Therefore the code you have quoted is obviously not going to work. For conversion help, see the cgimage property orientation overview. Objectivec what is the way to properly set the height and. Does anyone know how to convert a uiimage to a base64 string. Nsstring nsdata nsstring nsstring astring nsstring alloc initwithdata. Mar 12, 20 convert nsdata to nsstring in the previous post i wrote a few lines of code to convert an nsstring object to an nsdata object. Creates and returns an image object that uses the specified image data. Resize images and save thumbnails xamarin community forums. Passing data between view controllers with messageboxconcept pdf creation in ios. You embedded the contentsofdirectoryatpath api inside a docatch block to handle any potential errors it may throw. Objectivec objectivec how to put black transparent.
Objective c save uiimage as a bmp file stack overflow. To download the file and turn it into nsdata we need an nsurlrequest. In this post ill do the opposite, putting the conversion into the context how to print an nsdata object to the debugging console. In order to get it back, you can use the nsdata class to get the contents of the file at that url. You can print it by assigning to the printingitem property the uiimage or a photo. Apple developer forums xcode objectivec modify jpeg metadata given nsdata 80 views 5.
Swift, the swift logo, swift playgrounds, xcode, instruments, cocoa touch, touch id, airdrop, ibeacon, iphone, ipad, safari, app store. The method above will first fetch all the content inside the imagepicker folder. Generating pdf documents programmatically in ios sentia blog. I have uitableview that lists social media posts with images in them. The examples below show variations on the layers contentsgravity property. It treats in this tutorial, we will learn how to convert images and pdf to base64 string in swift. You can serialize the object to a byte array, then use that to create the nsdata object and get the byte array back out when you need it again you could also serialize the object to a string with for example, then create the nsdata from the string. If youve generated an image using core graphics, or perhaps rendered part of your layout, you might want to save that out as either a png or a jpeg. Good morning all, i am using swift new for me and core data i am trying to fetch my stored uiimage from core data the following way. I dont mind too much the change in title, but the lack of a. Adds to the end of the receiver the characters of a given string. Due to the loop, the system might never get a chance to free the memory not needed anymore.
Image objects are immutable, so you always create them from existing image data. Loadfromdatadata always returns null and that was working on ios 8. This can be useful if youd like to save it in core data. Im trying to send a pdf using a uiactivityviewcontroller.
Multiply the size values by the value in the scale property to get the pixel dimensions of the image. Sep 16, 2014 swift create image instance with image name from bundle var image. Description of the object, the objectivec version of tostring. We also need a url to download from, and the location of the users documents directory. Stack overflow for teams is a private, secure spot for you and your coworkers to find and share information. You can add an image to a views layer simply by using its contents property myview.
In this post ill do the opposite, putting the conversion into the context how to print an nsdata object to the debugging console by default, when you print an nsdata object to the console using nslog, the output will be in hex, it will look something like the following. Uiprintinteractioncontroller class uikit microsoft docs. Some frameworks describe image orientation using the cgimage property orientation type or the raw tiffexif numeric values that type defines symbols for. Ive spent hours figuring out which way to store the data. Loading many large images that way can cause low memory warnings which can lead the app to be terminated. You can store a uiimage or an nsimage on mac as raw data. String get existing pdf reference let pdf cgpdfdocumentcreatewithurlnsurlfileurlwithpath. Listing 1 illustrates the correct and incorrect ways. Pdf nsnumber nsnumber nsdata nsdata nsdata stringdouble. So far everything works fine using a fairly basic approach but the one issue i have is that when i select the send by mail option, the pdfs file name is attachment1 rather than calculation. The method imagenamed caches the images contents to memory.
If bordersize is nonzero, a transparent border of the given size will also be added. Here is how you can start creating your own pdf document. Encoding convert the image to nsdata first let imagedata. Nsdata uiimagejpegrepresentation uiimage image, cgfloat compressionquality. This function may return nil if the image has no data or if the underlying cgimage ref contains data in an unsupported bitmap format. Here is the correct method to convert a cvmat to a uiimage every other implementation ive seen including opencvs documentation is incorrect. This value reflects the logical size of the image and takes the images current orientation into account. When i save to core data the nslog looks like this. Then, you just loop over the images, extract them as nsdata types, transform to uiimage types then store to the images array you embedded the contentsofdirectoryatpath api inside a docatch block to handle. Howvere i ran into objectiveconly code snippets which are not clear to me. Nsdata converting nsdata to other types essential ios.
