C# 看不懂,public void frmBooksql(){//打开数据库SqlConnection mySqlConnection = new SqlConnection(Conn);mySqlConnection.Open();string sqlQuery = "SELECT * FROM Book";SqlCommand mySqlCommand = new SqlCommand(sqlQuery,mySqlConnection);mySqlComma

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/09 10:28:55

C# 看不懂,public void frmBooksql(){//打开数据库SqlConnection mySqlConnection = new SqlConnection(Conn);mySqlConnection.Open();string sqlQuery = "SELECT * FROM Book";SqlCommand mySqlCommand = new SqlCommand(sqlQuery,mySqlConnection);mySqlComma
C# 看不懂,
public void frmBooksql()
{
//打开数据库
SqlConnection mySqlConnection = new SqlConnection(Conn);
mySqlConnection.Open();
string sqlQuery = "SELECT * FROM Book";
SqlCommand mySqlCommand = new SqlCommand(sqlQuery,mySqlConnection);
mySqlCommand.ExecuteNonQuery();
SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter(mySqlCommand);
//填充数据库
DataSet myDs = new DataSet();
mySqlDataAdapter.Fill(myDs);
//关闭数据库
mySqlConnection.Close();
this.dgvBook.DataSource = myDs.Tables[0];
}
private void dgvBook_DataError(object sender,DataGridViewDataErrorEventArgs e)
{
if (e.Exception = null &&
e.Context == DataGridViewDataErrorContexts.Commit)
{
MessageBox.Show("CustomerID value must be unique.");
}
}
private int DoDelete(string paramNo)
{
int returnValue = 0;
BUBook myBUBook = new BUBook();
returnValue = myBUBook.BUDelete(paramNo);
return returnValue;
}
private void Search(string paramNo,string paramName,string paramTyre,string paramState)
{
BUBook myBUBook = new BUBook();
DataTable myDataTable = new DataTable();
myDataTable = myBUBook.BUSearch(paramNo,paramName,paramTyre,paramState);
this.dgvBook.DataSource = myDataTable;
}
private void CheckBike_Load(object sender,EventArgs e)
{
frmBooksql();
BUBook myBUBook = new BUBook();
DataTable myDt = new DataTable();
myDt = myBUBook.BUTyre();
this.cmbTyre.DataSource = myDt;
this.cmbTyre.DisplayMember = "Tyre";
this.cmbTyre.ValueMember = "Tyre";
this.cmbTyre.SelectedValue.ToString();
this.cmbTyre.Text = "";
}
private void btFind_Click(object sender,EventArgs e)
{
string paramNo = this.txtNo.Text.Trim();
string paramName = this.txtName.Text.Trim();
string paramTyre = this.cmbTyre.Text.ToString();
string paramState = this.cmbState.Text.ToString();
this.Search(paramNo,paramName,paramTyre,paramState);
}
private void bt1Home_Click(object sender,EventArgs e)
{
frmintroduction myfrmintroduction = new frmintroduction();
myfrmintroduction.Show();
this.Hide();
this.DialogResult = DialogResult.No;
}
}

C# 看不懂,public void frmBooksql(){//打开数据库SqlConnection mySqlConnection = new SqlConnection(Conn);mySqlConnection.Open();string sqlQuery = "SELECT * FROM Book";SqlCommand mySqlCommand = new SqlCommand(sqlQuery,mySqlConnection);mySqlComma
这是数据库操作...不晓得你是哪里不懂的

c# base的意义public abstract class B { public B(D t) { Console.WriteLine(B); } public void K() { Console.WriteLine(K); } } public class C : B { public C(String C# 看不懂,public void frmBooksql(){//打开数据库SqlConnection mySqlConnection = new SqlConnection(Conn);mySqlConnection.Open();string sqlQuery = SELECT * FROM Book;SqlCommand mySqlCommand = new SqlCommand(sqlQuery,mySqlConnection);mySqlComma C#中的中括号是什么意思比如:[Obsolete]public void test(){……}告诉我在C#里是属于哪一课的内容 c#弄了简单计算器,想问如何多次运算.double a, b; double flag; public Form1() { InitializeComponent(); } private void button10_Click(object sender, EventArgs e) { textBox1.Te c# 根据名称如何找变量public void getval(string parm1,string parm2, string parm3, ...,int i ){//这里我如何根据i得到 参数 parm+i 的值?} 谁知道这个事务控制是怎样解释和操作的么?我看不懂?//事务控制public void beginTransaction() throws SQLException{conn.setAutoCommit(false); //有何作用?inTransaction = true;//有何作用?}public void commit() throws SQLExce 会c#的麻烦进来帮下忙using System;using System.Collections.Generic;using System.Text;namespace 类{class Dog{/* static void Main(){Dog Haba = new Dog();Haba.eat();Haba.sound();}*/public void eat(){Console.WriteLine(吃啊!);}public void sou c# public ObservableCollection icons = new ObservableCollection(); 在c++中类的派生的含义是什么?#include class CBOX{public:void f(){};void print(){};private:int length;int width;int height;};class ColorBox:public CBOX{public:void show(){};private:int color;};void main(){CBOX a;ColorBox b;b.show();}请问a 求大神帮我看看程序的运算结果#includeusing namespace std;class AA{public:virtual void f(){cout #include class A { public:void print1() { cout 程序有点看不懂,void f(int n,char x,char y,char z){if(n c#如何让把类作为参数传递?比如class test{public void tt(){//添加代码}}class B{public set(test t){t.tt()}class Main{static void gg(){B b= new B();b.set(new test())}}这样可以吗? c#里面构造函数 class A { public void A(int x){} } 可以这样吗?是构造函数吗class A { int x; public void A(){console.writeline(“{0}”,x);} }这个叫默认构造函数,它不是构造函数吧? a.b += new C(d); 在C# 这里面这么写啥意思?+= new 这样写有啥意义?初学者求教下public void asb(A a) {a.b += new C(d); } c# Console.WriteLine({0,-4},m);和Console.一部分程序是这样的:public static void Main(){ int m,k,n=1;Console.WriteLine({0,-4},2);for(m=3,m c# Flush()的问题//// 摘要:// 当在派生类中被重写时,将缓冲区中的所有内容刷新到基础流,并同时刷新基础流.public abstract void Flush();啥意思啊?我不能上QQ~ c#中的构造函数不是不能被继承的吗!为什么以下的先执行(继承)构造函数?using System;public class ParentClass{public ParentClass(){Console.WriteLine(父类构造函数.);}public void print(){ Console.WriteLine(I'm a Par