I need to change the background color of the currently tabbed page in my UITabBarController. I've searched through every stackoverflow post I could find but nothing worked for me. I thought there would be something like UITabBar.Appearance.SelectedImageTintColor, just for the background color but it doesn't seem so.
For example, I want to change the color of that part when I am on the right tab:
Does someone know how to do that?
You could invoked the following code in your UITabBarController
public xxxTabBarController()
{
//...set ViewControllers
this.TabBar.BarTintColor = UIColor.Red;
}
Update
//3.0 here is if you have three child page in tab , set it as the current value in your project
//
var size = new CGSize(TabBar.Frame.Width / 3.0, IsFullScreen());
this.TabBar.SelectionIndicatorImage = ImageWithColor(size,UIColor.Green);
double IsFullScreen()
{
double height = 64;
if (UIDevice.CurrentDevice.CheckSystemVersion(11, 0))
{
if (UIApplication.SharedApplication.Delegate.GetWindow().SafeAreaInsets.Bottom > 0.0)
{
height = 84;
}
}
return height;
}
UIImage ImageWithColor(CGSize size, UIColor color)
{
var rect = new CGRect(0, 0, size.Width, size.Height);
UIGraphics.BeginImageContextWithOptions(size, false, 0);
CGContext context = UIGraphics.GetCurrentContext();
context.SetFillColor(color.CGColor);
context.FillRect(rect);
UIImage image = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
return image;
}
The trick is to use the SelectionIndicatorImage Property of the UITabBar and generate a completely filled image with your desired color using the following method:
private UIImage ImageWithColor(CGSize size)
{
CGRect rect = new CGRect(0, 0, size.Width, size.Height);
UIGraphics.BeginImageContext(size);
using (CGContext context = UIGraphics.GetCurrentContext())
{
context.SetFillColor(UIColor.Green); //change color if necessary
context.FillRect(rect);
}
UIImage image = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
return image;
}
To initialize everything we override ViewWillLayoutSubviews() like this:
public override void ViewWillLayoutSubviews()
{
base.ViewWillLayoutSubviews();
// The tabbar height will always be 49 unless we force it to reevaluate it's size on runtime ...
myTabBar.InvalidateIntrinsicContentSize();
double height = myTabBar.Frame.Height;
CGSize size = new CGSize(new nfloat(myTabBar.Frame.Width / myTabBar.Items.Length, height));
// Now get our all-green image...
UIImage image = ImageWithColor(size);
// And set it as the selection indicator
myTabBar.SelectionIndicatorImage = image;
}
As mentioned in this article (google translating it step by step when necessary lol) calling InvalidateIntrinsicContentSize() will force the UITabBar to reevaluate it's size and will get you the actual runtime height of the tab bar (instead of the constant 49 height value from XCode).
I'm working with google cardboard in unity.
In my main scene I have a skybox with an image as texture.
How can I get the color of the pixel I'm looking?
The skybox is an element of mainCamera, that is child of "Head".
I put also GvrReticle as child of head; is it useful for my purpose?
Thanks
Basically you wait for the end of the frame so that the camera has rendered. Then you read the rendered data into a texture and get the center pixel.
edit Be aware that if you have a UI element rendered in the center it will show the UI element color not the color behind.
private Texture2D tex;
public Color center;
void Awake()
{
StartCoroutine(GetCenterPixel());
}
private void CreateTexture()
{
tex = new Texture2D(1, 1, TextureFormat.RGB24, false);
}
private IEnumerator GetCenterPixel()
{
CreateTexture();
while (true)
{
yield return new WaitForEndOfFrame();
tex.ReadPixels(new Rect(Screen.width / 2f, Screen.height / 2f, 1, 1), 0, 0);
tex.Apply();
center = tex.GetPixel(0,0);
}
}
Is it possible to change the grey border-bottom color of the UINavigationBar in iOS7?
I already tried to remove to border, but this is not working:
[[UINavigationBar appearance] setShadowImage:[[UIImage alloc] init]];
Thanks!
You are removing the shadow but not the border, you need to do the following:
[[UINavigationBar appearance] setBackgroundImage:[[UIImage alloc] init] forBarMetrics:UIBarMetricsDefault];
[[UINavigationBar appearance] setShadowImage:[[UIImage alloc] init]];
To change the border use an image of 2 pixels width line:
[[UINavigationBar appearance] setShadowImage:[UIImage imageNamed:#"2pxWidthLineImage"]];
Here is a category to change bottom color with height:
[self.navigationController.navigationBar setBottomBorderColor:[UIColor redColor] height:1];
Objective C:
UINavigationBar+Helper.h
#import <UIKit/UIKit.h>
#interface UINavigationBar (Helper)
- (void)setBottomBorderColor:(UIColor *)color height:(CGFloat)height;
#end
UINavigationBar+Helper.m
#import "UINavigationBar+Helper.h"
#implementation UINavigationBar (Helper)
- (void)setBottomBorderColor:(UIColor *)color height:(CGFloat)height {
CGRect bottomBorderRect = CGRectMake(0, CGRectGetHeight(self.frame), CGRectGetWidth(self.frame), height);
UIView *bottomBorder = [[UIView alloc] initWithFrame:bottomBorderRect];
[bottomBorder setBackgroundColor:color];
[self addSubview:bottomBorder];
}
#end
Swift:
extension UINavigationBar {
func setBottomBorderColor(color: UIColor, height: CGFloat) {
let bottomBorderRect = CGRect(x: 0, y: frame.height, width: frame.width, height: height)
let bottomBorderView = UIView(frame: bottomBorderRect)
bottomBorderView.backgroundColor = color
addSubview(bottomBorderView)
}
}
Here is another way:
CALayer *border = [CALayer layer];
border.borderColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"border"]].CGColor;
border.borderWidth = 1;
CALayer *layer = self.navigationController.navigationBar.layer;
border.frame = CGRectMake(0, layer.bounds.size.height, layer.bounds.size.width, 1);
[layer addSublayer:border];
The only way I found to change color is:
override func viewDidLoad() {
super.viewDidLoad()
if let navigationController = self.navigationController {
let navigationBar = navigationController.navigationBar
let navigationSeparator = UIView(frame: CGRectMake(0, navigationBar.frame.size.height - 1, navigationBar.frame.size.width, 0.5))
navigationSeparator.backgroundColor = UIColor.redColor() // Here your custom color
navigationSeparator.opaque = true
self.navigationController?.navigationBar.addSubview(navigationSeparator)
}
}
I wrote an extension based on the other answers for easier usage in Swift:
extension UINavigationBar {
func setBottomBorderColor(color: UIColor) {
let navigationSeparator = UIView(frame: CGRectMake(0, self.frame.size.height - 0.5, self.frame.size.width, 0.5))
navigationSeparator.backgroundColor = color
navigationSeparator.opaque = true
navigationSeparator.tag = 123
if let oldView = self.viewWithTag(123) {
oldView.removeFromSuperview()
}
self.addSubview(navigationSeparator)
}
}
You can use this extension with calling the method in a context like that:
self.navigationController?.navigationBar.setBottomBorderColor(UIColor.whiteColor())
I found that pretty useful as I had to deal with that colored-border-problem.
I solved this problem with the use of autolayouts. The solution works on different screen sizes and with orientation change.
extension UINavigationBar {
#IBInspectable var bottomBorderColor: UIColor {
get {
return self.bottomBorderColor;
}
set {
let bottomBorderRect = CGRect.zero;
let bottomBorderView = UIView(frame: bottomBorderRect);
bottomBorderView.backgroundColor = newValue;
addSubview(bottomBorderView);
bottomBorderView.translatesAutoresizingMaskIntoConstraints = false;
self.addConstraint(NSLayoutConstraint(item: bottomBorderView, attribute: .trailing, relatedBy: .equal, toItem: self, attribute: .trailing, multiplier: 1, constant: 0));
self.addConstraint(NSLayoutConstraint(item: bottomBorderView, attribute: .leading, relatedBy: .equal, toItem: self, attribute: .leading, multiplier: 1, constant: 0));
self.addConstraint(NSLayoutConstraint(item: bottomBorderView, attribute: .top, relatedBy: .equal, toItem: self, attribute: .bottom, multiplier: 1, constant: 0));
self.addConstraint(NSLayoutConstraint(item: bottomBorderView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute,multiplier: 1, constant: 1));
}
}
}
Based on the answer from #sash I made an extension in Swift using Autolayout, explained right here.
