Related
The Android API has a very convenient class for this, IconGenerator. Using the IconGenerator in my Android app, I can easily make a marker that:
is a simple rectangle with the color of my choosing.
resizes to hold text of any length.
is NOT an info window - I'd like the marker itself to contain the text as shown in the image below from the android version.
// Android - problem solved with IconGenerator
IconGenerator iconGenerator = new IconGenerator(context);
iconGenerator.setStyle(IconGenerator.STYLE_GREEN); // or any other color
Bitmap iconBitmap = iconGenerator.makeIcon(myString);
Marker m = new MarkerOptions().icon(BitmapDescriptorFactory.fromBitmap(iconBitmap))
.position(myLatLng);
map.addMarker(m); // map is a com.google.android.gms.maps.GoogleMap
Is there a way to do something as simple as this in iOS using Swift?
There has been a recent release of the iOS api that allows "marker customization", but I don't see how to apply it to this use case.
// iOS (Swift) - I don't know how to create the icon as in code above
let marker = GMSMarker(position: myLatLng)
marker.icon = // How can I set to a rectangle with color/text of my choosing?
marker.map = map // map is a GMSMapView
Here is what I have done
let marker = GMSMarker()
// I have taken a pin image which is a custom image
let markerImage = UIImage(named: "mapMarker")!.withRenderingMode(.alwaysTemplate)
//creating a marker view
let markerView = UIImageView(image: markerImage)
//changing the tint color of the image
markerView.tintColor = UIColor.red
marker.position = CLLocationCoordinate2D(latitude: 28.7041, longitude: 77.1025)
marker.iconView = markerView
marker.title = "New Delhi"
marker.snippet = "India"
marker.map = mapView
//comment this line if you don't wish to put a callout bubble
mapView.selectedMarker = marker
The output is
And my marker image was
You can change your color as per your need. Also if you want something in rectange, you can just create a simple small rectangular image and use it like I did above and change the color of your need.
Or if you want a rectangle with text within it, you can just create a small UIView with some label and then convert that UIView in UIImage and can do the same thing.
//function to convert the given UIView into a UIImage
func imageWithView(view:UIView) -> UIImage {
UIGraphicsBeginImageContextWithOptions(view.bounds.size, false, 0.0)
view.layer.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image!
}
Hope it helps!!
Here is what i have done for solving the same issue, that you are facing.
I have added below image in my image assets,
Now i added below method in my code:
-(UIImage*)drawText:(NSString*)text inImage:(UIImage*)image
{
UIFont *font = [UIFont boldSystemFontOfSize:11];
CGSize size = image.size;
UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
[image drawInRect:CGRectMake(0, 0, size.width, size.height)];
CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);
NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
paragraphStyle.alignment = NSTextAlignmentCenter;
NSDictionary *attributes = #{
NSFontAttributeName : font,
NSParagraphStyleAttributeName : paragraphStyle,
NSForegroundColorAttributeName : [UIColor redColor]
};
CGSize textSize = [text sizeWithAttributes:attributes];
CGRect textRect = CGRectMake((rect.size.width-textSize.width)/2, (rect.size.height-textSize.height)/2 - 2, textSize.width, textSize.height);
[text drawInRect:CGRectIntegral(textRect) withAttributes:attributes];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Now, I called this method, while assigning icon to GMSMarker, like this:
marker.icon = [self drawText:#"$33.6" inImage:[UIImage imageNamed:#"icon-marker"]];
It will generate the image icon like below:
Here, I kept the background Image size fixed, as i needed. You can still customize it to adjust it according to text size, as well as multiple lines.
