#command、bind()、class_bind()三种事件方式绑定测试

from tkinter import *
root=Tk()
root.geometry('200x200')
root.title('测试三种事件绑定方式')
def textcommand(a,b):
    print('测试command方式绑定，不能直接获取事件对象')
    print('{0}+{1}'.format(a,b))
def textbind(event):
    print('bind()绑定方式，可以获取事件对象')
    print(event.widget)
def textClassbind(event):
    print('右键单击事件，绑定给所有按钮')
    print(event.widget)
b1=Button(root,text='测试command',command=lambda :textcommand('love','hate'))
b1.pack(side='left')
b2=Button(root,text='测试bind()')
b2.pack(side='left')
b2.bind('<1>',textbind)
b2.bind_class('Button','<Button-2>',textClassbind)
root.mainloop()

运行之后用鼠标右键按了没反应，是哪里出错了吗？

老师 Entry 是啥意思

console.log(''.concat()one,two,three)''有什么意义？

1

package com.bjsxt.test;

public class TestString {
    public static void main(String[] args) {
        String str = "aabb";        //不可变字符序列
        StringBuilder sb = null;    //可变字符序列，线程不安全，效率高
        StringBuffer sb2 = null;   //可变字符序列，线程安全，效率低

        sb = new StringBuilder("yao");

        sb.append(123);
        sb.append(456);
        System.out.println(sb);
    }
}

sb = new StringBuilder("yao");

这句话是什么意思？

package com.itbaizhan;

import java.sql.Connection;
import java.sql.Statement;

/**
 * Statement对象的使用
 */
public class statementTest {
    /**
     * 添加用户
     */
    public void insertUsers(String username,int userage){
        Connection connection=null;
        Statement statement=null;
        try {
            //获取Connection对象
            connection=JdbcUtils.getConnection();
            //获取Statement对象
            statement=connection.createStatement();
            //定义需要执行的SQL语句
            String sql = "insert into users values(default,' "+username+" ',"+userage+")";
            //执行SQL,返回boolean值，如果sql有结果集返回，那么返回值为true，如果没有结果集返回，则返回false。
            boolean execute= statement.execute(sql);
            System.out.println(execute);

        }catch (Exception e){
            e.printStackTrace();
        }finally {
        JdbcUtils.closeResource(statement,  connection);
        }

    }
}



package com.itbaizhan;

import java.sql.Statement;

public class Test {
    public static void main(String[] args) {
        statementTest st=new statementTest();
        st.insertUsers("ccc",18);
    }
}

哪里有错误呢

import pygame
from pygame.sprite import Sprite
import time
import random
SCREEN_WIDTH=700
SCREEN_HEIGHT=500
BG_COLOR=pygame.Color(0,0,0)
TEXT_COLOR=pygame.Color(255,0,0)
class BaseItem(Sprite):
    def __init__(self,color,width,height):
        pygame.sprite.Sprite.__init__(self)

class Maingame():
    window=None
    my_tank=None
    enemyTankList=[]
    enemyTankcount=5
    myBulletList=[]
    enemyBulletList=[]
    explodeList=[]
    def createEnemyTank(self):
       top=100

       #循环生成敌方坦克
       for i in range(Maingame.enemyTankcount):

           left=random.randint(0,600)
           speed=random.randint(1,4)

           enemy=Enemytank(left,top,speed)
           Maingame.enemyTankList.append(enemy)
    def blitEnemyTank(self):
        #判断敌方坦克是否活着

        for enemyTank in Maingame.enemyTankList:
            if enemyTank.live:
                enemyTank.displayTank()
                enemyTank.randMove()
                enemyBullet=enemyTank.shot()
                if enemyBullet:
                    Maingame.enemyBulletList.append(enemyBullet)
            else:
                Maingame.enemyTankList.remove(enemyTank)


    def blitMyBullet(self):
        #判断当前子弹是否为活着的状态，如果不是则在列表中删除

        for myBullet in Maingame.myBulletList:
            if myBullet.live:
                myBullet.displayBullet()
                myBullet.move()
                myBullet.myBullet_hit_enemyTank()
            else:
                Maingame.myBulletList.remove(myBullet)
    def blitEnemyBullet(self):
        for enemyBullet in Maingame.enemyBulletList:
            if enemyBullet.live:

                enemyBullet.displayBullet()
                enemyBullet.move()

            else:
                Maingame.enemyBulletList.remove(enemyBullet)




