【代碼筆記】多張圖片合成一張

代碼：

RootViewController.m

#import "RootViewController.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    NSArray *imgArray = [[NSArray alloc] initWithObjects:
                         [UIImage imageNamed:@"1.jpg"],
                         [UIImage imageNamed:@"2.jpg"],
                         [UIImage imageNamed:@"3.jpg"],
                         [UIImage imageNamed:@"4.jpg"],
                         [UIImage imageNamed:@"5.jpg"],
                        nil];
    
    NSArray *imgPointArray = [[NSArray alloc] initWithObjects:
                              @"10", @"10",
                              @"10", @"25",
                              @"30", @"15",
                              @"30", @"50",
                              @"20", @"80",
                              nil];
    
    
    BOOL suc = [self mergedImageOnMainImage:[UIImage imageNamed:@"1.jpg"] WithImageArray:imgArray AndImagePointArray:imgPointArray];
    
    if (suc == YES) { 
        NSLog(@"Images Successfully Mearged & Saved to Album"); 
    } 
    else { 
        NSLog(@"Images not Mearged & not Saved to Album"); 
    }
    
}
#pragma -mark -functions
//多張圖片合成一張
- (BOOL) mergedImageOnMainImage:(UIImage *)mainImg WithImageArray:(NSArray *)imgArray AndImagePointArray:(NSArray *)imgPointArray
{
    
    UIGraphicsBeginImageContext(mainImg.size);
    
    [mainImg drawInRect:CGRectMake(0, 0, mainImg.size.width, mainImg.size.height)];
    int i = 0;
    for (UIImage *img in imgArray) {
        [img drawInRect:CGRectMake([[imgPointArray objectAtIndex:i] floatValue],
                                   [[imgPointArray objectAtIndex:i+1] floatValue],
                                   img.size.width,
                                   img.size.height)];
        
        i+=2;
    }
    
    CGImageRef NewMergeImg = CGImageCreateWithImageInRect(UIGraphicsGetImageFromCurrentImageContext().CGImage,
                                                          CGRectMake(0, 0, mainImg.size.width, mainImg.size.height));
    
    UIGraphicsEndImageContext();
    if (NewMergeImg == nil) {
        return NO;
    }
    else {
        UIImageWriteToSavedPhotosAlbum([UIImage imageWithCGImage:NewMergeImg], self, nil, nil);
        return YES;
    }
}



- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end