I have been developing a Xamarin forms application. I want to increase the height of the progress bar control. I used custom renders to change the color of the progress control. But I couldn't find any way to increase the height. Please help me. following is my Custom render class.
public class MyProgressBarRenderer:ProgressBarRenderer
{
protected override void OnElementChanged (
ElementChangedEventArgs<Xamarin.Forms.ProgressBar> e)
{
base.OnElementChanged (e);
Control.ProgressTintColor = Color.FromHex ("#254f5e").ToUIColor();
}
}
Add this override to MyProgressBarRenderer, and adjust Y as necessary....
using UIKit;
using CoreGraphics;
......
public override void LayoutSubviews()
{
base.LayoutSubviews();
var X = 1.0f;
var Y = 5.0f;
CGAffineTransform transform = CGAffineTransform.MakeScale(X,Y);
this.Transform = transform;
}
There is small issue in the iOS renderer code try using
this.Control.Transform = transform;
instead of
this.Transform = transform;
Related
I'm developing in Xamarin and I don't know how change the height of navigation bar.
For android is easier because you've got a clear property "ActionBarSize"
I've tried a lot of things. Create a comun NavigationPage with HeightRequest property does not work
Thanks a lot
In iOS we could set a custom TitlView by using custom renderer .
using Foundation;
using UIKit;
using Xamarin.Forms.Platform.iOS;
using Xamarin.Forms;
using xxx.iOS;
using CoreGraphics;
using xxx;
using ObjCRuntime;
[assembly: ExportRenderer(typeof(ContentPage), typeof(MyPageRenderer))]
namespace xxx.iOS
{
public class MyPageRenderer: PageRenderer
{
public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
var page = Element as ContentPage;
NavigationController.NavigationBar.Hidden = true;
double height = IsiphoneX();
UIView backView = new UIView()
{
BackgroundColor = UIColor.White,
Frame = new CGRect(0,20,UIScreen.MainScreen.Bounds.Width, height),
};
UIButton backBtn = new UIButton() {
Frame = new CGRect(20, height-44, 40, 44),
Font = UIFont.SystemFontOfSize(18),
} ;
backBtn.SetTitle("Back", UIControlState.Normal);
backBtn.SetTitleColor(UIColor.Blue, UIControlState.Normal);
backBtn.AddTarget(this,new Selector("GoBack"),UIControlEvent.TouchUpInside);
UILabel titleLabel = new UILabel() {
Frame=new CGRect(UIScreen.MainScreen.Bounds.Width/2-75, 0,150, height),
Font = UIFont.SystemFontOfSize(20),
Text = page.Title,
TextColor = UIColor.Black,
Lines = 0,
};
UILabel line = new UILabel() {
Frame = new CGRect(0, height, UIScreen.MainScreen.Bounds.Width, 0.5),
BackgroundColor = UIColor.Black,
};
backView.AddSubview(backBtn);
backView.AddSubview(titleLabel);
backView.AddSubview(line);
View.AddSubview(backView);
}
double IsiphoneX()
{
double height = 44; //set height as you want here !!!
if (UIDevice.CurrentDevice.CheckSystemVersion(11, 0))
{
if (UIApplication.SharedApplication.Delegate.GetWindow().SafeAreaInsets.Bottom > 0.0)
{
height = 64; //set height as you want here !!!
}
}
return height;
}
[Export("GoBack")]
void GoBack()
{
NavigationController.PopViewController(true);
}
public override void ViewWillDisappear(bool animated)
{
base.ViewWillDisappear(animated);
NavigationController.NavigationBar.Hidden = false;
}
}
}
I have a page renderer for camera and I want to put bottom menu on this renderer page in native not Xamarin.Forms page. How can I achieve this?
Adjust the Frame of View and NavigationBar in PageRenderer.
Create Custom Renderer for Page named CustomPageRender.
[assembly: ExportRenderer(typeof(Page), typeof(CustomPageRender))]
namespace FormsApp2.iOS
{
class CustomPageRender :PageRenderer
{
public override void ViewWillLayoutSubviews()
{
base.ViewWillLayoutSubviews();
if (this.NavigationController != null)
{
CGRect rect = View.Frame;
rect.Y = -44;
View.Frame = rect;
CGRect NavRect = NavigationController.NavigationBar.Frame;
NavRect.Y = UIScreen.MainScreen.Bounds.Height - 44;
NavigationController.NavigationBar.Frame = NavRect;
}
}
}
}
I am trying to change the height of a progress bar by using a custom renderer like here
The problem is, when the screen is rotated, the progress bar goes back to normal. Can someone help me?
I am using the same solution:
public override void LayoutSubviews()
{
base.LayoutSubviews();
var X = 1.0f;
var Y = 10.0f;
CGAffineTransform transform = CGAffineTransform.MakeScale(X, Y);
this.Control.Transform = transform;
}
I thnk you need to call the command SetNeedsLayout as discussed here . Of course you can also disable orientation change.
public override void OnConfigurationChanged (Android.Content.Res.Configuration newConfig)
{
base.OnConfigurationChanged (newConfig);
SetNeedsLayout ();
}
I have the following CustomRenderer to apply a style to buttons in my iOS project of my cross-platform Xamarin.Forms app.
The button used to have rounded edges, white text, and a blue gradient background.
Everything has been working just fine up until I downloaded Xcode 8.1. Since moving to 8.1, the same code will not present the background gradient. Can anyone see how I could change my code to get the background gradient working again?
The border radius and text color are all working as usual - it's just the background gradient which is missing.
