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