优化UI

app/src/main/java/com/example/defenseapplication/home/HomeMenuFragment.kt

@@ -1,12 +1,17 @@
 package com.example.defenseapplication.home
 
+import android.graphics.Color
+import android.graphics.Rect
+import android.graphics.drawable.GradientDrawable
 import android.os.Bundle
+import android.util.TypedValue
 import androidx.fragment.app.Fragment
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
 import com.example.defenseapplication.adapter.DeviceAdapter
 import com.example.defenseapplication.adapter.DeviceUi
 import com.example.defenseapplication.adapter.FamilyAdapter
@@ -49,6 +54,17 @@ class HomeMenuFragment : Fragment() {
         return binding.root
     }
 
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        // 为 LinearLayout 设置渐变背景
+        setGradientBackground(
+            view = binding.gradientLayout,
+            startColor = Color.parseColor("#EBDCED"),
+            endColor = Color.parseColor("#CAF4FF")
+        )
+    }
+
     private fun initView() {
         binding.rvFamilyList.layoutManager = LinearLayoutManager(requireContext())
         binding.rvFamilyList.adapter = familyAdapter
@@ -56,6 +72,11 @@ class HomeMenuFragment : Fragment() {
 
         binding.rvDeviceList.layoutManager = GridLayoutManager(requireContext(), 2)
         binding.rvDeviceList.adapter = deviceAdapter
+        if (binding.rvDeviceList.itemDecorationCount == 0) {
+            binding.rvDeviceList.addItemDecoration(
+                GridHorizontalSpaceItemDecoration(horizontalSpace = dpToPx(8))
+            )
+        }
         updateDeviceList()
 
         binding.tvCurrentFamily.text = currentFamily
@@ -94,6 +115,45 @@ class HomeMenuFragment : Fragment() {
         deviceAdapter.submitList(familyDeviceMap[currentFamily].orEmpty())
     }
 
+    private fun dpToPx(dp: Int): Int {
+        return TypedValue.applyDimension(
+            TypedValue.COMPLEX_UNIT_DIP,
+            dp.toFloat(),
+            resources.displayMetrics
+        ).toInt()
+    }
+
+    private class GridHorizontalSpaceItemDecoration(
+        private val horizontalSpace: Int
+    ) : RecyclerView.ItemDecoration() {
+        override fun getItemOffsets(
+            outRect: Rect,
+            view: View,
+            parent: RecyclerView,
+            state: RecyclerView.State
+        ) {
+            val position = parent.getChildAdapterPosition(view)
+            if (position == RecyclerView.NO_POSITION) return
+
+            if (position % 2 == 0) {
+                outRect.right = horizontalSpace / 2
+            } else {
+                outRect.left = horizontalSpace / 2
+            }
+        }
+    }
+
+    private fun setGradientBackground(
+        view: View,
+        startColor: Int,
+        endColor: Int,
+        orientation: GradientDrawable.Orientation = GradientDrawable.Orientation.TL_BR
+    ) {
+        val gradientDrawable = GradientDrawable(orientation, intArrayOf(startColor, endColor))
+        gradientDrawable.gradientType = GradientDrawable.LINEAR_GRADIENT
+        view.background = gradientDrawable
+    }
+
     override fun onDestroyView() {
         super.onDestroyView()
         binding.rvFamilyList.adapter = null