In essence, the other solutions have the following pitfalls:
Cannot add dropshadow if using the UIImage solution
The subview added doesn't resize upon rotation of the view
extension UINavigationBar {
func setBottomBorderColor(color: UIColor, height: CGFloat) -> UIView {
let bottomBorderView = UIView(frame: CGRectZero)
bottomBorderView.translatesAutoresizingMaskIntoConstraints = false
bottomBorderView.backgroundColor = color
self.addSubview(bottomBorderView)
let views = ["border": bottomBorderView]
self.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[border]|", options: [], metrics: nil, views: views))
self.addConstraint(NSLayoutConstraint(item: bottomBorderView, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: height))
self.addConstraint(NSLayoutConstraint(item: bottomBorderView, attribute: .Bottom, relatedBy: .Equal, toItem: self, attribute: .Bottom, multiplier: 1.0, constant: height))
return bottomBorderView
}
}
This let you still add a drop shadow if you need to, and this handles rotation nicely !
If you like simple and hacky solutions like I do, create a view that covers the default border:
UIView *navBarLineView = [[UIView alloc] initWithFrame:CGRectMake(0, CGRectGetHeight(self.navigationController.navigationBar.frame),
CGRectGetWidth(self.navigationController.navigationBar.frame), 1)];
navBarLineView.backgroundColor = [UIColor redColor];
[self.navigationController.navigationBar addSubview:navBarLineView];
budidino solutions works very well. Here it is for Swift:
let navBarLineView = UIView(frame: CGRectMake(0,
CGRectGetHeight((navigationController?.navigationBar.frame)!),
CGRectGetWidth((self.navigationController?.navigationBar.frame)!),
1))
navBarLineView.backgroundColor = UIColor.whiteColor()
navigationController?.navigationBar.addSubview(navBarLineView)
Well, if you want to remove bottom border you set shadow image to empty image
[navigationBar setShadowImage:[UIImage new]];
so if you want to set it to another color just create image with that color, I use a helper function to create image from color below (original source http://jslim.net/blog/2014/05/05/ios-customize-uitabbar-appearance/)
+ (UIImage *)imageFromColor:(UIColor *)color forSize:(CGSize)size
{
return [UIImage imageFromColor:color forSize:size withCornerRadius:0];
}
+ (UIImage *)imageFromColor:(UIColor *)color forSize:(CGSize)size withCornerRadius:(CGFloat)radius
{
CGRect rect = CGRectMake(0, 0, size.width, size.height);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, rect);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Begin a new image that will be the new image with the rounded corners
// (here with the size of an UIImageView)
UIGraphicsBeginImageContext(size);
// Add a clip before drawing anything, in the shape of an rounded rect
[[UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:radius] addClip];
// Draw your image
[image drawInRect:rect];
// Get the image, here setting the UIImageView image
image = UIGraphicsGetImageFromCurrentImageContext();
// Lets forget about that we were drawing
UIGraphicsEndImageContext();
return image;
}
and in my navbar
[navigationBar setShadowImage:[UIImage imageFromColor:[UIColor redColor] forSize:CGSizeMake(CGRectGetWidth(self.tableView.frame), 1)]];
that's it, It's working for me, hope this help. Please consider changing the accepted answer because its not working and can be confusing
To build on #sash's Swift implementation you can make the border responsive to rotation/trait changes by using constraints:
extension UINavigationBar {
func setBottomBorderColor(color: UIColor, height: CGFloat) {
let bottomBorderView = UIView()
bottomBorderView.backgroundColor = color
bottomBorderView.translatesAutoresizingMaskIntoConstraints = false
addSubview(bottomBorderView)
// Add constraints to make the bar always stay at the bottom of the nav bar and change size with rotation/trait changes
let horizontalConstraint = NSLayoutConstraint(item: bottomBorderView, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerX, multiplier: 1, constant: 0)
let verticalConstraint = NSLayoutConstraint(item: bottomBorderView, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 0)
let widthConstraint = NSLayoutConstraint(item: bottomBorderView, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: .width, multiplier: 1, constant: 0)
let heightConstraint = NSLayoutConstraint(item: bottomBorderView, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: height)
self.addConstraints([horizontalConstraint, verticalConstraint, widthConstraint, heightConstraint])
}
}
Here's the method for creating image with clear color:
+ (UIImage*)imageFromColor:(UIColor *)color withSize:(CGSize)sizeImage
{
UIImage *resultImage = nil;
UIGraphicsBeginImageContext(sizeImage);
CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(), color.CGColor);
CGContextFillRect(UIGraphicsGetCurrentContext(), CGRectMake(0.0f, 0.0f, sizeImage.width, sizeImage.height));
resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resultImage;
}
Here's it's usage for removing annoying bottom line:
navigationBar.shadowImage = [UIImage imageFromColor:[UIColor clearColor] withSize:CGSizeMake(1.0f, 1.0f)];
Picture 1
you can use Reveal to see the border color is the UIImageView's backgroundColor.