UPDATE
Updated code in Swift:
func drawText(text:NSString, inImage:UIImage) -> UIImage? {
let font = UIFont.systemFont(ofSize: 11)
let size = inImage.size
//UIGraphicsBeginImageContext(size)
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(inImage.size, false, scale)
inImage.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
let style : NSMutableParagraphStyle = NSMutableParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
style.alignment = .center
let attributes:NSDictionary = [ NSAttributedString.Key.font : font, NSAttributedString.Key.paragraphStyle : style, NSAttributedString.Key.foregroundColor : UIColor.black ]
let textSize = text.size(withAttributes: attributes as? [NSAttributedString.Key : Any])
let rect = CGRect(x: 0, y: 0, width: inImage.size.width, height: inImage.size.height)
let textRect = CGRect(x: (rect.size.width - textSize.width)/2, y: (rect.size.height - textSize.height)/2 - 2, width: textSize.width, height: textSize.height)
text.draw(in: textRect.integral, withAttributes: attributes as? [NSAttributedString.Key : Any])
let resultImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return resultImage
}
You can simply add a custom view as marker in Google Map.
let marker = GMSMarker(position: coordinate)
marker.iconView = view // Your Custom view here
You can use imageView (for containing that orange color box) and label (for text) above it
I tried to rewrite Mehul Thakkar answer to Swift 3. Hope it will work for you. But it really easier to make custom view as Dari said.
func drawText(text:NSString, inImage:UIImage) -> UIImage? {
let font = UIFont.systemFont(ofSize: 11)
let size = inImage.size
UIGraphicsBeginImageContext(size)
inImage.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
let style : NSMutableParagraphStyle = NSMutableParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
style.alignment = .center
let attributes:NSDictionary = [ NSFontAttributeName : font, NSParagraphStyleAttributeName : style, NSForegroundColorAttributeName : UIColor.red ]
let textSize = text.size(attributes: attributes as? [String : Any])
let rect = CGRect(x: 0, y: 0, width: inImage.size.width, height: inImage.size.height)
let textRect = CGRect(x: (rect.size.width - textSize.width)/2, y: (rect.size.height - textSize.height)/2 - 2, width: textSize.width, height: textSize.height)
text.draw(in: textRect.integral, withAttributes: attributes as? [String : Any])
let resultImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return resultImage
}
Here a Swift 5 version of Eridana's Swift conversion of Mehul Thakkar's answer.
func drawTextT(text:NSString, inImage:UIImage) -> UIImage? {
let font = UIFont.systemFont(ofSize: 11)
let size = inImage.size
UIGraphicsBeginImageContext(size)
inImage.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
let style : NSMutableParagraphStyle = NSMutableParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
style.alignment = .center
let attributes:NSDictionary = [ NSAttributedString.Key.font : font, NSAttributedString.Key.paragraphStyle : style, NSAttributedString.Key.foregroundColor : UIColor.red ]
//let textSize = text.size(attributes: attributes as? [String : Any])
let textSize = text.size(withAttributes: attributes as? [NSAttributedString.Key : Any] )
let rect = CGRect(x: 0, y: 0, width: inImage.size.width, height: inImage.size.height)
let textRect = CGRect(x: (rect.size.width - textSize.width)/2, y: (rect.size.height - textSize.height)/2 - 2, width: textSize.width, height: textSize.height)
text.draw(in: textRect.integral, withAttributes: attributes as? [NSAttributedString.Key : Any] )
let resultImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return resultImage
}
Simplest way to achieve if you have just 1 image :
marker.icon = #imageLiteral(resourceName: "fault_marker")
1) In latest XCode write marker.icon = "imageLiteral".
2) Double click the dummy image icon appeared just now.
3) select desired image.
//func to get Image view
// Url String :- Your image coming from server
//image :- Background image
func drawImageWithProfilePic(urlString:String, image: UIImage) -> UIImageView {
let imgView = UIImageView(image: image)
imgView.frame = CGRect(x: 0, y: 0, width: 90, height: 90)
let picImgView = UIImageView()
picImgView.sd_setImage(with:URL(string: urlString))
picImgView.frame = CGRect(x: 0, y: 0, width: 40, height: 40)
imgView.addSubview(picImgView)
picImgView.center.x = imgView.center.x
picImgView.center.y = imgView.center.y-10
picImgView.layer.cornerRadius = picImgView.frame.width/2
picImgView.clipsToBounds = true
imgView.setNeedsLayout()
picImgView.setNeedsLayout()
// let newImage = imageWithView(view: imgView)
// return newImage
return imgView
}
//SHOW ON MAP
let marker = GMSMarker()
marker.position = CLLocationCoordinate2D(latitude: Double(lat)!, longitude: Double(long)!)
marker.iconView = self.drawImageWithProfilePic(urlString:getProviderImage,image: UIImage.init(named: "red")!)
