So im trying to implement a svg gradiant background image but when i set the svg image it only displays the solid colour(gradient just doesnt display).
This is the code im using and ive tested it on regular svg images and works fine but doesnt work whenever I add a gradient svg file.
public App()
{
// The root page of your application
MainPage = new ContentPage
{
Content = new StackLayout
{
BackgroundColor = Color.White,
VerticalOptions = LayoutOptions.FillAndExpand,
Children =
{
new SvgImage
{
SvgPath = "SVG_Test.Images.drawing.svg",
SvgAssembly = typeof(App).GetTypeInfo().Assembly,
HeightRequest = 1000,
WidthRequest = 500
}
}
}
};
}
Could anyone point me in the right direction?
Related
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 needed to create a UICollectionView containing the profiles of users searched in my database.
The UICollectionView must contain a UILabel and a UIImage, the name and image must be taken from PHP. I currently get both, but when I go to do a new search, the old information overlaps the new, creating a confusing effect like this:
I am developing on xamarin.ios, I am attaching the portion of code that deals with the visual output of the UILabel and UIImage elements.
public void UpdateCell(string elemento)
{
img = new UIImageView(UIImage.FromBundle("ProfiloImgNotFound"));
UILabel name = new UILabel { Text = elemento, TextColor = UIColor.SecondaryLabelColor, TextAlignment = UITextAlignment.Center };
Console.WriteLine(name.Text);
name.Font = UIFont.FromName(".AppleSystemUIFont", 20);
var labelHeight = 20;
var labelWidth = img.Bounds.Width;
name.Frame = new CGRect(0, img.Bounds.Height + 10, labelWidth, labelHeight);
AddSubviews(new UIView[] { img, name });
}
I tried to add the svg image which contains opacity=0 area into QTextureMaterial on QPlaneMesh, but it shows that the Plane's background is always in gray.
I want that the plane can cantain my image and penetrate to other object in opacity=0 area.
The svg file like https://image.flaticon.com/icons/svg/3154/3154348.svg .
code:
// Background
Qt3DCore::QEntity *planeEntity = new Qt3DCore::QEntity(rootEntity);
Qt3DExtras::QPlaneMesh *planeMesh = new Qt3DExtras::QPlaneMesh(planeEntity);
planeMesh->setHeight(2);
planeMesh->setWidth(2);
Qt3DExtras::QTextureMaterial *planeMaterial = new Qt3DExtras::QTextureMaterial(planeEntity);
Qt3DRender::QTexture2D *planeTexture = new Qt3DRender::QTexture2D(planeMaterial);
FlippedTextureImage *planeTextureImage = new FlippedTextureImage(planeTexture);
planeTextureImage->setSize(QSize(3507, 3000));
planeTexture->addTextureImage(planeTextureImage);
planeMaterial->setTexture(planeTexture);
Qt3DCore::QTransform *planeTransform = new Qt3DCore::QTransform(planeEntity);
planeTransform->setRotationX(90);
planeTransform->setTranslation(QVector3D(0, 0, 0));
Qt3DExtras::QPhongAlphaMaterial *pam2 = new Qt3DExtras::QPhongAlphaMaterial(planeEntity);
pam2->setAlpha(0);
planeEntity->addComponent(planeMesh);
planeEntity->addComponent(pam2);
planeEntity->addComponent(planeMaterial);
planeEntity->addComponent(planeTransform);
class FlippedTextureImage : public Qt3DRender::QPaintedTextureImage
{
public:
FlippedTextureImage(Qt3DCore::QNode *parent = Q_NULLPTR):Qt3DRender::QPaintedTextureImage(parent) {}
void paint(QPainter *painter) override {
QSvgRenderer renderer(QString(qApp->applicationDirPath() + "/gift.svg"));
QImage image(3000, 3000, QImage::Format_RGBA64); // 512x512 RGBA
image.fill(0x00ffffff); // white background
QPainter painter2(&image);
renderer.render(&painter2);
painter->drawImage(0, 0, image);
}
};
and run code like this
QTextureMaterial doesn't support transparency in the textures.