so directly modifying the imageView's backgroundColor or hide it.
the code: i write in #interface QdtTabBarController : UITabBarController
Class backGroundClass = NSClassFromString(#"_UIBarBackground");
for (UIView *view in self.tabBar.subviews) {
if ([view isKindOfClass:backGroundClass]) {
for (UIView *view2 in view.subviews) {
if ([view2 isKindOfClass:[UIImageView class]]) {
dispatch_async(dispatch_get_main_queue(), ^{
view2.backgroundColor = [UIColor redColor];
});
};
};
break;
}
}
Picture 2
I'm using RubyMotion with the RedPotion gem, which includes a StandardAppearance class. This is what I did!
Put this line at the top of your app_delegate.rb, just before the on_load method:
ApplicationStylesheet.new(nil).application_setup
Then, in your application_stylesheet.rb, put this as the last line in the application_setup method:
StandardAppearance.apply app.window
And then this is my StandardAppearance class:
class StandardAppearance
def self.apply(window)
Dispatch.once do
UINavigationBar.appearance.tap do |o|
o.setBackgroundImage(UIImage.alloc.init, forBarMetrics: UIBarMetricsDefault)
o.shadowImage = UIImage.alloc.init
end
end
end
end
This will help you :)
[self.navigationController.navigationBar.layer setBorderWidth:2.0];// Just to make sure its working
[self.navigationController.navigationBar.layer setBorderColor:[[UIColor redColor] CGColor]];
I would like to draw a string on the screen, rotated by 90 degrees, on a transparent background:
public static void drawStringWithTransformROT90(String text, int x, int y, int color, Graphics g) {
// create a mutable image with white background color
Image im = Image.createImage(g.getFont().stringWidth(text), g.getFont().getHeight());
Graphics imGraphics = im.getGraphics();
// set text color to black
imGraphics.setColor(0x00000000);
imGraphics.drawString(text, 0, 0, Graphics.TOP|Graphics.LEFT);
int[] rgbData = new int[im.getWidth() * im.getHeight()];
im.getRGB(rgbData, 0, im.getWidth(), 0, 0, im.getWidth(), im.getHeight());
for (int i = 0; i < rgbData.length; i++) {
// if it is the background color (white), set it to transparent
if (rgbData[i] == 0xffffffff) {
rgbData[i] = 0x00000000;
} else {
// otherwise (black), change the text color
rgbData[i] = color;
}
}
Image imageWithAlpha = Image.createRGBImage(rgbData, im.getWidth(), im.getHeight(), true);
Sprite s = new Sprite(imageWithAlpha);
// rotate the text
s.setTransform(Sprite.TRANS_ROT90);
s.setPosition(x, y);
s.paint(g);
}
Is there any better way to do this? Should I create a transparent image with the alphabet rotated, and draw it using a Sprite object?
import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.Sprite;
public class MyCanvas extends Canvas {
public void paint(Graphics g) {
//The text that will be displayed
String s="java";
//Create the blank image, specifying its size
Image img=Image.createImage(50,50);
//Create an instance of the image's Graphics class and draw the string to it
Graphics gr=img.getGraphics();
gr.drawString(s, 0, 0, Graphics.TOP|Graphics.LEFT);
//Display the image, specifying the rotation value. For example, 90 degrees
g.drawRegion(img, 0, 0, 50, 50, Sprite.TRANS_ROT90, 0, 0, Graphics.TOP|Graphics.LEFT);
}
}
As found at http://wiki.forum.nokia.com/index.php/How_to_display_rotated_text_in_Java_ME
If you use Java2D for drawing you can specify java.awt.Graphics2D#setTransform.