11.17

1. js文件： onclick函数return True时才提交表单，return False时不提交表单。

   function foLogin() {
               var oUname = document.getElementById("uname");
               var oError = document.getElementById("error_box");
               var oUpass = document.getElementById("upass");
               var oUpass1=document.getElementById("upass1");
               var isoError = true;
               oError.innerHTML = "<br>";
   
               if (oUname.value.length < 6 || oUname.value.length > 20) {
                   oError.innerHTML = "用户名要6-20位";
                   isoError = false;
                   return isoError;
               }else if((oUname.value.charCodeAt(0)<=48)&&(oUname.value.charCodeAt(0)>=57)){
                   oError.innerHTML="首字母不能为数字";
                   isoError = false;
                   return isoError;
               }else for(var i=0;i<oUname.value.length;i++){
                   if((oUname.value.charCodeAt(i)<48||oUname.value.charCodeAt(i)>57)&&(oUname.value.charCodeAt(i)<97||oUname.value.charCodeAt(i)>122)){
                       oError.innerHTML="只能包含字母和数字";
                       isoError = false;
                       return isoError;
                   }
               }
   
               if (oUpass.value.length < 6 || oUpass.value.length > 20){
                   oError.innerHTML = "密码要6-20位";
                   isoError = false;
                   return isoError;
               }
               if(oUpass.value()!=oUpass1.value()){
                   oError.innerHTML="两次密码不一致";
                   isoError = false;
                   return isoError;
               }
               window.alert("注册成功！！")
               return true;
   
           }

   html文件：

   1. <form>中设置 action和method="post"
   2. <input> 中设置 name

       <form action="{{ url_for('zhuce') }}" method="post">
                  <div class="input_box">
                      用户名： <input id="uname" type="text" placeholder="请输入用户名" name="username">
      {#                昵称：<input id="unickname" type="text" placeholder="昵称" name="nickname">#}
                  </div>
                  <div class="input_box">
                      密码： <input id="upass" type="password" placeholder="请输入密码" name="password">
                  </div>
                  <div class="input_box ">
                      密码：<input id="upass1" type="password" placeholder="请再次输入密码">
                  </div>
                  <div id="error_box"><br></div>
                  <div class="input_box">
                      <button onclick="foLogin()">注册</button>
                  </div>
              </form>

      1. 主py文件中：
         1. from flask import  request, redirect, url_for
         2. @app.route('/regist/', methods=['GET', 'POST’])

      def regist():

         if request.method == 'GET':

              return render_template('regist.html')

         else:

              username = request.form.get(‘username’)#获取form中的数据

              判断用户名是否存在

              存到数据库中

              redirect重定向到登录页

      @app.route('/zhuce',methods=['GET','POST'])
      def zhuce():
          if request.method=='GET':
              return render_template('zhuce.html')
          else:
              username=request.form.get('username')
              password=request.form.get('password')
              # nickname=request.form.get('nickname')
              user=User.query.filter(User.username==username).first()
              if user:
                  return 'username existed'
              else:
                  user=User(username=username,password=password)
                  db.session.add(user)
                  db.session.commit()
                  return redirect(url_for('denglu'))