    def  __init__(self):
       pass
    def startgame(self):
        pygame.display.init()
        Maingame.window = pygame.display.set_mode([SCREEN_WIDTH, SCREEN_HEIGHT])
        pygame.display.set_caption("坦克大战1.03")
        Maingame.my_tank=Tank(350,250)
        self.createEnemyTank()
        while True:
            time.sleep(0.02)
            pygame.display.update()
            Maingame.window.fill(BG_COLOR)
            Maingame.window.blit(self.getTextSurface("敌方坦克剩余数量%d"%len(Maingame.enemyTankList)),(10,10))# 后一个位置可接元组
            self.getEvent()
            Maingame.my_tank.displayTank()
            self.blitEnemyTank()
            self.blitMyBullet()
            self.blitEnemyBullet()
            self.blitExplode()
    def blitExplode(self):
        for explode in Maingame.explodeList:
            if explode.live:
                explode.displayExplode()
            else:
                Maingame.explodeList.remove(explode)
            if not Maingame.my_tank.stop:
                Maingame.my_tank.move()

    def endgame(self):
        print("谢谢使用哦")
        exit()
    def getEvent(self):
        eventList=pygame.event.get()
        for event in eventList:
            if event.type == pygame.QUIT:
                self.endgame()
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT:
                    Maingame.my_tank.direction="L"
                    Maingame.my_tank.stop=False
                    #Maingame.my_tank.move()
                    print("坦克向左移动")
                elif event.key == pygame.K_UP:
                    Maingame.my_tank.direction = "U"
                    Maingame.my_tank.stop=False

                    #Maingame.my_tank.move()
                    print("坦克向上移动")
                elif event.key == pygame.K_RIGHT:
                    Maingame.my_tank.direction = "R"
                    Maingame.my_tank.stop = False
                    #Maingame.my_tank.move()
                    print("坦克向右移动")
                elif event.key == pygame.K_DOWN:
                    Maingame.my_tank.direction = "D"
                    Maingame.my_tank.stop = False
                    print("坦克向下移动")
                elif event.key == pygame.K_SPACE:
                    print("发射子弹")
                    #Maingame.my_tank.move()
                    if len(Maingame.myBulletList)<=3:
                        myBullet=Bullet(Maingame.my_tank)
                        Maingame.myBulletList.append(myBullet)

            if event.type == pygame.KEYUP:
                if event.key== pygame.K_UP or event.key==pygame.K_DOWN or event.key==pygame.K_RIGHT or event.key==pygame.K_LEFT:
                    Maingame.my_tank.stop=True

    def getTextSurface(self,text):
        #初始化字体模块
        pygame.font.init()
        font=pygame.font.SysFont("kaiti",18)
        textSurface=font.render(text,True,TEXT_COLOR)
        return textSurface




class Tank(BaseItem):
    def __init__(self,top,left):
        self.images={
            "U":pygame.image.load("imgs/p1tankU.gif"),
            "D": pygame.image.load("imgs/p1tankD.gif"),
            "L": pygame.image.load("imgs/p1tankL.gif"),
            "R": pygame.image.load("imgs/p1tankR.gif")

        }
        self.direction="U"
        self.image=self.images[self.direction]
        self.rect=self.image.get_rect()
        self.rect.left=left
        self.rect.top=top
        self.speed=10
        self.stop = True
        self.live = True

    def move(self):
        if self.direction =="L":
            if self.rect.left>0:
               self.rect.left -= self.speed
        elif self.direction =="U":
            if self.rect.top>0:
               self.rect.top -= self.speed
        elif self.direction =="D":
            if self.rect.top+self.rect.height<SCREEN_HEIGHT:
               self.rect.top += self.speed
        elif self.direction =="R":
            if self.rect.left+self.rect.height<SCREEN_WIDTH:
                self.rect.left += self.speed
    def shot(self):
        return Bullet(self)
    def displayTank(self):
        self.image=self.images[self.direction]
        Maingame.window.blit(self.image,self.rect)
#我方坦克
class Mytank():
    def __init__(self):
        pass
class Enemytank(Tank):
    def __init__(self,left,top,speed):
        super(Enemytank,self).__init__(left,top)
        self.images={"U":pygame.image.load("imgs/enemy1U.gif"),
                     "R": pygame.image.load("imgs/enemy1R.gif"),
                     "L":pygame.image.load("imgs/enemy1L.gif"),
                     "D":pygame.image.load("imgs/enemy1D.gif")
                     }
        self.direction=self.randDirection()
        self.image = self.images[self.direction]
        self.rect=self.image.get_rect()
        self.rect.left=left
        self.rect.top=top
        self.speed=speed
        self.flag=True
        self.step=60



    def randDirection(self):
        num = random.randint(1,4)
        if num==1:
            return "U"
        elif num ==2:
            return "R"
        elif num ==3:
            return  "L"
        elif num==4:
            return "D"
    #敌方坦克随机移动的方法
    def randMove(self):
        if self.step <=0:
            self.direction=self.randDirection()
            self.step=60
        else:
            self.move()
            self.step-=1
    def shot(self):
        num=random.randint(1,100)
        if num <10:
            return Bullet(self)

class Wall():
    def __init__(self):
        pass
    def display(self):
        pass
class Explode():
    #爆炸同tank的位置相同
    def __init__(self,tank):
        self.rect= tank.rect
        self.images=[pygame.image.load("imgs/blast0.gif"),
                     pygame.image.load("imgs/blast1.gif"),
                     pygame.image.load("imgs/blast2.gif"),
                     pygame.image.load("imgs/blast3.gif"),
                     pygame.image.load("imgs/blast4.gif"),

