feat: 添加安装更新功能，支持下载并安装更新包；优化双屏控制逻辑，增强错误处理

src-tauri/src/lib.rs

@@ -24,29 +24,36 @@ fn set_dual_screen(app: AppHandle, on: bool) -> Result<String, String> {
         let _ = w.set_focus();
         return Ok("on".into());
     }
-    let mut builder = WebviewWindowBuilder::new(&app, "secondary", WebviewUrl::default())
-        .title("OPC 运营中心 · 双屏");
-    // 定位到第二块屏（非主屏；无第二屏则用第一块）
-    if let Ok(monitors) = app.available_monitors() {
-        eprintln!("[dual] available_monitors={}", monitors.len());
-        let primary_pos = app
-            .primary_monitor()
-            .ok()
-            .flatten()
-            .map(|pm| { let p = pm.position(); (p.x, p.y) });
-        eprintln!("[dual] primary_pos={:?}", primary_pos);
-        let target = monitors
-            .iter()
-            .find(|m| { let p = m.position(); Some((p.x, p.y)) != primary_pos })
-            .or_else(|| monitors.first());
-        if let Some(mon) = target {
-            let p = mon.position();
-            let s = mon.size();
-            eprintln!("[dual] target {}x{} @ {},{}", s.width, s.height, p.x, p.y);
-            builder = builder.position(p.x as f64, p.y as f64).inner_size(s.width as f64, s.height as f64);
+    // 主屏位置（用于排除主屏；必须把副窗放到主屏之外）
+    let primary_pos = app
+        .primary_monitor()
+        .ok()
+        .flatten()
+        .map(|pm| { let p = pm.position(); (p.x, p.y) });
+    // 获取全部显示器，寻找一块与主屏位置不同的副屏
+    let monitors = app.available_monitors().map_err(|e| format!("读取显示器失败: {e}"))?;
+    eprintln!("[dual] monitors={} primary_pos={:?}", monitors.len(), primary_pos);
+    let mut target: Option<(i32, i32, u32, u32)> = None; // (x, y, w, h)
+    for m in &monitors {
+        let p = m.position();
+        if Some((p.x, p.y)) != primary_pos {
+            let s = m.size();
+            target = Some((p.x, p.y, s.width, s.height));
+            break;
         }
     }
-    let win = builder.build().map_err(|e| e.to_string())?;
+    // 绝对不允许在主屏桌面上开启；没有副屏则拒绝
+    let (x, y, w, h) = match target {
+        Some(t) => t,
+        None => return Err("未检测到副屏（需连接第二块显示器），无法开启双屏".into()),
+    };
+    eprintln!("[dual] secondary {}x{} @ {},{}", w, h, x, y);
+    let win = WebviewWindowBuilder::new(&app, "secondary", WebviewUrl::default())
+        .title("OPC 运营中心 · 双屏")
+        .position(x as f64, y as f64)
+        .inner_size(w as f64, h as f64)
+        .build()
+        .map_err(|e| format!("创建副窗失败: {e}"))?;
     // 等窗口内容就绪后再全屏（避免过早全屏导致白屏/布局异常）
     let win2 = win.clone();
     std::thread::spawn(move || {
@@ -57,6 +64,28 @@ fn set_dual_screen(app: AppHandle, on: bool) -> Result<String, String> {
     Ok("on".into())
 }
 
+/// 安装更新：把前端已下载的安装包字节写入磁盘 → 启动安装程序 → 退出应用。
+/// bytes 由前端 fetch /download 得到；启动安装程序后进程独立，应用退出不影响它。
+#[tauri::command]
+fn install_update(app: AppHandle, bytes: Vec<u8>, filename: String) -> Result<String, String> {
+    if bytes.len() < 1000 {
+        return Err("下载内容无效或为空".into());
+    }
+    let dest = std::env::temp_dir().join(filename);
+    std::fs::write(&dest, &bytes).map_err(|e| format!("写入安装包失败: {e}"))?;
+    // 启动安装程序（Windows 下 Command::spawn 为独立进程，应用退出后仍在运行）
+    std::process::Command::new(&dest)
+        .spawn()
+        .map_err(|e| format!("启动安装程序失败: {e}"))?;
+    // 稍后退出应用，让安装程序接管
+    let app2 = app.clone();
+    std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(800));
+        app2.exit(0);
+    });
+    Ok(dest.to_string_lossy().into_owned())
+}
+
 /// 读取运行时配置（部署用，免重新打包）：
 ///   1) exe 同目录 config.json / dpm.config.json（最高优先）
 ///   2) 应用配置目录 config.json
@@ -98,7 +127,11 @@ pub fn run() {
             tauri_plugin_autostart::MacosLauncher::LaunchAgent,
             Some(vec![]),
         ))
-        .invoke_handler(tauri::generate_handler![read_runtime_config, set_dual_screen])
+        .invoke_handler(tauri::generate_handler![
+            read_runtime_config,
+            set_dual_screen,
+            install_update
+        ])
         .on_window_event(|window, event| {
             if let tauri::WindowEvent::CloseRequested { api, .. } = event {
                 // 仅主窗口关闭=最小化（进程常驻）；双屏副窗口可正常关闭