Simple and easiest way to change icon. just replace these 3 icon (default marker.png) to your icon (1x,2x,3x).
In Google Cluster there was a problem with marker (icon) change.
My Swift code for capturing a UITableView as an image isn't working when the table is scrolled down. I essentially have the answer in Objective-C but can't seem to make it work in Swift. Currently this is what I have in Swift:
func snapshotOfCell (inputView: UIView) -> UIView {
UIGraphicsBeginImageContextWithOptions(inputView.bounds.size, false, 0.0)
inputView.layer.renderInContext(UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext() as UIImage
UIGraphicsEndImageContext()
let cellSnapshot : UIView = UIImageView(image: image)
cellSnapshot.layer.masksToBounds = false
return cellSnapshot
}
I found this answer but it's in Objective-C:
-(UIImage *) imageWithTableView:(UITableView *)tableView {
UIView *renderedView = tableView;
CGPoint tableContentOffset = tableView.contentOffset;
UIGraphicsBeginImageContextWithOptions(renderedView.bounds.size, renderedView.opaque, 0.0);
CGContextRef contextRef = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(contextRef, 0, -tableContentOffset.y);
[tableView.layer renderInContext:contextRef];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
It seems to fix the scroll problem by using a contentOffset. However, I've been trying to integrate it into my Swift function without success. Anyone good with both Objective-C and Swift? Thanks!
capture whole tableview as a image
UIGraphicsBeginImageContextWithOptions(CGSizeMake(tableView.contentSize.width, tableView.contentSize.height),false, 0.0)
let context = UIGraphicsGetCurrentContext()
let previousFrame = tableView.frame
tableView.frame = CGRectMake(tableView.frame.origin.x, tableView.frame.origin.y, tableView.contentSize.width, tableView.contentSize.height);
tableView.layer.renderInContext(context!)
tableView.frame = previousFrame
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
imageView.image = image;
capture the screenshot of tableview in a scrolled position
let contentOffset = tableView.contentOffset
UIGraphicsBeginImageContextWithOptions(tableView.bounds.size, true, 1)
let context = UIGraphicsGetCurrentContext()
CGContextTranslateCTM(context, 0, -contentOffset.y)
tableView.layer.renderInContext(context!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
imageView.image = image;
Swift 3.0 version for capturing entire tableview based on #Jeyamahesan's answer
UIGraphicsBeginImageContextWithOptions(CGSize(width:tableView.contentSize.width, height:tableView.contentSize.height),false, 0.0)
let context = UIGraphicsGetCurrentContext()
let previousFrame = tableView.frame
tableView.frame = CGRect(x: tableView.frame.origin.x, y: tableView.frame.origin.y, width: tableView.contentSize.width, height: tableView.contentSize.height)
tableView.layer.render(in: context!)
tableView.frame = previousFrame
let image = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
Try this piece of code:
-(UIImage *)screenshot {
UIImage *image = nil;
UIGraphicsBeginImageContextWithOptions(tableView.contentSize, false, 0.0);
{
CGPoint savedContentOffset = tableView.contentOffset;
CGRect savedFrame = tableView.frame;
tableView.contentOffset = CGPointMake(0.0, 0.0);
tableView.frame = CGRectMake(0, 0.0, tableView.contentSize.width, tableView.contentSize.height);
[tableView.layer renderInContext:UIGraphicsGetCurrentContext()];
image = UIGraphicsGetImageFromCurrentImageContext();
tableView.contentOffset = savedContentOffset;
tableView.frame = savedFrame;
}
UIGraphicsEndImageContext();
return image;
}
Happy Coding..!!
Please try this one Its may be help to you
- (UIImage*)buildImage:(UIImage*)image
{
UIGraphicsBeginImageContextWithOptions(image.size, NO, image.scale);
[image drawAtPoint:CGPointZero];
CGFloat scale;
scale = image.size.width / _workingView.frame.size.width;
CGContextScaleCTM(UIGraphicsGetCurrentContext(), scale, scale);
NSLog(#"%f",scale);
[tableView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *tmp = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return tmp;
}
I'm receiving image from a server, then based on a color chosen by the user, the image color will be changed.
