C＃ - 本地数据库连接字符串的格式（.sdf文件） [英] C# - formatting of local database connection string (.sdf file)

问题描述

我可以直接使用我的winform应用程序连接到我的本地db文件.sdf。但是当我使用connstring时无法这样做。这就是我的尝试



1。使用app.config文件

i am able to connect to my local db file .sdf directly with my winform app. but unable to do so when i am using an connstring. here is what i have tried

1. using app.config file

var config =  ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            var connectionStringsSection = (ConnectionStringsSection)config.GetSection("connectionStrings");
            connectionStringsSection.ConnectionStrings["DEVID"].ConnectionString = textBox6.Text;
            config.Save();
            ConfigurationManager.RefreshSection("connectionStrings");
            SqlCeConnection con = new SqlCeConnection();
            string DEVID = ConfigurationManager.ConnectionStrings["DEVID"].ConnectionString;
            con.ConnectionString = DEVID; // getting error as "object reference not set"
//SqlCeConnection con = new SqlCeConnection(DEVID); // in my app.config file i set my connection string = "Data Source=C:\Users\john\Documents\Visual Studio 2010\Projects\AECCS\AECCS\Database1.sdf

2.使用直接字符串变量

2. using direct string variable

//SqlCeConnection con = new SqlCeConnection(@"Data Source=C:\Users\john\Documents\Visual Studio 2010\Projects\AECCS\AECCS\Database1.sdf"); // this is the actual conn string value
            string connstring1 = "\"Data Source=" + textBox6.Text + "\"";
            string connstring2 = "@"+connstring1;
            textBox2.Text = connstring2; // matches exactly with my actual connection string, but still not getting to connect with .sdf file
SqlCeConnection con = new SqlCeConnection(connstring2); // getting error as format of initialization string does not conform at index 0""

请帮我解决问题



我尝试过：



// SqlCeConnection con = new SqlCeConnection（@Data Source = C：\ Users\john\Documents\Visual Studio 2010 \\ \\Projects\AECCS\AECCS\Database1.sdf）; //这是实际的conn字符串值

string connstring1 =\Data Source =+ textBox6.Text +\;

string connstring2 = @+ connstring1;

textBox2.Text = connstring2; //与我的实际连接字符串完全匹配，但仍然无法连接.sdf文件

SqlCeConnection con = new SqlCeConnection（connstring2）; //因为初始化字符串的格式不符合索引0而得到错误

please help me out to solve the issue

What I have tried:

//SqlCeConnection con = new SqlCeConnection(@"Data Source=C:\Users\john\Documents\Visual Studio 2010\Projects\AECCS\AECCS\Database1.sdf"); // this is the actual conn string value
string connstring1 = "\"Data Source=" + textBox6.Text + "\"";
string connstring2 = "@"+connstring1;
textBox2.Text = connstring2; // matches exactly with my actual connection string, but still not getting to connect with .sdf file
SqlCeConnection con = new SqlCeConnection(connstring2); // getting error as "format of initialization string does not conform at index 0"

推荐答案

你前面不需要@，所以请保留钻了出来。 @不是字符串的一部分，它是编译器将所有字符视为文字的指令。它在处理路径时使用，因此您不必转义\字符。

You don't need the "@" at the front, so leave that bit out. The @ isn't part of the string, it is an instruction to the compiler to treat all characters as literal. It is used when dealing with paths so you don't have to escape the "\" characters.

SqlCeConnection con = new SqlCeConnection(connstring1);

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