Check out my answer to this question to see how to implement transparency in textures yourself. There is not out-of-the-box solution in Qt3D.
The solution for centering any subview within a parent is usually simple, however, it doesn't seem to work in my case.
I'm working with a UICollectionView and have added a Header class programmatically. I have this constructor, where I also try to center the label within the screen:
[Export("initWithFrame:")]
public Header(System.Drawing.RectangleF frame) : base(frame)
{
label = new UILabel
{
Frame = new System.Drawing.RectangleF(frame.Size.Width / 2, 50, 200, 50),
BackgroundColor = UIColor.Clear,
TextColor = UIColor.White,
Font = UIFont.FromName("HelveticaNeueLTStd-ThCn", 35f),
Text = DateTime.Now.ToString("Y")
};
AddSubview(label);
}
And I initialize the class inside the UICollectionViewSource 's constructor like this:
public MyCollectionViewDataSource(MainController mainController, DateTime currentDate)
{
try
{
controller = mainController;
new Header(new RectangleF(0, 0, (float)mainController.View.Frame.Size.Width, 200));
}
catch (Exception ex)
{
Console.WriteLine(ex.Message + ex.StackTrace);
}
}
What exactly am I missing because this usually works in other instances but seems to fail here?
This is what it looks like :
I found an explanation here iOS Layout Gotchas by Adam Kemp which helped me resolve this issue.
The first solution
One very common mistake I made was adding the layout definition code in the constructor, instead of doing it in the rightful place : the LayoutSubviews override in this case.
Giving the label the frame size in the constructor assumes a static size set at the time of construction, which may later change depending on the screen size.
The second solution
He explains that :
Frame sets the position of a view within its parent while Bounds is in the coordinate system of the view itself (not its parent).
So, to center the UILabel, I used bounds and center together and this worked for me.
[Export("initWithFrame:")]
public Header(CGRect bounds) : base(bounds)
{
label = new UILabel
{
BackgroundColor = UIColor.Clear,
TextColor = UIColor.White,
Font = UIFont.FromName("HelveticaNeueLTStd-ThCn", 35f),
Text = DateTime.Now.ToString("Y"),
TextAlignment = UITextAlignment.Center
};
rectangle = bounds;
AddSubview(label);
}
public override void LayoutSubviews()
{
base.LayoutSubviews();
label.Bounds = new CGRect (rectangle.Size.Width / 2, 50, 200, 50);
label.Center = new PointF((float)rectangle.Size.Width/2,50);
}
My iOS 6 code to show the camera in a UIPopoverController works fine but iOS won't scale the camera view. Please see images below. Any suggestions would be appreciated.
Edit
public class NoRotationUIImagePickerController : UIImagePickerController
{
public override bool ShouldAutorotate ()
{
return false;
}
}
//place imagePicker into a container so that we can control the size of the popover
container = new UIViewController();
container.ContentSizeForViewInPopover = new SizeF(parentViewController.View.Frame.Width, parentViewController.View.Frame.Height);
container.View.AddSubview(_imagePicker.View);
_popOver = new UIPopoverController (container);
//If no camera is available, return false and do nothing.
if (IsCameraHardwareAvailable())
{
_imagePicker.Delegate = new PopUpGalleryPickerDelegate (_popOver, _imageSelected);
_imagePicker.SourceType = UIImagePickerControllerSourceType.Camera;
_imagePicker.AllowsEditing = false;
_imagePicker.MediaTypes = new string[] {"public.image"};
RectangleF popRectangle = new RectangleF (new PointF(parentViewController.View.Frame.Width/2, parentViewController.View.Frame.Height/2), new SizeF (1, 1));
_popOver.PresentFromRect(popRectangle, parentViewController.View, 0, true);
_imagePicker.View.Frame = container.View.Frame; //change to frame must come after popover is presented.
}
else
{
cameraAvailable = false;
}
The solution I ended up with was to make the camera full screen instead of using a popover controller.