I tried the following :
_sketchImageView.image = [_sketchImageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[_sketchImageView setTintColor:color];
i got the opposite of my goal (the white color outside UIImage is colored with the chosen color).
what is going wrong?
i need to do the same in this question,the provided solution doesn't solve my case.
How can I change image tintColor in iOS and WatchKit
Try to generate new image for yourself
UIImage *newImage = [_sketchImageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
UIGraphicsBeginImageContextWithOptions(image.size, NO, newImage.scale);
[yourTintColor set];
[newImage drawInRect:CGRectMake(0, 0, image.size.width, newImage.size.height)];
newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
_sketchImageView.image = newImage;
And use it.
Good luck
======= UPDATE =======
This solution will only change color of all pixel's image.
Example: we have a book image: http://pngimg.com/upload/book_PNG2113.png
And after running above code (exp: TintColor is RED). We have:
SO: how your image is depends on how you designed it
In Swift you can use this extension: [Based on #VietHung's objective-c solution]
Swift 5:
extension UIImage {
func imageWithColor(color: UIColor) -> UIImage? {
var image = withRenderingMode(.alwaysTemplate)
UIGraphicsBeginImageContextWithOptions(size, false, scale)
color.set()
image.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
image = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return image
}
}
Previous Swift version:
extension UIImage {
func imageWithColor(color: UIColor) -> UIImage? {
var image = imageWithRenderingMode(.AlwaysTemplate)
UIGraphicsBeginImageContextWithOptions(size, false, scale)
color.set()
image.drawInRect(CGRect(x: 0, y: 0, width: size.width, height: size.height))
image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
In swift 2.0 you can use this
let image = UIImage(named:"your image name")?.imageWithRenderingMode(.AlwaysTemplate)
let yourimageView.tintColor = UIColor.redColor()
yourimageView.image = image
In swift 3.0 you can use this
let image = UIImage(named:"your image name")?.withRenderingMode(.alwaysTemplate)
let yourimageView.tintColor = UIColor.red
yourimageView.image = image
Try something like this
UIImage *originalImage = _sketchImageView.image
UIImage *newImage = [originalImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,50,50)]; // your image size
imageView.tintColor = [UIColor redColor]; // or whatever color that has been selected
imageView.image = newImage;
_sketchImageView.image = imageView.image;
Hope this helps.
In Swift 3.0 you can use this extension: [Based on #VietHung's objective-c solution]
extension UIImage {
func imageWithColor(_ color: UIColor) -> UIImage? {
var image = imageWithRenderingMode(.alwaysTemplate)
UIGraphicsBeginImageContextWithOptions(size, false, scale)
color.set()
image.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
For Swift 3.0, I made a custom subclass of UIImageView called TintedUIImageView. Now the image uses whatever tint color is set in interface builder or code
class TintedUIImageView: UIImageView {
override func awakeFromNib() {
if let image = self.image {
self.image = image.withRenderingMode(.alwaysTemplate)
}
}
}
You can try:
_sketchImageView.image = [self imageNamed:#"imageName" withColor:[UIColor blackColor]];
- (UIImage *)imageNamed:(NSString *)name withColor:(UIColor *)color
{
// load the image
//NSString *name = #"badge.png";
UIImage *img = [UIImage imageNamed:name];
// begin a new image context, to draw our colored image onto
UIGraphicsBeginImageContext(img.size);
// get a reference to that context we created
CGContextRef context = UIGraphicsGetCurrentContext();
// set the fill color
[color setFill];
// translate/flip the graphics context (for transforming from CG* coords to UI* coords
CGContextTranslateCTM(context, 0, img.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
// set the blend mode to color burn, and the original image
CGContextSetBlendMode(context, kCGBlendModeColorBurn);
CGRect rect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, rect, img.CGImage);
// set a mask that matches the shape of the image, then draw (color burn) a colored rectangle
CGContextClipToMask(context, rect, img.CGImage);
CGContextAddRect(context, rect);
CGContextDrawPath(context,kCGPathFill);
// generate a new UIImage from the graphics context we drew onto
UIImage *coloredImg = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//return the color-burned image
return coloredImg;
}
Try setting the tint color on the superview of the image view. E.g. [self.view setTintColor:color];
in Swift 4 you can simply make an extension like that:
import UIKit
extension UIImageView {
func tintImageColor(color: UIColor) {
guard let image = image else { return }
self.image = image.withRenderingMode(UIImageRenderingMode.alwaysTemplate)
self.tintColor = color
}
}
- SWIFT 4
extension UIImage {
func imageWithColor(_ color: UIColor) -> UIImage? {
var image: UIImage? = withRenderingMode(.alwaysTemplate)
UIGraphicsBeginImageContextWithOptions(size, false, scale)
color.set()
image?.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
Here's how I apply and use tints in IOS 9 with Swift.
