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POC# Dynamic return type
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  1. POC# Dynamic return type
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    copied!<h3>I've solved my problem</h3> <pre><code> public virtual T GenerateCommand() { Type typeParameterType = typeof(T); if (typeParameterType == typeof(SqlCommand)) { //SqlCommand } else if (typeParameterType == typeof(MySqlCommand)) { //MySqlCommand } return new T() { }; } </code></pre> <p>I'm building a class that generates Queries/Commands, the class has the ability to generate various DbCommands (MsSqlServer &amp; MySql) when the type of the database is defined in field of the class. How can I return the correct type?</p> <p>I tried this:</p> <pre><code>public virtual DbCommand GenerateCommand() { //..... } </code></pre> <p>but I always need to convert the return value:</p> <pre><code>MySqlCommand s = this.GenerateCommand() as MySqlCommand; </code></pre> <p>I also tried this:</p> <pre><code>public virtual T GenerateCommand&lt;T&gt;() { //..... } </code></pre> <p>But it's not what I'm looking for because I cannot create an instance of DbCommand so I cannot return nothing.</p> <p>Is there some way that T will be based on stored type on my class?</p> <p>Edit: the using of generic class throw two exceptions at least:</p> <pre><code> if (T is MySqlCommand) { return new MySqlCommand(); } else { return new SqlCommand(); } </code></pre> <blockquote> <p>'T' is a 'type parameter' but is used like a 'variable'</p> <p>Cannot implicitly convert type 'MySql.Data.MySqlClient.MySqlCommand' to 'T'</p> </blockquote> <pre><code>(T)MySqlCommand() </code></pre> <p>also do not work</p> <p>Edit 2: can I do something like that?</p> <pre><code>public virtual T GenerateCommand(SqlDatabaseKind dbKind) { T = (dbKind == SqlDatabaseKind.MicrosoftSqlServer) ? SqlCommand : MySqlCommand; } </code></pre>
 

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