Question

我拍摄了我窗口某个部分的屏幕截图，然后将其缩小并与缩小的图像合并。问题是，当我走到它的路径时，有一个保存为0KB的PNG文件，因此图像不会被保存。任何的想法？谢谢！

这是我目前的代码：

//Save images
- (void) saveimages {

    //Save small one (mini)
    NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    UIGraphicsBeginImageContextWithOptions((myImageView.bounds.size), NO, 0.5);
    [myImageView.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *mini = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    float miniVW = VView.image.size.width / 2;
    float miniVH = VView.image.size.height / 2;
    UIImage *miniV = [self imageWithImage:certain.image convertToSize:CGSizeMake(miniVW, miniVH)];
    UIImage *miniTotal = [self mergeIMG:miniV:mini];
    NSString *pngFilePath = [NSString stringWithFormat:@"%@/mini%i.png",docDir,number];
    NSData *data = [NSData dataWithData:UIImagePNGRepresentation(miniTotal)];
    [data writeToFile:pngFilePath atomically:YES];

}

//Merge two images in one
- (UIImage *) mergeIMG:(UIImage *)VextImg:(UIImage *)VintImg {

    //Create a new image from two
    CGSize newSize = CGSizeMake(VintImg.size.width, VintImg.size.width);
    [VintImg drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
    [VextImg drawInRect:CGRectMake(0, 0, newSize.width, newSize.height) blendMode:kCGBlendModeNormal alpha:1.0];
    UIImage *finalIMG = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return finalIMG;
}

//Scale image
- (UIImage *) imageWithImage:(UIImage *)image convertToSize:(CGSize)size {

    //Change size
    UIGraphicsBeginImageContext(size);
    [image drawInRect:CGRectMake(0, 0, size.width, size.height)];
    UIImage *destImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return destImage;

}

Answer 1

mergeImage不会致电UIGraphicsBeginImageContextWithOptions

缩放和合并的图像无法正常保存（iOS）

1 个答案: