImageTools you can get a stream like this:
var editBitmap = new WriteableBitmap(1024, 786);
editBitmap = new WriteableBitmap((int)(this.RenderSize.Width), (int)(this.RenderSize.Height));
editBitmap.Render(this, new MatrixTransform());
editBitmap.Invalidate();
var myImage = editBitmap.ToImage();
Stream stream = myImage.ToStreamByExtension("png");
Hope this helps.
BR,
TJ
I'm working on an older project, updating it. Part of the program has a toolstrip with many buttons on it, each with an image. I found that the images are stored in a Base64 encoded imagestream in the resx for the form and accessed as such:
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
...
this.imageList1 = new System.Windows.Forms.ImageList(this.components);
...
this.toolStrip1.ImageList = this.imageList1;
...
this.imageList1.ImageStream = ((System.Windows.Forms.ImageListStreamer)(resources.GetObject("imageList1.ImageStream")));
...
this.toolStripButton1.ImageIndex = 0; //There are 41 images, so this can be between 0 and 40
I need to add another button with a new image. How can I add an image to this stream?
I cannot use the designer, as it crashes as soon as I load the form (I believe because it uses a custom component with unsafe code).
I could always just add a new image resource separate from the stream, but that would make that one button different and thus it would create problems with consistency, causing upkeep problems later. So I'm wondering if there is any way for me to edit the imagestream. I can access the raw base64 string, but I have no idea where to go from here.
Create another form.
Add an ImageList component.
Add an arbitrary image in order to generate an "imagestream".
Open old resx and copy the "value" element.
Open new resx and paste value element.
Open new form.
Add images as needed.
Save new form.
Open new form's resx file.
Copy value element.
Open old form's resx file.
Paste in new value element.
I found a way to do this using code:
imageList1.Images.Add( NEWIMAGE );
ResXResourceWriter writer = new ResXResourceWriter("newresource.resx");
writer.AddResource("imageList1.ImageStream",imageList1.ImageStream);
writer.Generate();
writer.Close();
writer.Dispose();
The code will write the updated ImageStream to the new resource file. I can then copy it to my current resource file.