//apply a color to an image
//ref - http://stackoverflow.com/questions/28427935/how-can-i-change-image-tintcolor
//ref - https://www.captechconsulting.com/blogs/ios-7-tutorial-series-tint-color-and-easy-app-theming
func getTintedImage() -> UIImageView {
var image : UIImage;
var imageView : UIImageView;
image = UIImage(named: "someAsset")!;
let size : CGSize = image.size;
let frame : CGRect = CGRectMake((UIScreen.mainScreen().bounds.width-86)/2, 600, size.width, size.height);
let redCover : UIView = UIView(frame: frame);
redCover.backgroundColor = UIColor.redColor();
redCover.layer.opacity = 0.75;
imageView = UIImageView();
imageView.image = image.imageWithRenderingMode(UIImageRenderingMode.Automatic);
imageView.addSubview(redCover);
return imageView;
}
One thing you can do is, just add your images to Assets folder in XCode and then change the rendering mode to Template Image, so whenever you change the tint color of UIImageView, it will automatically makes change to image.
Check this link out -> https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiM0YXO0ejTAhUIQ48KHfGpBpgQjRwIBw&url=https%3A%2F%2Fkrakendev.io%2Fblog%2F4-xcode-asset-catalog-secrets-you-need-to-know&psig=AFQjCNGnAzVn92pCqM8612o1R0J9q1y7cw&ust=1494619445516498
let image = UIImage(named: "i m a g e n a m e")?.withRenderingMode(.alwaysTemplate)
imageView.tintColor = UIColor.white // Change to require color
imageView.image = image
Try this
iOS 13.4 and above
UIImage *image = [UIImage imageNamed:#"placeHolderIcon"];
[image imageWithTintColor:[UIColor whiteColor] renderingMode: UIImageRenderingModeAlwaysTemplate];
How to create a circular image with border (UIGraphics)?
P.S. I need to draw a picture.
code in viewDidLoad:
NSURL *url2 = [NSURL URLWithString:#"http://images.ak.instagram.com/profiles/profile_55758514_75sq_1399309159.jpg"];
NSData *data2 = [NSData dataWithContentsOfURL:url2];
UIImage *profileImg = [UIImage imageWithData:data2];
UIGraphicsEndImageContext();
// Create image context with the size of the background image.
UIGraphicsBeginImageContext(profileImg.size);
[profileImg drawInRect:CGRectMake(0, 0, profileImg.size.width, profileImg.size.height)];
// Get the newly created image.
UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
// Release the context.
UIGraphicsEndImageContext();
// Set the newly created image to the imageView.
self.imageView.image = result;
It sounds like you want to clip the image to a circle. Here's an example:
static UIImage *circularImageWithImage(UIImage *inputImage,
UIColor *borderColor, CGFloat borderWidth)
{
CGRect rect = (CGRect){ .origin=CGPointZero, .size=inputImage.size };
UIGraphicsBeginImageContextWithOptions(rect.size, NO, inputImage.scale); {
// Fill the entire circle with the border color.
[borderColor setFill];
[[UIBezierPath bezierPathWithOvalInRect:rect] fill];
// Clip to the interior of the circle (inside the border).