        ]
        self.step=0
        self.image=self.images[self.step]
        self.live=True

    def displayExplode(self):
        if self.step <len(self.images):
            self.image=self.images[self.step]
            self.step+=1
            Maingame.window.blit(self.image,self.rect)
        else:
            self.live=False
            self.step=0

class music():
    def __init__(self):
        pass
    def play(self):
        pass
class Bullet(BaseItem):
    def __init__(self,tank):
        self.image=pygame.image.load("imgs/enemymissile.gif")

        self.direction= tank.direction
        self.rect=self.image.get_rect()
        if self.direction=="U":
            self.rect.left= tank.rect.left+tank.rect.width/2-self.rect.width/2
            self.rect.top = tank.rect.top-self.rect.top
        elif self.direction=="D":
            self.rect.left= tank.rect.left+tank.rect.width/2-self.rect.width/2
            self.rect.top = tank.rect.top+self.rect.top
        elif self.direction=="L":
            self.rect.left= tank.rect.left-tank.rect.width/2-self.rect.width/2
            self.rect.top = tank.rect.top+tank.rect.width/2-self.rect.width/2
        elif self.direction=="R":
            self.rect.left= tank.rect.left+tank.rect.width
            self.rect.top = tank.rect.top+tank.rect.width/2-self.rect.width/2

        self.speed=6
        #增加子弹的状态是否碰到墙壁
        self.live=True

    def displayBullet(self):
        Maingame.window.blit(self.image,self.rect)
    def move(self):
        if self.direction =="U":
            if self.rect.top >0:
                self.rect.top -=self.speed
            else:
                self.live=False
        elif self.direction == "R":
            if self.rect.left+self.rect.width<SCREEN_WIDTH:
                self.rect.left+=self.speed
            else:
                self.live=False
        elif self.direction == "L":
            if self.rect.left>0:
                self.rect.left-=self.speed
            else:
                self.live=False
        elif self.direction == "D":
            if self.rect.top+self.rect.height<SCREEN_HEIGHT:
                self.rect.top+=self.speed
            else:
                self.live=False
    #我方子弹与敌方坦克的碰撞
    def myBullet_hit_enemyTank(self):
        for enemyTank in Maingame.enemyTankList:
            if pygame.sprite.collide_rect(enemyTank,self):
                enemyTank.live=False
                self.live=False
                explode=Explode(enemyTank)
                Maingame.explodeList.append(explode)





if __name__== '__main__':
    Maingame().startgame()
 
 
#老师，请问我这个代码跑的时候为什么会出现我方坦克只能打中对方才能移动的情况呢

老师 为什么直接再div元素选择器中加宽和高不生效?

老师，您好,为什么我的python turtle graphics不能和python IDLE同时运行，该怎样修改呢？谢谢老师

我感觉策略模式和之前学的静态代理模式好像

老师这个为什么从大到小排列可以三个全部输出 

从小到大 第三个为空了 这是为什么啊

Test_4 是User 

（1）“h”“中”类似于这个双引号里面只有一个英文字母或中文汉字，这也叫字符串吗？

（2）到底什么才能叫字符串？

老师，我对一个类重写了，但是没有报任何结果

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>cookie复杂存储</title>
</head>
<body>
    <button>点我</button>
    <script>

        (function() {
            var xhr=window.XMLHttpRequest
            ?new XMLHttpRequest()
            :new ActiveXObject();
            xhr.onreadystatechange=function() {
                if(xhr.readyState==4) {
                    if(xhr.status==200) {
                        console.log(xhr.responseText)
                    }
                }
            }
            var datas=new FormData();
            datas.append('name','taige');
            datas.append('hobby','eat');
            xhr.open('post','cookie后台.php',true);
            xhr.send(datas);
        }());
    </script>
</body>
</html>

<?php
    // 处理cookie
    $name=$_POST['name'];
    $hobby=$_POST['hobby'];
    setcookie('name',$name,time()+60*60);
    setcookie('hobby',$hobby,time(+60*60));

    // 给出反馈
    $success=array('msg'=>'ok');
    echo json_encode($success);
?>

老师，我前后台数据都提交了，您看看。我返回的结果是这玩意！！

老师，1.正例样本是候选框吗？

2.NMS之后，再取Top-N，假如取100个，那么这100个和128个正样本之间什么关系？

可以说，这100个就在正样本里面吗？如果在，为什么不直接向后传正样本里面的数据？

老师引入 vue add element 就报错