什麼是正確的方法來添加子程序來處理C＃中的連接字符串WPF

我有一個app.config和一個完美的連接字符串。什麼是正確的方法來添加子程序來處理C＃中的連接字符串WPF

的App.config

<connectionStrings> 
    <add name="MyConnectionString" 
     connectionString="Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=myDatabaseC;Data Source=agent_edx44-PC;" 
     providerName="System.Data.SqlClient"/> 
    </connectionStrings>

我的形式

private void btnSave_Click(object sender, RoutedEventArgs e) 
{ 
    SqlConnection con = new SqlConnection(); 
    con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;   
    con.Open(); 
    SqlCommand cmd = new SqlCommand("uspINSERT",con); 
    cmd.CommandType = CommandType.StoredProcedure; 
    cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text); 
    .....some code 
} 

private void bindDataGrid() 
{ 
    SqlConnection con = new SqlConnection(); 
    con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
    con.Open(); 
    SqlCommand cmd = new SqlCommand("uspSELECTALL",con); 
    cmd.Connection = con; 
    ...some code 

}

我的問題是我想把這行代碼的子程序裏面，這樣我可以在任何方法調用它。

SqlConnection con = new SqlConnection(); 
con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;

這是我迄今所做的：

private void MyConnection() 
{ 
    SqlConnection con = new SqlConnection(); 
    con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
} 
private void btnSave_Click(object sender, RoutedEventArgs e) 
{ 
    MyConnection() 
    con.Open(); 
    SqlCommand cmd = new SqlCommand("uspINSERT",con); 
    cmd.CommandType = CommandType.StoredProcedure; 
    cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text); 
    .....some code 
}

但它有一個錯誤說：

名稱「騙子」不當前存在背景

來源

2016-12-27 Diether Silverious

你在這裏有一些不好的代碼。大多數SQL對象實現'IDisposable'，所以當你完成每個對象時，你必須使用'using'塊或調用'.Dispose（）'。 – Enigmativity

@Enigmativity你能幫我用我的代碼嗎？我是新來的c＃ –

這裏是你應該如何將這些前兩種方法寫：

private void btnSave_Click(object sender, RoutedEventArgs e) 
{ 
    using (SqlConnection con = new SqlConnection()) 
    { 
     con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
     con.Open(); 
     using (SqlCommand cmd = new SqlCommand("uspINSERT", con)) 
     { 
      cmd.CommandType = CommandType.StoredProcedure; 
      cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text); 
      //.....some code 
     } 
    } 
} 

private void bindDataGrid() 
{ 
    using (SqlConnection con = new SqlConnection()) 
    { 
     con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
     con.Open(); 
     using (SqlCommand cmd = new SqlCommand("uspSELECTALL", con)) 
     { 
      cmd.Connection = con; 
      //...some code 
     } 
    } 
}

現在，讓你的新代碼工作，你需要返回從MyConnection方法連接：

private SqlConnection MyConnection() 
{ 
    SqlConnection con = new SqlConnection(); 
    con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
    return con; 
} 

private void btnSave_Click(object sender, RoutedEventArgs e) 
{ 
    using (SqlConnection con = MyConnection()) 
    { 
     con.Open(); 
     using (SqlCommand cmd = new SqlCommand("uspINSERT", con)) 
     { 
      cmd.CommandType = CommandType.StoredProcedure; 
      cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text); 
      //.....some code 
     } 
    } 
}

現在，我會更進一步，並做到這一點：

private void RunSqlCommand(string cmdText, Action<SqlConnection, SqlCommand> execute) 
{ 
    using (SqlConnection con = new SqlConnection()) 
    { 
     con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
     con.Open(); 
     using (SqlCommand cmd = new SqlCommand(cmdText, con)) 
     { 
      cmd.Connection = con; 
      execute(con, cmd); 
     } 
    } 
}

現在你的btnSave_Click方法可以變成這樣：

private void btnSave_Click(object sender, RoutedEventArgs e) 
{ 
    RunSqlCommand("uspINSERT", (con, cmd) => 
    { 
     cmd.CommandType = CommandType.StoredProcedure; 
     cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text); 
     //.....some code 
    }); 
}

來源

2016-12-27 03:51:46 Enigmativity

謝謝隊友。它像一個魅力。我很高興現在學習新的東西:-) –

更改您的MyConnection會見HOD這一點，它返回一個SqlConnection：

private SqlConnection MyConnection() 
{ 
    SqlConnection con = new SqlConnection(); 
    con.ConnectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
    return con; 
}

這是如何使用：

using (var con = MyConnection()) 
{ 
    //your code 
}

using塊將處置您的數據庫連接你用它做了。

來源

2016-12-27 03:39:51

什麼是正確的方法來添加子程序來處理C＃中的連接字符串WPF

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