desc: 修改快速入口提示问题

src/views/demonstration/deomonList/index.vue

@@ -103,6 +103,7 @@ export default {
 
 		},
 		async handleJoin() {
+			if (this.group) {
 				await getjointTraining(this.group);
 				if (this.state == '02') {
 					launchFullscreen();
@@ -114,6 +115,9 @@ export default {
 					const query = { group: this.group };
 					this.$router.push({ path: `/trainroom`, query: query });
 				}
+			} else {
+				this.$message.info('您没有选择房间');
+			}
 		}
 	}
 };