[assembly: ExportRenderer(typeof(CustomButton), typeof(CustomButtonRenderer))]
namespace MyApp.Forms.iOS.CustomRenderers
{
class CustomButtonRenderer : ButtonRenderer
{
public override void LayoutSubviews()
{
foreach (var layer in Control?.Layer.Sublayers.Where(layer => layer is CAGradientLayer))
{
layer.Frame = Control.Bounds;
}
base.LayoutSubviews();
}
protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
{
base.OnElementChanged(e);
if (e.OldElement == null)
{
var gradient = new CAGradientLayer();
gradient.CornerRadius = Control.Layer.CornerRadius = 10;
gradient.Colors = new CGColor[]
{
UIColor.FromRGB(153, 204, 255).CGColor,
UIColor.FromRGB(51, 102, 204).CGColor
};
var layer = Control?.Layer.Sublayers.LastOrDefault();
Control?.Layer.InsertSublayerBelow(gradient, layer);
Control.SetTitleColor(UIColor.White, UIControlState.Normal);
Control.Layer.BorderColor = UIColor.FromRGB(51, 102, 204).CGColor;
Control.Layer.BorderWidth = 1;
}
}
}
}
Ok so I have finally worked out what was going on. In the LayoutSubviews method where I was setting each layer.Frame to the value of Control.Bounds, I noticed that Control.Bounds was a rectangle full of zeros, so my gradient was therefore 0 pixels in size.
I have modified the method as follows and it now works as expected again:
public override void LayoutSubviews()
{
var newBounds = Element.Bounds.ToRectangleF();
foreach (var layer in Control?.Layer.Sublayers.Where(layer => layer is CAGradientLayer))
{
layer.Frame = new CGRect(0, 0, newBounds.Width, newBounds.Height);
}
base.LayoutSubviews();
}
I'm not sure if this is a hack, but it seems to do the job - for now...
I am creating one Xamarin Forms project and I got stuck in finding the current screen width according to the different device.
I know how it can be done in android and ios but need a way to find the width in portable.
You can try this Application.Current.MainPage.Width in my case this worked and i am able to find the device width in portable project itself.
I know it is an old thread but worth mentioning that recently Xamarin.Essentials NuGet pakage was released and there is a useful class DeviceDisplay in there that should handle this task for you.
The documentation can be found here.
Usage example:
// Get Metrics
var mainDisplayInfo = DeviceDisplay.MainDisplayInfo;
// Orientation (Landscape, Portrait, Square, Unknown)
var orientation = mainDisplayInfo.Orientation;
// Rotation (0, 90, 180, 270)
var rotation = mainDisplayInfo.Rotation;
// Width (in pixels)
var width = mainDisplayInfo.Width;
// Width (in xamarin.forms units)
var xamarinWidth = width / mainDisplayInfo.Density;
// Height (in pixels)
var height = mainDisplayInfo.Height;
// Screen density
var density = mainDisplayInfo.Density;
Common code (in App.xaml.cs)
public static int ScreenHeight {get; set;}
public static int ScreenWidth {get; set;}
Android part (in MainActivity.cs, in the OnCreate method)
App.ScreenHeight = (int) (Resources.DisplayMetrics.HeightPixels / Resources.DisplayMetrics.Density);
App.ScreenWidth = (int) (Resources.DisplayMetrics.WidthPixels / Resources.DisplayMetrics.Density);
iOS part (in AppDelegate.cs, in the FinishedLaunching method)
App.ScreenHeight = (int)UIScreen.MainScreen.Bounds.Height;
App.ScreenWidth = (int)UIScreen.MainScreen.Bounds.Width;
So App.ScreenHeight and App.ScreenWidth will be initialized when the App will be launched, then you will be able to use them anywhere in the common code.
You can use the Width property when you are in a ContentPage. For example,
protected override void OnAppearing()
{
base.OnAppearing();
double w = this.Width;
}
Note that this is set during the Layout phase. So, you can only use it after the page is initialized, otherwise it is -1.
https://developer.xamarin.com/api/property/Xamarin.Forms.VisualElement.Width/
I would like to create a static struct in the shared code, so I can access the screen width/height values easily (as well as doing bindings in xAML).
The struct in the app namespace (e.g. in App.xaml.cs):
using System;
using Xamarin.Forms;
namespace YourAppName {
...
public struct Constant {
public static double ScreenWidth = Application.Current.MainPage.Width;
public static double ScreenHeight = Application.Current.MainPage.Height;
}
}
Retrieving screen width in C#:
var labelWidth = Constant.ScreenHeight * 0.2;
// then do something with labelWidth
Retrieving screen width in XAML:
<Label Text="Text with insane font size" FontSize="{Binding Source={x:Static local:Constant.ScreenWidth}}"/>
Another approach would be to use the override "OnSizeAllocated" for your page and then take the height and width according to the changes on the user's screen. You can create a static class to set the height and width of your screen everytime it changes and then access them from this class when needed.
The static class to set and access the device dimension:
public static class ScreenDimensions
{
public static double Height { get; set; }
public static double Width { get; set; }
}
Override to obtain the screen dimensions:
protected override void OnSizeAllocated(double width, double height)
{
base.OnSizeAllocated(width, height);
ScreenDimensions.Height = height;
ScreenDimensions.Width = width;
}
I Guess that the best way is use the xamarin.forms.Device information.
Size size = Device.Info.PixelScreenSize;
if (size.Width <= 720 && size.Height <= 1280)
{
stkLayoutTop.Margin = new Thickness(5, 30, 10, 0);
}
else
{
stkLayoutTop.Margin = new Thickness(5, 50, 10, 0);
}