Xamarin.Forms中的主从页面的主页面有多宽? [英] How wide is the master page of a Master-Detail Page in Xamarin.Forms?
问题描述
取决于屏幕尺寸(和设备惯用语?)，母版页的宽度会有所不同:在手机上，其约为屏幕宽度的80％，而在平板电脑上，它的尺寸似乎是恒定的，如320 dp. /p>
有人知道这个值的一般公式吗?我想用它在尚未设置Width属性的情况下，在构造期间布置一些元素.
修改: 我知道如何获取当前屏幕尺寸.但是，所显示的Xamarin.Form母版详细页的宽度与它的宽度有何关系?它不会覆盖整个屏幕，但会根据设备而填充整个屏幕的不同部分.
您可以请求设备的实际屏幕宽度，高度和比例因子.
(来自 https://github.com/mattregul/Xamarin_GetDeviceScreensize )
iOS AppDelegate.cs
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
global::Xamarin.Forms.Forms.Init();
// Store off the device sizes, so we can access them within Xamarin Forms
App.DisplayScreenWidth = (double)UIScreen.MainScreen.Bounds.Width;
App.DisplayScreenHeight = (double)UIScreen.MainScreen.Bounds.Height;
App.DisplayScaleFactor = (double)UIScreen.MainScreen.Scale;
LoadApplication(new App());
return base.FinishedLaunching(app, options);
}
}
Android MainActivity.cs
[Activity(Label = "Xamarin_GetDeviceScreensize.Droid", Icon = "@drawable/icon", Theme = "@style/MyTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
// Store off the device sizes, so we can access them within Xamarin Forms
App.DisplayScreenWidth = (double)Resources.DisplayMetrics.WidthPixels / (double)Resources.DisplayMetrics.Density; // Width = WidthPixels / Density
App.DisplayScreenHeight = (double)Resources.DisplayMetrics.HeightPixels / (double)Resources.DisplayMetrics.Density; // Height = HeightPixels / Density
App.DisplayScaleFactor = (double)Resources.DisplayMetrics.Density;
global::Xamarin.Forms.Forms.Init(this, bundle);
LoadApplication(new App());
}
}
Xamarin Forms App.cs
public class App : Application
{
public static double DisplayScreenWidth;
public static double DisplayScreenHeight;
public static double DisplayScaleFactor;
public App()
{
string ScreenDetails = Device.OS.ToString() + " Device Screen Size:\n" +
$"Width: {DisplayScreenWidth}\n" +
$"Height: {DisplayScreenHeight}\n" +
$"Scale Factor: {DisplayScaleFactor}";
// The root page of your application
var content = new ContentPage
{
Title = "Xamarin_GetDeviceScreensize",
Content = new StackLayout
{
VerticalOptions = LayoutOptions.Center,
Children = {
new Label {
HorizontalTextAlignment = TextAlignment.Center,
FontSize = Device.GetNamedSize (NamedSize.Large, typeof(Label)),
Text = ScreenDetails
}
}
}
};
MainPage = new NavigationPage(content);
}
}
Depending on the screen size (and device idiom?) the width of the master page varies: On phones it is about 80 % of the screen width, while on tablets it seems to be a constant dimension like 320 dp.
Does anybody know a general formula for this value? I'd like to use it for laying out some elements during construction time, when the Width property isn't set, yet.
Edit: I know how to get the current screen size. But how does the width of the presented master page of Xamarin.Form's master-detail page relate to it? It doesn't cover the whole screen, but fills a different fraction of it depending on the device.
You could request the device's actual screen width, height, and scale factor.
(From https://github.com/mattregul/Xamarin_GetDeviceScreensize)
iOS AppDelegate.cs
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
global::Xamarin.Forms.Forms.Init();
// Store off the device sizes, so we can access them within Xamarin Forms
App.DisplayScreenWidth = (double)UIScreen.MainScreen.Bounds.Width;
App.DisplayScreenHeight = (double)UIScreen.MainScreen.Bounds.Height;
App.DisplayScaleFactor = (double)UIScreen.MainScreen.Scale;
LoadApplication(new App());
return base.FinishedLaunching(app, options);
}
}
Android MainActivity.cs
[Activity(Label = "Xamarin_GetDeviceScreensize.Droid", Icon = "@drawable/icon", Theme = "@style/MyTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
// Store off the device sizes, so we can access them within Xamarin Forms
App.DisplayScreenWidth = (double)Resources.DisplayMetrics.WidthPixels / (double)Resources.DisplayMetrics.Density; // Width = WidthPixels / Density
App.DisplayScreenHeight = (double)Resources.DisplayMetrics.HeightPixels / (double)Resources.DisplayMetrics.Density; // Height = HeightPixels / Density
App.DisplayScaleFactor = (double)Resources.DisplayMetrics.Density;
global::Xamarin.Forms.Forms.Init(this, bundle);
LoadApplication(new App());
}
}
Xamarin Forms App.cs
public class App : Application
{
public static double DisplayScreenWidth;
public static double DisplayScreenHeight;
public static double DisplayScaleFactor;
public App()
{
string ScreenDetails = Device.OS.ToString() + " Device Screen Size:\n" +
$"Width: {DisplayScreenWidth}\n" +
$"Height: {DisplayScreenHeight}\n" +
$"Scale Factor: {DisplayScaleFactor}";
// The root page of your application
var content = new ContentPage
{
Title = "Xamarin_GetDeviceScreensize",
Content = new StackLayout
{
VerticalOptions = LayoutOptions.Center,
Children = {
new Label {
HorizontalTextAlignment = TextAlignment.Center,
FontSize = Device.GetNamedSize (NamedSize.Large, typeof(Label)),
Text = ScreenDetails
}
}
}
};
MainPage = new NavigationPage(content);
}
}
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