當前位置：首頁 > 人文社科 > 生活经验 >内容正文

生活经验

C# 异步读取数据库里面的数据与绑定UI的解决办法

發布時間：2023/11/27 生活经验 23 豆豆

生活随笔收集整理的這篇文章主要介紹了 C# 异步读取数据库里面的数据与绑定UI的解决办法小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

異步讀取數據庫,在數據綁定的時候會出現點問題,就是窗體界面會無法關閉,要結束任務才能結束進程。例如下面代碼

首先按習慣的方法，設定線程更新UI

a2.CheckForIllegalCrossThreadCalls = false;?? //a2為窗體名稱

下面的代碼就是從數據庫里取得數據并綁定

private void button1_Click(object sender, EventArgs e)
??????? {
??????????? SqlConnection con;
??????????? SqlCommand com;
??????????? try
??????????? {
??????????????? con = new SqlConnection("UID=sa;Password=123;Initial Catalog=AD;Data Source=192.168.1.1;Asynchronous Processing=true");
??????????????? con.Open();
??????????????? com = new SqlCommand("select top 100 * from tb_user", con);
??????????????? com.BeginExecuteReader(new AsyncCallback(delDataBin), com);
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? MessageBox.Show("程序發生錯誤,信息: " + ex.Message);
??????????? }

??????? }

??????? private void delDataBin(IAsyncResult ar)
??????? {
??????????? if (ar.IsCompleted)
??????????? {
??????????????? SqlCommand com = (SqlCommand)ar.AsyncState;
??????????????? SqlDataReader dr = com.EndExecuteReader(ar);
??????????????? DataTable dt = new DataTable();
??????????????? dt.Load(dr);
??????????????? dr.Close();

??????????????? this.dataGridView1.DataSource = dt;?? //綁定數據????????????

??????????? }
??????? }

到這里完成的綁定的工作，運行查看一下效果，其實這樣是會出現窗體假死的現象。

下面通過Invoke 來實現

首先聲明委托? public delegate void updateDG(DataTable dt);

然后通過dataBin來綁定DataGridView

??????? public void dataBin(DataTable dt)
??????? {
??????????? dataGridView1.DataSource = dt;
??????????? return;
??????? }?

在線程里面調用下面方法

//綁定數據
??????????????? if (this.InvokeRequired)
??????????????? {
??????????????????? updateDG ur = new updateDG(dataBin);
??????????????????? this.Invoke(ur, dt);
??????????????? }

完整的代碼如下:

??????? private void button1_Click(object sender, EventArgs e)
??????? {
??????????? SqlConnection con;
??????????? SqlCommand com;
??????????? try
??????????? {
??????????????? con = new SqlConnection("UID=sa;Password=123;Initial Catalog=AD;Data Source=192.168.1.1;Asynchronous Processing=true");
??????????????? con.Open();
??????????????? com = new SqlCommand("select top 100 * from tb_user", con);
??????????????? com.BeginExecuteReader(new AsyncCallback(delDataBin), com);
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? MessageBox.Show("程序發生錯誤,信息: " + ex.Message);
??????????? }

??????? }

??????????????? //this.dataGridView1.DataSource = dt;//綁定數據

????????????????if (this.InvokeRequired)
??????????????? {
??????????????????? updateDG ur = new updateDG(dataBin);
??????????????????? this.Invoke(ur, dt);
??????????????? }
??????????? }
??????? }
???????
??????? public delegate void updateDG(DataTable dt);

??????? public void dataBin(DataTable dt)
??????? {
??????????? dataGridView1.DataSource = dt;
??????????? return;
??????? }???????????

查運行查看一下，你就會發現結果了

轉載于:https://www.cnblogs.com/whtydn/archive/2009/07/07/1518209.html

總結

以上是生活随笔為你收集整理的C# 异步读取数据库里面的数据与绑定UI的解决办法的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。