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POTrouble adding text to a UIImageView using DrawString (MonoTouch)
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  1. POTrouble adding text to a UIImageView using DrawString (MonoTouch)
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    copied!<p><br> I want to write text on to an image on an iPhone, using C# and MonoTouch. The DrawImage method seems pretty straight forward, but I get errors when I run it. What am I missing? Any help is greatly appreciated!<br> Thanks in advance. </p> <p>The errors:</p> <pre><code>Thu Feb 3 12:40:34 MacMini.local ImageTextMT[3877] &lt;Error&gt;: CGContextSetFont: invalid context 0x0 Thu Feb 3 12:40:34 MacMini.local ImageTextMT[3877] &lt;Error&gt;: CGContextSetTextMatrix: invalid context 0x0 Thu Feb 3 12:40:34 MacMini.local ImageTextMT[3877] &lt;Error&gt;: CGContextSetFontSize: invalid context 0x0 Thu Feb 3 12:40:34 MacMini.local ImageTextMT[3877] &lt;Error&gt;: CGContextSetTextPosition: invalid context 0x0 Thu Feb 3 12:40:34 MacMini.local ImageTextMT[3877] &lt;Error&gt;: CGContextShowGlyphsWithAdvances: invalid context 0x0 </code></pre> <p>MonoDevelop 2.4.2, MonoTouch </p> <ol> <li><p>I created a New Solution: C#, iPhone and iPad, iPhone Window-based Project</p></li> <li><p>Editted the MainWindow.xib:<br> 2a. Added UIImageView and UIButton to the Window;<br> 2b. To the AppDelegate I added two outlets, btnAddText (referenced to the UIButton) and imgImage (referenced to the UIImageView); </p></li> <li><p>Code (sorry-- code-formatting challenged...):</p> <pre><code>using System; using System.Collections.Generic; using MonoTouch.Foundation; using MonoTouch.UIKit; using MonoTouch.CoreGraphics; using System.Drawing; namespace ImageTextMT; { public class Application { static void Main (string[] args) { UIApplication.Main (args); } } // The name AppDelegate is referenced in the MainWindow.xib file. public partial class AppDelegate : UIApplicationDelegate { // This method is invoked when the application has loaded its UI and its ready to run public override bool FinishedLaunching (UIApplication app, NSDictionary options) { // If you have defined a view, add it here: // window.AddSubview (navigationController.View); window.MakeKeyAndVisible (); // Add the events for the controls btnAddText.TouchDown += btnAddText_Click; imgImage.Image = UIImage.FromFile("/Users/ParisRat/Projects/ImageTextMT/ImageTextMT/images/testblock.png"); return true; } protected void btnAddText_Click (object sender, EventArgs e) { // Define a rectangle System.Drawing.RectangleF rect = new System.Drawing.RectangleF(10.0f, 5.0f, 20.0f, 25.0f); // *** Write text on to the image *** this.imgImage.DrawString("HELLO",rect,UIFont.SystemFontOfSize(15.0f), UILineBreakMode.CharacterWrap, UITextAlignment.Left); } // This method is required in iPhoneOS 3.0 public override void OnActivated (UIApplication application) { } } } </code></pre></li> </ol>
 

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