PlayerSettings.Android.defaultWindowWidth

Description

The default horizontal size of the Android Player window in pixels.

On Android phones and tablets that support multiple windows, this controls the width of the window when in the popup window mode.

using UnityEngine;
using UnityEditor;
using UnityEditor.Build;

public class DefaultWindowWidthSample : MonoBehaviour
{
    [MenuItem("Build/Default Window width Sample")]
    public static void BuildWindowWidthSample()
    {
        PlayerSettings.SetScriptingBackend(NamedBuildTarget.Android, ScriptingImplementation.IL2CPP);
        PlayerSettings.Android.targetArchitectures = AndroidArchitecture.ARM64;
        
        //Set default window width
        PlayerSettings.Android.defaultWindowWidth = 100;
        
        BuildPlayerOptions options = new BuildPlayerOptions();
        options.scenes = new[] { "Assets/Scenes/SampleScene.unity" };
        options.locationPathName = "Build/AndroidBuild.apk";
        options.target = BuildTarget.Android;
        options.targetGroup = BuildTargetGroup.Android;
        BuildPipeline.BuildPlayer(options);
    }
}