2019-03-22

iOSのコード実装イメージサイズsizeの変更

UIImageのCategoryメソッド:

//     image 
/*
      ：UIImage   
    size：        size
*/
-(UIImage*)scaleToSize:(CGSize)size
{
    //     bitmap context
    //               context
    //Determine whether the screen is retina
    if([[UIScreen mainScreen] scale] == 2.0)
    {
        UIGraphicsBeginImageContextWithOptions(size, NO, 2.0);
    }else{
        UIGraphicsBeginImageContext(size);
    }
    //          
    [self drawInRect:CGRectMake(0, 0, size.width, size.height)];
    //    context             
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    //     context   
    UIGraphicsEndImageContext();
    //             
    return scaledImage;
}

随所に配置可能なオブジェクトメソッド:

//     image
/*
      ：UIImage   
    size：        size
    image：        image
*/
-(UIImage*)scaleToSize:(CGSize)size image:(UIImage*)image
{
    //     bitmap context
    //               context
    //Determine whether the screen is retina
    if([[UIScreen mainScreen] scale] == 2.0)
    {
        UIGraphicsBeginImageContextWithOptions(size, NO, 2.0);
    }else{
        UIGraphicsBeginImageContext(size);
    }
    //          
    [image drawInRect:CGRectMake(0, 0, size.width, size.height)];
    //    context             
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    //     context   
    UIGraphicsEndImageContext();
    //             
    return scaledImage;
}