blocks|key|1956904|text|使用ConfigurationManager而不是ConfigurationSettings。它有一个ConnectionStrings属性，您应该将该属性用于connectionStrings部分中的连接字符串：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1956905|ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString;|code-block|syntax|javascript|1956906|entityMap^0|2|K|P|L|1F|H|28|H|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|L|$]]

Use <code>ConfigurationManager</code> instead of <code>ConfigurationSettings</code>. It has a <code>ConnectionStrings</code> property that you should use for connection strings in the <code>connectionStrings</code> section:

<pre><code>ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString;
</code></pre>

blocks|key|1743606|text|您使用的是ConnectionStrings集合，而不是AppSettings。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1743607|ConfigurationManager.ConnectionStrings["MyDbConnectionString"].ConnectionString;|code-block|syntax|javascript|1743608|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You are using the ConnectionStrings collection, not the AppSettings.

<pre><code>ConfigurationManager.ConnectionStrings["MyDbConnectionString"].ConnectionString;
</code></pre>

blocks|key|1956945|text|尝尝这个|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1956946|+ConfigurationManager.ConnectionStrings["MyDbConnectionString"].ConnectionString;+|code-block|syntax|javascript|1956947|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

try this

<pre><code> ConfigurationManager.ConnectionStrings["MyDbConnectionString"].ConnectionString; 
</code></pre>

blocks|key|1743617|text|这就是你所需要的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1743618|System.Configuration.ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString;|code-block|syntax|javascript|1743619|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is all you need:

<pre><code>System.Configuration.ConfigurationManager.ConnectionStrings["MyDBConnectionString"].ConnectionString;
</code></pre>

blocks|key|1956973|text|using+(SqlConnection+conn+=+new+SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["SQLConnection"].ToString()))
{
....(your+code+here)+...
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1956974|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["SQLConnection"].ToString()))
{
....(your code here) ...
}
</code></pre>

blocks|key|1743656|text|<?xml+version="1.0"+encoding="utf-8"+?>
<configuration>

<appSettings>

<add+key="ConnectionString"+value="Data+Source=MY-PC;Initial+Catalog=DB2013;User+ID=sa;Password=MYSQL123"+/>

</appSettings>

</configuration>
using+System.Configuration;
using+System.Data.SqlClient;

namespace+OnlineDelete_W2013
{
public+partial+class+CommodityEdit+:+Form
{
+++SqlConnection+MyConnection+=+new+SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"]);

++++public+CommodityEdit()
++++{
++++++++InitializeComponent();

++++}

++++private+void+button1_Click(object+sender,+EventArgs+e)
++++{
++++++++try
++++++++{
+++++++++++MyConnection.Open();
++++++++}
++++++++catch+(Exception)
++++++++{

++++++++++++throw;
++++++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1743657|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;
&lt;configuration&gt;

&lt;appSettings&gt;

&lt;add key="ConnectionString" value="Data Source=MY-PC;Initial Catalog=DB2013;User ID=sa;Password=MYSQL123" /&gt;

&lt;/appSettings&gt;

&lt;/configuration&gt;
using System.Configuration;
using System.Data.SqlClient;

namespace OnlineDelete_W2013
{
public partial class CommodityEdit : Form
{
 SqlConnection MyConnection = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"]);

 public CommodityEdit()
 {
 InitializeComponent();

 }

 private void button1_Click(object sender, EventArgs e)
 {
 try
 {
 MyConnection.Open();
 }
 catch (Exception)
 {

 throw;
 }
</code></pre>

blocks|key|1743681|text|SqlConnection+conn+=+new+SqlConnection();
conn.ConnectionString+=+ConfigurationManager
++++.ConnectionStrings["MyDBConnectionString"].ConnectionString;
try
{
++++conn.Open();++++++++++++++++
}
catch+(Exception)
{
++++throw;++++++++++++++++++++
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1743682|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>SqlConnection conn = new SqlConnection();
conn.ConnectionString = ConfigurationManager
 .ConnectionStrings["MyDBConnectionString"].ConnectionString;
try
{
 conn.Open(); 
}
catch (Exception)
{
 throw; 
}
</code></pre>

blocks|key|1957097|text|请尝试以下代码。这是您所期望的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1957098|SqlConnection+MyConnection+=+new+SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);+++++++|code-block|syntax|javascript|1957099|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Please try below code. this is as you are expecting:

<pre><code>SqlConnection MyConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString); 
</code></pre>

I can't seem to be able to access the app.config database connection string in my c# winforms app. 

app.config code

<pre><code> &lt;connectionStrings&gt;
 &lt;add name="MyDBConnectionString" providerName="System.Data.SqlClient"
 connectionString="Data Source=localhost;Initial Catalog=MySQLServerDB; Integrated Security=true" /&gt;
 &lt;/connectionStrings&gt; 
</code></pre>

C# code: 

<pre><code>SqlConnection conn = new SqlConnection();
conn.ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["MyDBConnectionString"]; 
</code></pre>

When I try the C# code, I get a message: 
Warning 1 'System.Configuration.ConfigurationSettings.AppSettings' is obsolete: '
This method is obsolete, it has been replaced by System.Configuration!System.Configuration.ConfigurationManager.AppSettings'

However, when I try to use: 

<pre><code>conn.ConnectionString = System.Configuration!System.Configuration.ConfigurationManager.AppSettings["MyDBConnectionString"]; 
</code></pre>

I get an error: Only assignment, call, increment, decrement, and new object expressions can be used as a statement

Accessing database connection string using app.config in C# winform

数据库

我似乎无法访问我的c# winforms应用程序中的app.config数据库连接字符串。app.config代码 <connectionStrings> <add name="MyDBConnectionString" providerName="System.Data.SqlClient" ...

问在C# winform中使用app.config访问数据库连接字符串
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