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PO'UserControl' constructor with parameters in C#
 

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    <p>Call me crazy, but I'm the type of guy that likes constructors with parameters (if needed), as opposed to a constructor with no parameters followed by setting properties. My thought process: if the properties are required to actually construct the object, they should go in the constructor. I get two advantages:</p> <ol> <li>I know that when an object is constructed (without error/exception), my object is good.</li> <li>It helps avoid forgetting to set a certain property.</li> </ol> <p>This mindset is starting to hurt me in regards to form/usercontrol development. Imagine this <code>UserControl</code>:</p> <pre><code>public partial class MyUserControl : UserControl { public MyUserControl(int parm1, string parm2) { // We'll do something with the parms, I promise InitializeComponent(); } } </code></pre> <p>At designtime, if I drop this <code>UserControl</code> on a form, I get an <code>Exception</code>:</p> <blockquote> <p>Failed to create component 'MyUserControl' ...<br> System.MissingMethodException - No parameterless constructor defined for this object.</p> </blockquote> <p>It seems like, to me, the only way around that was to add the default constructor (unless someone else knows a way).</p> <pre><code>public partial class MyUserControl : UserControl { public MyUserControl() { InitializeComponent(); } public MyUserControl(int parm1, string parm2) { // We'll do something with the parms, I promise InitializeComponent(); } } </code></pre> <p>The whole point of not including the parameterless constructor was to avoid using it. And I can't even use the <code>DesignMode</code> property to do something like:</p> <pre><code>public partial class MyUserControl : UserControl { public MyUserControl() { if (this.DesignMode) { InitializeComponent(); return; } throw new Exception("Use constructor with parameters"); } } </code></pre> <p>This doesn't work either:</p> <pre><code>if (LicenseManager.UsageMode == LicenseUsageMode.Designtime) </code></pre> <p>Fine, moving along ...</p> <p>I have my parameterless constructor, I can drop it on the form, and the form's <code>InitializeComponent</code> will look like this:</p> <pre><code>private void InitializeComponent() { this.myControl1 = new MyControl(); // blah, blah } </code></pre> <p>And trust me, because I did it (yes, ignoring the comments Visual Studio generated), I tried messing around and I passed parameters to <code>InitializeComponent</code> so that I could pass them to the constructor of <code>MyControl</code>.</p> <p>Which leads me to this:</p> <pre><code>public MyForm() { InitializeComponent(); // Constructed once with no parameters // Constructed a second time, what I really want this.myControl1 = new MyControl(anInt, aString); } </code></pre> <p>For me to use a <code>UserControl</code> with parameters to the constructor, I have to add a second constructor that I don't need? And instantiate the control twice?</p> <p>I feel like I must be doing something wrong. Thoughts? Opinions? Assurance (hopefully)?</p>
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