feat: add image picker utility and integrate image upload in DynamicForm component

lib/imgPicker.ts

@@ -0,0 +1,82 @@
+import * as ImagePicker from 'expo-image-picker'
+import Toast from '@/components/ui/Toast'
+
+// 定义图片选择器参数类型
+type PickerBaseParams = Omit<
+  ImagePicker.ImagePickerOptions,
+  'mediaTypes' | 'allowsMultipleSelection' | 'selectionLimit'
+> & {
+  /** 最大选择图片数量，默认 1 */
+  maxImages?: number
+  /** 媒体类型，默认仅图片 */
+  type?: ImagePicker.MediaTypeOptions
+}
+
+type PickerUriParams = PickerBaseParams & {
+  /** 返回类型：uri 返回字符串数组 */
+  resultType?: 'uri'
+}
+
+type PickerAssetParams = PickerBaseParams & {
+  /** 返回类型：asset 返回完整资源对象 */
+  resultType: 'asset'
+}
+
+/**
+ * 图片选择器工具
+ * 直接打开系统相册选择图片
+ *
+ * @example
+ * // 选择单张图片，返回 URI
+ * const [uri] = await imgPicker({ maxImages: 1 })
+ *
+ * // 选择多张图片，返回 URI 数组
+ * const uris = await imgPicker({ maxImages: 9 })
+ *
+ * // 返回完整资源对象（包含宽高等信息）
+ * const assets = await imgPicker({ maxImages: 1, resultType: 'asset' })
+ */
+export async function imgPicker(params: PickerUriParams): Promise<string[]>
+export async function imgPicker(params: PickerAssetParams): Promise<ImagePicker.ImagePickerAsset[]>
+export async function imgPicker(
+  params: PickerUriParams | PickerAssetParams
+): Promise<string[] | ImagePicker.ImagePickerAsset[]> {
+  const {
+    maxImages = 1,
+    type = ImagePicker.MediaTypeOptions.Images,
+    resultType = 'uri',
+    ...rest
+  } = params
+
+  const isMultiple = maxImages > 1
+
+  // 请求相册权限
+  const { status } = await ImagePicker.requestMediaLibraryPermissionsAsync()
+  if (status !== 'granted') {
+    Toast.show('请开启相册权限')
+    throw new Error('请开启相册权限')
+  }
+
+  // 打开相册选择图片
+  const result = await ImagePicker.launchImageLibraryAsync({
+    mediaTypes: type,
+    quality: 0.9,
+    allowsMultipleSelection: isMultiple,
+    selectionLimit: maxImages,
+    ...rest,
+  })
+
+  // 用户取消选择
+  if (result.canceled || !result.assets?.length) {
+    throw new Error('未选择任何图片')
+  }
+
+  // 根据 resultType 返回不同格式
+  if (resultType === 'uri') {
+    return result.assets.map((asset) => asset.uri)
+  }
+
+  return result.assets
+}
+
+export default imgPicker