I would like to change the color of an image that I have placed as a button in my navBar. The code I am using to create the image/button is:
UIImage *btnGoImage = [UIImage imageNamed:#"settings_cog.png"];
UIButton *btnGoPre = [UIButton buttonWithType:UIButtonTypeCustom];
btnGoPre.bounds = CGRectMake( 0, 0, 30, 30 );
[btnGoPre setImage:btnGoImage forState:UIControlStateNormal];
[btnGoPre addTarget:self action:#selector(loginAction)
forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *btnGo = [[UIBarButtonItem alloc] initWithCustomView:btnGoPre];
If I wanted to change the image to red (it is currently gray). How would I do this? Thanks!
this is the method that will help to change the color of your image you need to pass the image and color as your input variables and it will return the output image
-(UIImage *)imageNamed:(NSString *)name withColor:(UIColor *)color
{
// load the image
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;
}
and here is the example how you can call this method
yourImageView.image = [self imageNamed:#"yourImageName" withColor:[UIColor orangeColor]];
Try a UIBarButtonItem class tintColor property.
Related
I building app open Camera by using UIImagePickerController but I want before take picture, I can adjust intesity of LED. I think if can add UISlider to UIImagePickerController to adjust intesity LED before take picture is good but I don't know how to add UISlider to UIImagePickerController.
Do you have ideas?
CGFloat brightness = 0.5;
UIGraphicsBeginImageContext(image.size);
CGRect imageRect = CGRectMake(0, 0, image.size.width, image.size.height);
CGContextRef context = UIGraphicsGetCurrentContext();
// Original image
[image drawInRect:imageRect];
// Brightness overlay
CGContextSetFillColorWithColor(context, [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:brightness].CGColor);
CGContextAddRect(context, imageRect);
CGContextFillPath(context);
UIImage* resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
`You can change brightness overlay color to get proper results.`
For example, in the iOS toolbar, you drag in your own .png which is opaque black and transparent, and it automatically adds the iOS blue gloss.
However, I'd like to know how to do this yourself, but just solid colors will do.
For example, if you had this image:
What would you do to make that entire solid, pink, or blue, or grey? I want to cut down on the number of versions of .png's I save in my app by colorizing them with code.
Thank you!
This should do it for you:
- (UIImage *)colorImage:(UIImage *)origImage withColor:(UIColor *)color
{
UIGraphicsBeginImageContextWithOptions(origImage.size, YES, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, (CGRect){ {0,0}, origImage.size} );
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, origImage.size.height);
CGContextConcatCTM(context, flipVertical);
CGContextDrawImage(context, (CGRect){ pt, origImage.size }, [origImage CGImage]);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
As of iOS 7 you can now colour black (greyscale) / transparent images with a single colour like so
UIImage *image = [UIImage imageNamed:#"myImage.png"];
UIImageView *imageView = [[UIImageView alloc]initWithImage:[image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]];
imageView.tintColor = [UIColor redColor];
I need to draw a rect filled with color and its border...
the rect is filled with color properly but the outside border is partially drawn, just the right side of the rect is drawn!
The generated UIImage is going to be used in a UITableViewCell's imageView.
- (UIImage *)legendItemWithColor:(UIColor *)color
{
UIGraphicsBeginImageContext(self.view.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect outside = CGRectMake(128, 128, 128, 128);
CGRect legend = CGRectInset(outside, 1, 1);
NSLog(#"Outside: %#", NSStringFromCGRect(outside));
NSLog(#"Legend: %#", NSStringFromCGRect(legend));
CGContextSetFillColorWithColor(context, color.CGColor);
CGContextFillRect(context, legend);
CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor);
CGContextStrokeRect(context, outside);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsPopContext();
return img;
}
The problem is when you pass self.view.frame.size to UIGraphicsBeginImageContext() and then use drawn rectangle in array, it is downscaled and the border is obfuscated. Try to pass only the size you need so, i.e. CGSizeMake(2*128+128+2,2*128+128+2). Then it displays ok
I can use the following code to create image from UIView.
However the same code won't capture the text of UILabel.(it captures label's background color though)
How can I create image of UILabel with text?
CGSize size = view.bounds.size;
CGContextRef context = CreateARGBBitmapContext(size);
CGContextTranslateCTM(context, 0, size.height);
CGContextScaleCTM(context, 1.0, -1.0);
[view.layer renderInContext: context];
CGImageRef imageRef = CGBitmapContextCreateImage(context);
UIImage* img = [UIImage imageWithCGImage: imageRef];
CGImageRelease(imageRef);
CGContextRelease(context);
In the viewcontroller, select the label and on the right side, you should be able to set an image to the label.
Also, you might be having a problem with layers... [self addChild: label z:0 tag:1];
Just in case you don't know, z:0 means the layer. So something with z:-1 would be below a picture with z:0. You could just set the text ontop of the label
I need to darken a UIImageView when it gets touched, almost exactly like icons on the springboard (home screen).
Should I be added UIView with a 0.5 alpha and black background. This seems clumsy. Should I be using Layers or something (CALayers).
I would let a UIImageView handle the actual drawing of the image, but toggle the image to one that's been darkened in advance. Here's some code I've used to generate darkened images with alpha maintained:
+ (UIImage *)darkenImage:(UIImage *)image toLevel:(CGFloat)level
{
// Create a temporary view to act as a darkening layer
CGRect frame = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
UIView *tempView = [[UIView alloc] initWithFrame:frame];
tempView.backgroundColor = [UIColor blackColor];
tempView.alpha = level;
// Draw the image into a new graphics context
UIGraphicsBeginImageContext(frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[image drawInRect:frame];
// Flip the context vertically so we can draw the dark layer via a mask that
// aligns with the image's alpha pixels (Quartz uses flipped coordinates)
CGContextTranslateCTM(context, 0, frame.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGContextClipToMask(context, frame, image.CGImage);
[tempView.layer renderInContext:context];
// Produce a new image from this context
CGImageRef imageRef = CGBitmapContextCreateImage(context);
UIImage *toReturn = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
UIGraphicsEndImageContext();
[tempView release];
return toReturn;
}
How about subclassing UIView and adding a UIImage ivar (called image)? Then you could override -drawRect: something like this, provided you had a boolean ivar called pressed that was set while touched.
- (void)drawRect:(CGRect)rect
{
[image drawAtPoint:(CGPointMake(0.0, 0.0))];
// if pressed, fill rect with dark translucent color
if (pressed)
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSaveGState(ctx);
CGContextSetRGBFillColor(ctx, 0.5, 0.5, 0.5, 0.5);
CGContextFillRect(ctx, rect);
CGContextRestoreGState(ctx);
}
}
You would want to experiment with RGBA values above. And, of course, non-rectangular shapes would require a bit more work - like a CGMutablePathRef.
UIImageView can have multiple images; you could have two versions of the image and switch to the darker one when needed.