Swift create image instance with image name from bundle var image. Objectivec what is the way to properly set the height. The second one returns a new nsstring which is a concatenation of the receiver and the parameter. I drag and drop the uiimageview in the uitableviewcell and set the height and width visually i am using storyboards. Saving an array of uiimage objects objective c youtube. You use image objects to represent image data of all kinds, and the uiimage class is capable of managing data for all image formats supported by the underlying platform.
Hi readers,this blog includes the concept of converting nsdata to uiimage with the help of a very simple example. Swift core data cast nsdata to uiimage apple developer forums. The only way to determine their equality is to use the isequal. Use the following line to import the necessary methods. Provide me any good code example of converting nsdata to nsstring. Initializes and returns the image object with the specified data and scale factor. Jan 31, 2016 then, you just loop over the images, extract them as nsdata types, transform to uiimage types then store to the images array.
Objectivec objectivec how to put black transparent on. How to convert a uiimage into nsdata ios dev diary. Nsdictionary pdf nsdata nsdata nsdata stringdouble. Converting nsdata to nsstring in objective c stack overflow. In the previous post i wrote a few lines of code to convert an nsstring object to an nsdata object. Converting a pdf image to nsdata for stack overflow. While its not in swift but objective c, i think this link does exactly what you are looking for. The motivation for this was to enable the easy use of scaleable vector assets in ios apps. To force the system to do so, wrap the inside of your loop in an autoreleasepool, like this. The motivation for this was to enable the easy use of scaleable vector assets in ios apps usage. Fromstring, but those functions do entirely different things.
Jun 08, 2016 ive spent hours figuring out which way to store the data. Instead, we can use nsdata to retrieve the data and use its method writetofile to writetourl. Nsdata can be represented as hexadecimal string, similar to what it outputs in its description method swift. That call to getdocumentsdirectory is a little helper. I am using vector graphics in my application and want to store.
The uiimage class automatically handles the transform necessary to present an image in the correct display orientation according to its orientation metadata, so an image objects image orientation property simply indicates which transform was applied. A data object containing the jpeg data, or nil if there was a problem generating the data. This is because the uiimage is smaller than the uiview so it is being scaled to fill the view, which is the default it you dont specify anything else. Uitableviewcell shows the wrong image while images load. Converting a pdf image to nsdata for ios xcode parseplatform nsdata. Convert nsattributedstring to uiimage ios tutorial. Learn more converting nsdata to nsstring in objective c. However, the underlying numeric values of that type are incompatible with uiimage.
Returns the data for the specified image in png format. Control file name of uiimage send with uiactivityviewcontroller. The first one mutates the existing nsmutablestring. The contentsofdirectoryatpath method will return an array of strings reflecting the files names. With reference to rendering a cgpdfpage into a uiimage and davids thx. Nsdata can be represented as hexadecimal string, similar to what it outputs in its description method swift extension nsdata func hexstring string return unsafebufferpointer start. Pdf which is the name that i give the file i dont mind too much the change in title, but the lack of a. The image objects you create may be different from each other, even when you initialize them with the same cached image data. You will need to remember the url where you saved the image pdf that you are storing. How to convert nsdata to nsstring or vice versa in. So, in this tutorial ive talked about saving an array of uiimage objects as nsdata, and retrieve them by. Uiimagejpegrepresentation uikit apple developer documentation. November 17, 20 ios development core data, nsvaluetransformer, uiimage jay versluis.
If you are using a image on different sizes and resizing each time it will degrade your app performance. Browse other questions tagged objective c c bitmap uiimage or ask your own question. Swift core data cast nsdata to uiimage 3673 views 2 replies. Nsmutablearray assuming data is a valid nsdata object. Objective c nsdata data uiimagepngrepresentationself. Solution is dont resize them just use button in place of imageview.
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