diff --git a/Fire/AppDelegate.swift b/Fire/AppDelegate.swift
index 72eccd1..b6c21c3 100644
--- a/Fire/AppDelegate.swift
+++ b/Fire/AppDelegate.swift
@@ -20,8 +20,8 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         InputSource.shared.activateInputSource()
         NSApp.terminate(nil)
     }
-
-    func applicationDidFinishLaunching(_ aNotification: Notification) {
+    
+    private func commandHandler() {
         if CommandLine.arguments.count > 1 {
             print("[Fire] launch argument: \(CommandLine.arguments[1])")
             let command = CommandLine.arguments[1]
@@ -34,6 +34,10 @@ class AppDelegate: NSObject, NSApplicationDelegate {
                 return NSApp.terminate(nil)
             }
         }
+    }
+
+    func applicationDidFinishLaunching(_ aNotification: Notification) {
+        commandHandler()
         if !hasDict() {
             NSLog("[Fire] first run，build dict")
             buildDict()
diff --git a/Fire/FireInputController.swift b/Fire/FireInputController.swift
index e08bf2d..73fbd50 100644
--- a/Fire/FireInputController.swift
+++ b/Fire/FireInputController.swift
@@ -49,7 +49,7 @@ class FireInputController: IMKInputController {
         if let attributes = attrs as? [NSAttributedString.Key: Any] {
             var selected = self._originalString
             if Defaults[.showCodeInWindow] {
-                selected = self._originalString.count > 1 ? " " : ""
+                selected = self._originalString.count > 0 ? " " : ""
             }
             let text = NSAttributedString(string: selected, attributes: attributes)
             client()?.setMarkedText(text, selectionRange: selectionRange(), replacementRange: replacementRange())
@@ -164,7 +164,7 @@ class FireInputController: IMKInputController {
         // 获取输入的字符
         let string = event.characters!
         // 当前输入的是数字,选择当前候选列表中的第N个字符 v
-        if let pos = Int(string) {
+        if let pos = Int(string), _originalString.count > 0 {
             let index = pos - 1
             let candidates = self.getCandidates(self)
             if index < candidates.count {
@@ -180,7 +180,7 @@ class FireInputController: IMKInputController {
 
     private func enterKeyHandler(event: NSEvent) -> Bool? {
         // 回车键输入原字符
-        if event.keyCode == kVK_Return {
+        if event.keyCode == kVK_Return && _originalString.count > 0 {
             // 插入原字符
             _composedString = _originalString
             insertText(self)
@@ -191,7 +191,7 @@ class FireInputController: IMKInputController {
 
     private func spaceKeyHandler(event: NSEvent) -> Bool? {
         // 空格键输入转换后的中文字符
-        if event.keyCode == kVK_Space {
+        if event.keyCode == kVK_Space && _originalString.count > 0 {
             if let first = self.getCandidates(self).first {
                 _composedString = first.text
                 insertText(self)