iphone - 在图像上显示叠加层

Question

使用本教程:http://www.techotopia.com/index.php/An_Example_iOS_4_iPhone_Camera_Application_%28Xcode_4%29我在 UI 上显示了照片库中的图像。我想简单地在 UIImage 上覆盖一些基本文本或形状(如正方形)。有没有简单的方法可以做到这一点？

谢谢。

Answer 1

您只有 UIImage 还是使用 UIImageView 显示它？

如果你有一个 UIImageView 那么你可以添加一个 UILabel 作为你的 ImageView 的 subview 。

假设你的 UIImageView 被命名为 myImageView ...

// Create and init the label with any rect. 
UILabel *myLabel = [[UILabel alloc] initWithFrame:myImageView.frame]; // The lable has the same size as the Image has.
mylabel.text = @"the text";
[myImageView addSubview:myLabel];
//A subview's coordinates are within its superview's coordinates. 
mylabel.center = CGPointMake(myImageView.frame.size.width/2,myImageView.frame.size.height/2) // aligning the centers of the views
//An alternative could be transforming the image's center into the coordinate system of its superviews. That code would look smarter but his example is imho easier to understand.

//Setting front, size, alpha, background colour ... 
...