1、这是第一个版本,文件路径需要用户输入,下个版本打开即加载
2、重点学习FolderBrowserDialog控件
3、注意内容在再次打开之前,清除上次的数据内容,使用using和函数代替字符串,都是为了数据的安全性考虑
代码如下:
namespace 车牌查询
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load_1(object sender, EventArgs e)
{
cbxSheng.Items.Add("安徽省"); //这里知道文件里面只有三个省,提前添加
cbxSheng.Items.Add("江苏省");
cbxSheng.Items.Add("浙江省");
}
private void btnData_Click_1(object sender, EventArgs e)
{
FolderBrowserDialog fbd = new FolderBrowserDialog(); //打开寻找路的程序
if (fbd.ShowDialog() != DialogResult.OK)
{
return;//如果取消就终止程序,如果没有这步,程序后面获取不到路径,发生错误
}
string filePath = fbd.SelectedPath;//获取用户获取的文件夹路径
string[] files = Directory.GetFiles(filePath, "*.txt", SearchOption.AllDirectories);//将找到的".txt"格式的文件储存到前面files数组中
foreach (string file in files)//增强for循环,一边遍历数据,一边储存数据
{
string sheng = Path.GetFileNameWithoutExtension(file);//以每个文件的名字,存到"省"中
string[] lines = File.ReadAllLines(file, Encoding.Default);//逐行读取数据
foreach (string line in lines)
{
string[] str = line.Split(' ');//以' '为分隔符
string shi = str[0];//索引
string chepai = str[1];
using (SqlConnection conn = new SqlConnection("Data Source=DESKTOP-BEUJ3C4;Initial Catalog=DBCarId;User ID=sa;Password =2323010676;"))
{
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "insert into Table_CarId(省,市,车牌) values(@sheng,@shi,@chepai)";
cmd.Parameters.Add(new SqlParameter("sheng", sheng));
cmd.Parameters.Add(new SqlParameter("shi", shi));
cmd.Parameters.Add(new SqlParameter("chepai", chepai));
cmd.ExecuteNonQuery();
}
}
}
MessageBox.Show("数据加载成功!");
}
private void btnClear_Click(object sender, EventArgs e)
{
using (SqlConnection conn = new SqlConnection("Data Source=DESKTOP-BEUJ3C4;Initial Catalog=DBCarId;User ID=sa;Password =2323010676;"))
{
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "delete from Table_CarId";
cmd.ExecuteNonQuery();
MessageBox.Show("清除成功!");
}
}
private void cbxSheng_SelectedIndexChanged_1(object sender, EventArgs e)
{
cbxShi.Items.Clear();
cbxShi.Text = "";
txtChepai.Text = "";
using (SqlConnection conn = new SqlConnection ("Data Source=DESKTOP-BEUJ3C4;Initial Catalog=DBCarId;User ID=sa;Password =2323010676;"))
{
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select * from Table_CarId where 省=@sheng";
cmd.Parameters.Add(new SqlParameter("sheng", cbxSheng.Text));
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
cbxShi.Items.Add(reader.GetString(reader.GetOrdinal("市")));
}
}
}
private void btnSelect_Click_1(object sender, EventArgs e)
{
using (SqlConnection conn = new SqlConnection("Data Source=DESKTOP-BEUJ3C4;Initial Catalog=DBCarId;User ID=sa;Password =2323010676;"))
{
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select * from Table_CarId where 市=@shi";
cmd.Parameters.Add(new SqlParameter("shi", cbxShi.Text));
SqlDataReader reader = cmd.ExecuteReader();
if (reader.Read())
{
txtChepai.Text = reader.GetString(reader.GetOrdinal("车牌"));
}
}
}
}
}