2026-05-18-19-19-36 修复样例加载提示和favicon

frontend/app.js

@@ -46,9 +46,11 @@ function setBusy(isBusy, text = "运行分割") {
 
 function setFile(file) {
   selectedFile = file;
-  const transfer = new DataTransfer();
-  transfer.items.add(file);
-  fileInput.files = transfer.files;
+  if (typeof DataTransfer !== "undefined") {
+    const transfer = new DataTransfer();
+    transfer.items.add(file);
+    fileInput.files = transfer.files;
+  }
   fileName.textContent = `${file.name} · ${(file.size / 1024 / 1024).toFixed(2)} MB`;
   renderPreview(file);
 }
@@ -180,15 +182,22 @@ function renderResults(data) {
 async function loadSample() {
   sampleButton.disabled = true;
   sampleButton.textContent = "加载中";
+  emptyState.hidden = false;
+  emptyState.textContent = "正在加载内置样例视频。";
   try {
     const response = await fetch("/api/samples");
+    if (!response.ok) throw new Error("样例清单读取失败");
     const data = await response.json();
     const sample = data.samples.find((item) => item.kind === "video") || data.samples[0];
     if (!sample) throw new Error("未找到样例文件");
     const blobResponse = await fetch(sample.url);
+    if (!blobResponse.ok) throw new Error("样例文件下载失败");
     const blob = await blobResponse.blob();
     const file = new File([blob], sample.name, { type: sample.kind === "video" ? "video/mp4" : "image/png" });
     setFile(file);
+    emptyState.textContent = "样例已加载。点击左侧“运行分割”即可生成导丝掩膜和叠加结果。";
+  } catch (error) {
+    emptyState.textContent = error.message || "样例加载失败";
   } finally {
     sampleButton.disabled = false;
     sampleButton.textContent = "加载样例";