尝试重叠两个图像，并在第三个图像中显示重叠图像

Question

我想重叠两个本地图像，并尝试在第三个图像中显示重叠的图像。 我正在使用此代码，但模拟器什么也没有显示。

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    image1 = [[UIImage alloc]init]; 

    image1 = [UIImage imageNamed:@"iphone.png"]; 

    imageA = [[UIImageView alloc]initWithImage:image1]; 


    [self merge]; 

} 

-(void)merge 
{ 
    CGSize size = CGSizeMake(320, 480); 
    UIGraphicsBeginImageContext(size); 

    CGPoint thumbPoint = CGPointMake(0,0); 
    imageview.image = imageA.image; 
    [imageA.image drawAtPoint:thumbPoint]; 

    imageB = [[UIImage alloc]init]; 

    imageB = [UIImage imageNamed:@"Favorites.png"]; 

    CGPoint starredPoint = CGPointMake(0, 0); 
    [imageB drawAtPoint:starredPoint]; 

    UIImage *imageC = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 
    imageview.image = imageC; 

    [self.view addSubview:imageview]; 

} 

我找不出/不知道我在哪里犯错。

任何帮助将是可观的。

Answer 1

从每一个地方除了在合并下面的代码删除所有的代码。

-(void)merge 
{ 
    CGSize size = CGSizeMake(320, 480); 
    UIGraphicsBeginImageContext(size); 

    CGPoint point1 = CGPointMake(0,0); 
    // The second point has to be some where different than the first point, other wise, the second image will be above the first image, and you wont even know that the two images are there. 
    CGPoint point2 = CGPointMake(100,100); 

    UIImage *imageOne = [UIImage imageNamed:@"Image1.png"]; 
    [imageOne drawAtPoint:point1]; 



    UIImage *imageTwo = [UIImage imageNamed:@"Image2.png"]; 
    // If you want the above image to have some blending, then you can do some thing like below. 
    // [imageTwo drawAtPoint:point2 blendMode:kCGBlendModeMultiply alpha:0.5]; 

    [imageTwo drawAtPoint:point2]; 


    UIImage *imageC = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 

    UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(100,100,200,200)]; 
    iv.image=imageC; 

    [self.view addSubview:iv]; 


} 

Answer 2

这里有一个通用的“合并”功能写为一个UIImage类别...允许图像覆盖/底层。

http://saveme-dot-txt.blogspot.com/2011/06/merge-image-function.html