Transparent UIImage

Question

I am creating an iOS application in which I have added a simple UIImage. I want to add the transparency effect in image to show other images behind that main image. Tell me how I can achieve this effect?

Note: I don't want to change the opacity/alpha of image.

Answer 1

An alpha change is how you alter transparency. In addition to this, you would want to alter this on the view level not on to the UIImage directly. Ex:

[myImageView setImage:[UIImage imageNamed@"myImage.png"]];
[myImageView setAlpha:0.7f];

Answer 2

使用其中带有Alpha通道的png格式的图像：Alpha通道是告诉每个像素多少透明的层

Answer 3

how about this:

self.imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0.0f,0.0f,1024.0f,768.0f)];
self.imageView.backgroundColor = [UIColor colorWithRed:255 green:255 blue:255 alpha:0.5];
[self.view addSubview:self.imageView];

or set its alpha
imageView.alpha = 0.5;

But be sure to instantiate the imageView, as property then synthesize.