优化

src/api/overseas.js

@@ -174,7 +174,9 @@ export async function overseasDownload(path, options = {}) {
 		throw errorFrom({ ...response, data: {} }, '签收照片下载失败')
 	}
 	const contentType = String(response?.header?.['content-type'] || response?.header?.['Content-Type'] || '').toLowerCase()
-	if (expectedContentTypePrefix && !contentType.startsWith(expectedContentTypePrefix.toLowerCase())) {
+	// App-Plus downloadFile may omit response headers even when the image body was downloaded successfully.
+	// Reject an explicit non-image response, but allow a valid temp file when Content-Type is unavailable.
+	if (expectedContentTypePrefix && contentType && !contentType.startsWith(expectedContentTypePrefix.toLowerCase())) {
 		throw errorFrom({ ...response, data: {} }, '照片服务返回了无效内容，请稍后重试')
 	}
 	return response.tempFilePath

tests/overseas-request.test.mjs

@@ -274,6 +274,20 @@ test('authenticated photo download maps the public api path through the H5 overs
 	assert.equal(calls[0].header.Authorization, `Bearer ${value.overseasAccessToken}`)
 })
 
+test('native image download accepts a valid temp file when App-Plus omits response headers', async () => {
+	prepareSession()
+	globalThis.uni.downloadFile = (options) => options.success({
+		statusCode: 200,
+		tempFilePath: '_doc/uniapp_temp/photo.jpg',
+		header: {}
+	})
+
+	assert.equal(
+		await overseasDownload('/api/pda/v1/last-leg/photo', { expectedContentTypePrefix: 'image/' }),
+		'_doc/uniapp_temp/photo.jpg'
+	)
+})
+
 test('image download rejects a JSON error envelope returned with HTTP 200', async () => {
 	prepareSession()
 	globalThis.uni.downloadFile = (options) => options.success({