修复 bug

src/App.vue

@@ -59,7 +59,13 @@
       </div>
       <b-form class="d-flex m-3" @submit.prevent="sendMessage">
         <b-form-input class="flex-fill mr-2" v-model="message"> </b-form-input>
-        <b-button pill variant="success" type="submit">Button</b-button>
+        <b-button
+          :disabled="message.length == 0"
+          pill
+          variant="success"
+          type="submit"
+          >Send</b-button
+        >
       </b-form>
     </div>
   </div>
@@ -89,7 +95,7 @@ export default class App extends Vue {
     if (chineseChar.test(firstChar)) {
       return firstChar;
     } else {
-      return this.nickname.substring(0, 2);
+      return nickname.substring(0, 2);
     }
   }
   public login(): void {
@@ -105,6 +111,7 @@ export default class App extends Vue {
   }
   public sendMessage(): void {
     ipcRenderer.send("message", this.message);
+    this.message = "";
   }
   mounted(): void {
     ipcRenderer.on("message", (_, nickname, message) => {