endregion

Question

如何在共享代码中访问Xamarin.Android设备的屏幕宽度和高度？我无法使用资源。它在给定的上下文中找不到资源。

要清楚，我想为不同的方向（肖像和风景）展示不同的设计。因此，我希望在共享代码中达到平板电脑/手机的方向。

这是我的第一个问题，询问是否有办法检查它是横向还是纵向： A way to check if it is in the landscape or portrait mode in Xamarin.Android

我认为共享代码中Android手机的屏幕宽度和高度对我有帮助。

Answer 1

onConfigurationChanged可帮助您检测设备是横向还是纵向。关注this

如果你真的想获得屏幕宽度或高度。试试这个

/**
 * @param activity Context
 * @return a integer value represent the width of physical device
 */
public static int getScreenHeight(Activity activity) {
    DisplayMetrics metrics = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
    return metrics.heightPixels;
}

/**
 * @param activity Context
 * @return a integer value represent the width of physical device
 */
public static int getScreenWidth(Activity activity) {
    DisplayMetrics metrics = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
    return metrics.widthPixels;
}

Answer 2

实际上，在xamarin developer guide website上可以找到xamarin.android中检测屏幕大小的优秀指南。

在＆＃39; Activity.cs＆＃39;在onCreat方法中只需添加以下内容：

public static Rotation screenOrientation;

protected override void OnCreate(Bundle bundle)
{
    base.OnCreate(bundle);
    SetContentView(Resource.Layout.Main);

    var metrics = Resources.DisplayMetrics;
    var widthInDp = ConvertPixelsToDp(metrics.WidthPixels);
    var heightInDp = ConvertPixelsToDp(metrics.HeightPixels);

    if(widthInDp > heightInDp)
    {
        screenOrientation = Rotation.Landscape;
    }
    else
    {
        screenOrientation = Rotation.Portrait;
    }
}

如果你想轻易区分风景和肖像，我会在某个地方使用一点枚举。

public enum Rotation
{
    Landscape,
    Portrait
}

我认为这样的事情可以解决问题。

Answer 3

以下代码将有助于根据移动屏幕的高度和宽度设计移动屏幕。

基于此的设计将适合所有移动分辨率。

<强> PCL：

<强> App.cs

public class App : Application
{                     
  public static int screenHeight, screenWidth;

 public App()
  {           
    MainPage = new UserLogin();
    //The root page of your application         
   }

   protected override void OnStart()
   {
     // Handle when your app starts
   }

protected override void OnSleep()
{
    // Handle when your app sleeps
}

protected override void OnResume()
{
    // Handle when your app resumes
   }
 }

<强> Xamarin.Android：

<强> MainActivity.cs

#region用于屏幕高度＆amp;宽度

    var pixels = Resources.DisplayMetrics.WidthPixels;
    var scale = Resources.DisplayMetrics.Density;

    var dps = (double)((pixels - 0.5f) / scale);

    var ScreenWidth = (int)dps;

    App.screenWidth = ScreenWidth;

    //RequestedOrientation = ScreenOrientation.Portrait;

    pixels = Resources.DisplayMetrics.HeightPixels;
    dps = (double)((pixels - 0.5f) / scale);

    var ScreenHeight = (int)dps;
    App.screenHeight = ScreenHeight;

endregion

<强> Xamarin.iOS

<强> AppDelegate.cs

#region For Screen Height & Width

  App.screenWidth = (int)UIScreen.MainScreen.Bounds.Width;
      App.screenHeight = (int)UIScreen.MainScreen.Bounds.Height;

#endregion

<强> PCL：

如果您使用MVVM模式，则必须在ViewModel中获取这些ScreeenHeight和ScreenWidth然后为视图和布局提供高度和宽度。

         // The below two lines will use to get the MOBILE SCREEN HEIGHT && WIDTH in ViewModel
          int heightScreen=App.screenHeight;
          int widthScreen=App.screenHeigh;

XAML设计：

<强> UserLogin.xaml

   <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:local="clr-
  SreenSizeDemo;assembly=SreenSizeDemo" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
   x:Class="SreenSizeDemo.UserLogin">
  <StackLayout>
   <Label x:Name="lblTitle" HorizontalOptions="FillAndExpand"/>
   <Image x:Name="imgProfile"  Source="Logo.png" />
  <StackLayout>
  <ContentPage>

<强> UserLogin.xaml.cs

  public partial class UserLogin : BaseContentPage
  {
          // Here you get the MOBILE SCREEN HEIGHT && WIDTH
          int heightScreen=App.screenHeight;
          int widthScreen=App.screenHeight;

 public UserLogin()
     {
                       lblTitle.FontSize=height=Screen/36.8;
                     //The above value is equal to fontsize =20
                     imgProfile.HeightRequest=heightScreeen/10;
                     imgProfile. WidthRequest=heightScreeen/10;
            }
      }

C＃Design：

 public class UserLogin: ContentPage
      {
          // Here you get the MOBILE SCREEN HEIGHT && WIDTH
          int heightScreen=App.screenHeight;
          int widthScreen=App.screenHeight;

          public UserLogin()
               {
                   Label lab = new Label()
                    {
                      FontSize = heightScreen/ 36.8
                      //the above value is equal to fontsize =20
                    };

                   Image imgProfile=new Image()
                    {
                         Source="Logo.png",
                         HeightRequest=heightScreeen/10,
                         WidthRequest=heightScreeen/10
                  }
          }
     }

Answer 4

您似乎正在尝试相对于屏幕尺寸设置某些控件的高度和宽度。如果您使用的是Xamarin Forms，则可以使用Grid实现比例尺寸。关于使用Xamarin Forms的整个想法是你不必担心外形。

因此，在您的Xaml中，您可以通过以下方式使用Grid

 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:local="clr-SreenSizeDemo;assembly=SreenSizeDemo" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="SreenSizeDemo.UserLogin">
  <Grid x:Name="ContentGrid">
    <Grid.RowDefinitions>
        <!--This row will resize depending upon the size of the content within it-->
        <RowDefinition Height="Auto">
        <!--This will take 10% of  your total screen height-->
        <RowDefinition Height="0.1*">
        <!--This will take rest of the available the screen height (i.e. ScreenHeight - Row0Height - Row1Height)-->
        <RowDefinition Height="*">
    </Grid.RowDefinitions>
        <Label x:Name="lblTitle" Grid.Row="0" HorizontalOptions="FillAndExpand"/>
        <!--You don't need to set both height and width of the image, setting either of them is enough. Unless your ImageAscpect property neither of these AspectFill, AspectFit values-->
        <Image x:Name="ImgProfile" Grid.Row="1" Source="Logo.png"/>
        <!--Rest of your contents go in third row-->
    </Grid>
  <ContentPage>

在后面的代码中你可能要做的唯一事情是为标签控件设置FontSize。在这种情况下，你可以设置相对于屏幕尺寸的字体大小。网格的高度。

public UserLogin()
{
  lblTitle.FontSize = ContentGrid.Height/10;
}

此外，如果获取屏幕大小是不可避免的，我建议您使用依赖服务来获取屏幕大小，而不是使用全局静态属性

如何在共享代码中访问Android手机的屏幕宽度和高度？

4 个答案:

endregion