要实现的功能效果图如下：因为我们要测试数据是从输入框获得的，所以，我们的连接字符串不是写死在应用程序中的。下面我就详细介绍一下。
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" alt=""> 
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" alt="">
首先，我们要找到 项目下——》Properties->Setiings.setting
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" alt="">
新建一个连接字符串名称，类型为 string，重点重点 范围一定要设置为 用户，这样的话我们才可以重写base.在继承的基础上覆盖上次的连接字符串。 如果我们不设置为用户而设置为应用程序获的话，将会不可改变连接字符串。
在EF框架中，我们每new一个 DataContext便会有一个数据库表的映射。它的逻辑是，我们new的时候（此例子 datacontext是 ）会执行
Console.WriteLine(</span><span style="color: #0000ff;">global</span><span style="color: #000000;">::DataModal.Properties.Settings.Default.StockManageSystemConnectionString);
OnCreated();
}
</span><span style="color: #0000ff;">public</span> StockManageDataContext(<span style="color: #0000ff;">string</span><span style="color: #000000;"> connection) :
</span><span style="color: #0000ff;">base</span><span style="color: #000000;">(connection,mappingSource)
{
OnCreated();
}
</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> StockManageDataContext(System.Data.IDbConnection connection) :
</span><span style="color: #0000ff;">base</span><span style="color: #000000;">(connection,mappingSource)
{
OnCreated();
}
</span><span style="color: #0000ff;">public</span> StockManageDataContext(<span style="color: #0000ff;">string</span><span style="color: #000000;"> connection,System.Data.Linq.Mapping.MappingSource mappingSource) :
</span><span style="color: #0000ff;">base</span><span style="color: #000000;">(connection,mappingSource)
{
OnCreated();
}
</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> StockManageDataContext(System.Data.IDbConnection connection,mappingSource)
{
OnCreated();
}</span></pre>
这个代码中就是可以覆盖的连接字符串，我们只需要更改他就行。
代码来了来了
</span><span style="color: #008000;">//</span><span style="color: #008000;">获得连接字符串</span>
<span style="color: #0000ff;">string</span> ConnectionString = <span style="color: #800000;">"</span><span style="color: #800000;">Data Source=</span><span style="color: #800000;">"</span> + Server.Text + <span style="color: #800000;">"</span><span style="color: #800000;">;Initial Catalog=</span><span style="color: #800000;">"</span> + <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>name.Text + <span style="color: #800000;">"</span><span style="color: #800000;">;Persist Security Info=True;User ID=</span><span style="color: #800000;">"</span> + Account.Text + <span style="color: #800000;">"</span><span style="color: #800000;">;Password=</span><span style="color: #800000;">"</span> +<span style="color: #000000;"> Pass.Text;
<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Connection _<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Connection </span>= <span style="color: #0000ff;">new</span><span style="color: #000000;"> <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Connection(ConnectionString);
</span><span style="color: #0000ff;">try</span><span style="color: #000000;">
{
_<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Connection.Open();
<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Command <a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>cmd </span>=<span style="color: #000000;"> _<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Connection.CreateCommand();
<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>cmd.CommandText </span>= <span style="color: #800000;">"</span><span style="color: #800000;">select top 10 * from ProductInfo;</span><span style="color: #800000;">"</span><span style="color: #000000;">;
</span><span style="color: #008000;">//</span><span style="color: #008000;">如果可以连接成功则 保存<a href="https://www.jb51.cc/tag/shujuku/" target="_blank" class="keywords">数据库</a>连接字符串 </span>
DataModal.Properties.Settings.Default.StockManageSystemConnectionString =<span style="color: #000000;"> ConnectionString;
DataModal.Properties.Settings.Default.Save();</span><span style="color: #008000;">//</span><span style="color: #008000;">使用Save<a href="https://www.jb51.cc/tag/fangfa/" target="_blank" class="keywords">方法</a>保存更改 n</span>
Message<a href="https://www.jb51.cc/tag/Box/" target="_blank" class="keywords">Box</a>.Show(<span style="color: #800000;">"</span><span style="color: #800000;">测试连接正常</span><span style="color: #800000;">"</span>,<span style="color: #800000;">"</span><span style="color: #800000;">恭喜</span><span style="color: #800000;">"</span><span style="color: #000000;">);
</span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">true</span><span style="color: #000000;">;
}
</span><span style="color: #0000ff;">catch</span><span style="color: #000000;"> (Exception ex)
{
Message<a href="https://www.jb51.cc/tag/Box/" target="_blank" class="keywords">Box</a>.Show(</span><span style="color: #800000;">"</span><span style="color: #800000;">不能连接<a href="https://www.jb51.cc/tag/shujuku/" target="_blank" class="keywords">数据库</a>，请重新设置</span><span style="color: #800000;">"</span>,<span style="color: #800000;">"</span><span style="color: #800000;">警告</span><span style="color: #800000;">"</span><span style="color: #000000;">);
</span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">false</span><span style="color: #000000;">;
}
</span><span style="color: #0000ff;">finally</span><span style="color: #000000;">
{
_<a href="https://www.jb51.cc/tag/sql/" target="_blank" class="keywords">sql</a>Connection.Close();
}
}</span></pre>
这样就可以进行测试了，在每次登陆之前都要验证一遍。
还有一个比较人性化的问题，就是用户希望在每次登陆之前都有几个数据库连接默认的值，毕竟大家不愿意去动手输入那么多数据，但是又不可以直接写死在输入框（这样太low）,所以，既然之前我们可以给连接字符串赋值，我们也可以获取上次的连接字符串，拆分，然后在窗体初始化时默认加载到窗体输入框嘛。
代码：（根据键值对获得，）
原文链接：https://www.f2er.com/aspnet/238740.html
