图片拉伸 iOS

创建category文件

.h

#import <UIKit/UIKit.h>

@interface UIImage (ImageScale)

-(UIImage *)imageScaleSize:(CGSize)size;

@end

.m

#import "UIImage+ImageScale.h"

@implementation UIImage (ImageScale)

-(UIImage *)imageScaleSize:(CGSize)size{

    UIGraphicsBeginImageContext(size);

    [self drawInRect:CGRectMake(0, 0, size.width, size.height)];

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    

    UIGraphicsEndImageContext();

    return image;

}

@end

在ViewController中

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    

    [self imageScale];

    

}

-(void)imageScale{

    UIImage *image =[UIImage imageNamed:@"1"];

    UIImage *imageNew =[image imageScaleSize:CGSizeMake(200, 500)];

    UIImageWriteToSavedPhotosAlbum(imageNew, nil, nil, nil); // 将图片保存到手机相册中

}

添加 <key>NSPhotoLibraryUsageDescription</key> <string>App需要您的同意,才能访问相册</string> 

iOS 10如果访问必须添加否则闪退