如何在 Xamarin.Forms 中获取/检测屏幕尺寸? [英] How to get/detect screen size in Xamarin.Forms?

问题描述

我正在尝试重写我为 iOS 编写的应用程序.我打算写一个 android 版本，但认为最好让这个有机会使用 Xamarin.Forms.一次做一页，现在我被困在需要获取屏幕宽度和高度的页面上.有谁知道 Xamarin.Forms 中 iOS 的 View.Frame.Width 等价物?

I am trying to rewrite an app that I wrote for iOS. I was going to write an android version but thought It'd be better to make this the opportunity to use Xamarin.Forms. Doing it one page at a time, now I'm stuck on a page where I need to get the screen's width and height. Does anyone know the equivalent of iOS' View.Frame.Width in Xamarin.Forms?

推荐答案

目前没有来自 Xamarin.Forms 本身的方法，但我们在 Xamarin.Forms.Labs 中将其实现为 PCL 兼容接口，您可以从 NuGet 获得或来自 GitHub 的源代码.

There isn't currently a way from Xamarin.Forms itself but we have it implemented as PCL compatible interface in Xamarin.Forms.Labs which you can get from NuGet or source code from GitHub.

https://github.com/XForms/Xamarin-Forms-Labs

IDevice 具有包含信息的 IDisplay 属性；X & 的高度、宽度、像素密度Y 和几种以英寸为单位计算尺寸的扩展方法.

IDevice has IDisplay property with the information; height, width, pixel density for X & Y and couple of extension methods to calculate sized in inches.

从设备获取信息的示例页面:

Sample page for getting information from the device:

https://github.com/XForms/Xamarin-Forms-Labs/blob/master/samples/Xamarin.Forms.Labs.Sample/Pages/Services/ExtendedDeviceInfoPage.cs

        #region Display information
        var display = device.Display;
        var displayFrame = new Frame();
        if (display != null)
        {
            displayFrame.Content = new StackLayout()
            {
                Children =
                {
                    new Label() { Text = display.ToString() },
                    new Label() { Text = string.Format("Screen width is	 {0:0.0} inches.", display.ScreenWidthInches()) },
                    new Label() { Text = string.Format("Screen height is	 {0:0.0} inches.", display.ScreenHeightInches()) },
                    new Label() { Text = string.Format("Screen diagonal size is	 {0:0.0} inches.", display.ScreenSizeInches()) }
                            }
                        };
        }
        else
        {
            displayFrame.Content = new Label() { TextColor = Color.Red, Text = "Device does not contain display information." };
        }

        stack.Children.Add(displayFrame); 
        #endregion

无论显示属性如何，都可以在所有平台上创建精确的一英寸一英寸的框架:

Creating an exact inch-by-inch frame on all platforms regardless of display properties:

https://github.com/XForms/Xamarin-Forms-Labs/blob/master/samples/Xamarin.Forms.Labs.Sample/Pages/Services/AbsoluteLayoutWithDisplayInfoPage.cs

public class AbsoluteLayoutWithDisplayInfoPage : ContentPage
{
    public AbsoluteLayoutWithDisplayInfoPage(IDisplay display)
    {
        this.Title = "Absolute Layout With Display Info";
        var abs = new AbsoluteLayout();
        var inchX = display.WidthRequestInInches(1);
        var inchY = display.HeightRequestInInches(1);
        var originX = display.WidthRequestInInches(display.ScreenWidthInches() / 2);
        var originY = display.HeightRequestInInches(display.ScreenHeightInches() / 2);

        abs.Children.Add(new Label() { Text = "1"x"1" blue frame" });

        abs.Children.Add(new Frame()
            {
                BackgroundColor = Color.Navy,
            },
            new Rectangle(originX - inchX/2, originY - inchY/2, inchX, inchY));

        abs.Children.Add(new Frame()
            {
                BackgroundColor = Color.White
            },
            new Rectangle(originX - inchX/16, originY - inchY/16, inchX/8, inchY/8));

        this.Content = abs;
    }
}

要获取设备信息，请设置您的 DI 解析器或使用静态容器.所有 3 个平台都有一个带有静态 CurrentDevice 属性的单例设备调用:

To get to the device info either set your DI resolver or use a static container. All 3 platforms have a singleton device calls with static CurrentDevice property:

resolverContainer.Register<IDevice>(t => WindowsPhoneDevice.CurrentDevice)
resolverContainer.Register<IDevice>(t => AppleDevice.CurrentDevice)
resolverContainer.Register<IDevice>(t => AndroidDevice.CurrentDevice)

这篇关于如何在 Xamarin.Forms 中获取/检测屏幕尺寸?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！