feat: add camera selector interface with choice of camera modes

app/src/main/AndroidManifest.xml

@@ -5,6 +5,8 @@
 
     <!-- 相机权限 -->
     <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
     
     <!-- 硬件功能声明 -->
     <uses-feature android:name="android.hardware.camera" android:required="true" />
@@ -34,6 +36,14 @@
             android:name=".WatermarkCameraActivity"
             android:exported="false"
             android:screenOrientation="portrait" />
+        <activity
+            android:name=".CameraActivity"
+            android:exported="false"
+            android:screenOrientation="portrait" />
+        <activity
+            android:name=".SettingsActivity"
+            android:exported="false"
+            android:screenOrientation="portrait" />
     </application>
 
 </manifest>

app/src/main/java/com/example/app/CameraSelectorActivity.kt

@@ -0,0 +1,34 @@
+package com.example.app
+
+import android.content.Intent
+import android.os.Bundle
+import android.widget.Button
+import androidx.appcompat.app.AppCompatActivity
+
+class CameraSelectorActivity : AppCompatActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_camera_selector)
+
+        val btnSimpleCamera = findViewById<Button>(R.id.btnSimpleCamera)
+        val btnWatermarkCamera = findViewById<Button>(R.id.btnWatermarkCamera)
+        val btnMultiCamera = findViewById<Button>(R.id.btnMultiCamera)
+        val btnSettings = findViewById<Button>(R.id.btnSettings)
+
+        btnSimpleCamera.setOnClickListener {
+            startActivity(Intent(this, SimpleCameraActivity::class.java))
+        }
+
+        btnWatermarkCamera.setOnClickListener {
+            startActivity(Intent(this, WatermarkCameraActivity::class.java))
+        }
+
+        btnMultiCamera.setOnClickListener {
+            startActivity(Intent(this, CameraActivity::class.java))
+        }
+
+        btnSettings.setOnClickListener {
+            startActivity(Intent(this, SettingsFragment::class.java))
+        }
+    }
+}

app/src/main/java/com/example/app/MainActivity.kt

@@ -2,15 +2,33 @@ package com.example.app
 
 import android.content.Intent
 import android.os.Bundle
+import android.widget.Button
 import androidx.appcompat.app.AppCompatActivity
 
 class MainActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_main)
+        setContentView(R.layout.activity_camera_selector)
 
-        // 启动带水印相机Activity
+        val btnSimpleCamera = findViewById<Button>(R.id.btnSimpleCamera)
-        startActivity(Intent(this, WatermarkCameraActivity::class.java))
+        val btnWatermarkCamera = findViewById<Button>(R.id.btnWatermarkCamera)
-        finish() // 关闭MainActivity，避免返回键回到空白页面
+        val btnMultiCamera = findViewById<Button>(R.id.btnMultiCamera)
+        val btnSettings = findViewById<Button>(R.id.btnSettings)
+
+        btnSimpleCamera.setOnClickListener {
+            startActivity(Intent(this, SimpleCameraActivity::class.java))
+        }
+
+        btnWatermarkCamera.setOnClickListener {
+            startActivity(Intent(this, WatermarkCameraActivity::class.java))
+        }
+
+        btnMultiCamera.setOnClickListener {
+            startActivity(Intent(this, CameraActivity::class.java))
+        }
+
+        btnSettings.setOnClickListener {
+            startActivity(Intent(this, SettingsActivity::class.java))
+        }
     }
 }

app/src/main/java/com/example/app/SettingsActivity.kt

@@ -0,0 +1,27 @@
+package com.example.app
+
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import androidx.preference.PreferenceFragmentCompat
+
+class SettingsActivity : AppCompatActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_settings)
+        
+        if (savedInstanceState == null) {
+            supportFragmentManager
+                .beginTransaction()
+                .replace(R.id.settings_container, SettingsFragment())
+                .commit()
+        }
+        
+        // 设置ActionBar返回按钮
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
+    }
+
+    override fun onSupportNavigateUp(): Boolean {
+        onBackPressed()
+        return true
+    }
+}

app/src/main/res/layout/activity_camera_selector.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical"
+    android:padding="16dp"
+    android:gravity="center"
+    tools:context=".CameraSelectorActivity">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="选择相机模式"
+        android:textSize="24sp"
+        android:textStyle="bold"
+        android:layout_marginBottom="48dp"
+        android:textColor="@color/black" />
+
+    <Button
+        android:id="@+id/btnSimpleCamera"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="16dp"
+        android:text="简单相机"
+        android:textSize="18sp"
+        android:padding="20dp" />
+
+    <Button
+        android:id="@+id/btnWatermarkCamera"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="16dp"
+        android:text="水印相机"
+        android:textSize="18sp"
+        android:padding="20dp" />
+
+    <Button
+        android:id="@+id/btnMultiCamera"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="16dp"
+        android:text="多图合成相机"
+        android:textSize="18sp"
+        android:padding="20dp" />
+
+    <Button
+        android:id="@+id/btnSettings"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="32dp"
+        android:text="设置"
+        android:textSize="16sp"
+        android:padding="16dp" />
+
+</LinearLayout>

app/src/main/res/layout/activity_settings.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/settings_container"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent" />