CGRect interiorBox = CGRectInset(rect, borderWidth, borderWidth);
UIBezierPath *interior = [UIBezierPath bezierPathWithOvalInRect:interiorBox];
[interior addClip];
[inputImage drawInRect:rect];
}
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return outputImage;
}
Result:
Have you tried this ?
self.imageView.layer.borderColor = [UIColor greenColor].CGColor;
self.imageView.layer.borderWidth = 1.f;
You'll also need
self.imageView.layer.corderRadius = self.imageView.frame.size.width/2;
self.imageView.clipsToBounds = YES;
Swift 4 version
extension UIImage {
func circularImageWithBorderOf(color: UIColor, diameter: CGFloat, boderWidth:CGFloat) -> UIImage {
let aRect = CGRect.init(x: 0, y: 0, width: diameter, height: diameter)
UIGraphicsBeginImageContextWithOptions(aRect.size, false, self.scale)
color.setFill()
UIBezierPath.init(ovalIn: aRect).fill()
let anInteriorRect = CGRect.init(x: boderWidth, y: boderWidth, width: diameter-2*boderWidth, height: diameter-2*boderWidth)
UIBezierPath.init(ovalIn: anInteriorRect).addClip()
self.draw(in: anInteriorRect)
let anImg = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return anImg
}
}
I've looked around everywhere, but I can't find a way to do this. I need to create a black UIImage of a certain width and height (The width and height change, so I can't just create a black box and then load it into a UIImage). Is there some way to make a CGRect and then convert it to a UIImage? Or is there some other way to make a simple black box?
Depending on your situation, you could probably just use a UIView with its backgroundColor set to [UIColor blackColor]. Also, if the image is solidly-colored, you don't need an image that's actually the dimensions you want to display it at; you can just scale a 1x1 pixel image to fill the necessary space (e.g., by setting the contentMode of a UIImageView to UIViewContentModeScaleToFill).
Having said that, it may be instructive to see how to actually generate such an image:
Objective-C
CGSize imageSize = CGSizeMake(64, 64);
UIColor *fillColor = [UIColor blackColor];
UIGraphicsBeginImageContextWithOptions(imageSize, YES, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
[fillColor setFill];
CGContextFillRect(context, CGRectMake(0, 0, imageSize.width, imageSize.height));
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Swift
let imageSize = CGSize(width: 420, height: 120)
let color: UIColor = .black
UIGraphicsBeginImageContextWithOptions(imageSize, true, 0)
let context = UIGraphicsGetCurrentContext()!
color.setFill()
context.fill(CGRect(x: 0, y: 0, width: imageSize.width, height: imageSize.height))
let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
UIGraphicsBeginImageContextWithOptions(CGSizeMake(w,h), NO, 0);
UIBezierPath* p =
[UIBezierPath bezierPathWithRect:CGRectMake(0,0,w,h)];
[[UIColor blackColor] setFill];
[p fill];
UIImage* im = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Now im is the image.
That code comes almost unchanged from this section of my book: http://www.apeth.com/iOSBook/ch15.html#_graphics_contexts
Swift 3:
func uiImage(from color:UIColor?, size:CGSize) -> UIImage? {
UIGraphicsBeginImageContextWithOptions(size, true, 0)
defer {
UIGraphicsEndImageContext()
}
let context = UIGraphicsGetCurrentContext()
color?.setFill()
context?.fill(CGRect.init(x: 0, y: 0, width: size.width, height: size.height))
return UIGraphicsGetImageFromCurrentImageContext()
}
Like this
let image = UIGraphicsImageRenderer(size: bounds.size).image { _ in
UIColor.black.setFill()
UIRectFill(bounds)
}
As quoted in this WWDC vid
There's another function that's older; UIGraphicsBeginImageContext. But please, don't use that.
Here is an example that creates a black UIImage that is 1920x1080 by creating it from a CGImage created from a CIImage:
let frame = CGRect(origin: CGPoint(x: 0, y: 0), size: CGSize(width: 1920, height: 1080))
let cgImage = CIContext().createCGImage(CIImage(color: .black()), from: frame)!
let uiImage = UIImage(cgImage: cgImage)