获取App启动图的方法

CGSize viewSize = self.window.bounds.size;
NSString *viewOrientation = @"Portrait";    //横屏请设置成 @"Landscape"
NSString *launchImage = nil;

NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary* dict in imagesDict)
{
    CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
    
    if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
    {
        launchImage = dict[@"UILaunchImageName"];
    }
}

为启动图添加一个动画效果

UIImageView *launchView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:launchImage]];
launchView.frame = self.window.bounds;
launchView.contentMode = UIViewContentModeScaleAspectFill;
[self.window addSubview:launchView];

[UIView animateWithDuration:2.0f
                      delay:0.0f
                    options:UIViewAnimationOptionBeginFromCurrentState
                 animations:^{
                     
                     launchView.alpha = 0.0f;
                     launchView.layer.transform = CATransform3DScale(CATransform3DIdentity, 1.2, 1.2, 1);
                     
                 }
                 completion:^(BOOL finished) {
                     
                     [launchView removeFromSuperview];
                     
                 }];

NSString转NSData

- (NSData *)convertHexStrToData:(NSString *)str {
    if (!str || [str length] == 0) {
        return nil;
    }
    
    NSMutableData *hexData = [[NSMutableData alloc] initWithCapacity:8];
    NSRange range;
    if ([str length] % 2 == 0) {
        range = NSMakeRange(0, 2);
    } else {
        range = NSMakeRange(0, 1);
    }
    for (NSInteger i = range.location; i < [str length]; i += 2) {
        unsigned int anInt;
        NSString *hexCharStr = [str substringWithRange:range];
        NSScanner *scanner = [[NSScanner alloc] initWithString:hexCharStr];
        
        [scanner scanHexInt:&anInt];
        NSData *entity = [[NSData alloc] initWithBytes:&anInt length:1];
        [hexData appendData:entity];
        
        range.location += range.length;
        range.length = 2;
    }
    return hexData;
}

NSData转NSString

- (NSString *)convertDataToHexStr:(NSData *)data {
    if (!data || [data length] == 0) {
        return @"";
    }
    NSMutableString *string = [[NSMutableString alloc] initWithCapacity:[data length]];
    
    [data enumerateByteRangesUsingBlock:^(const void *bytes, NSRange byteRange, BOOL *stop) {
        unsigned char *dataBytes = (unsigned char*)bytes;
        for (NSInteger i = 0; i < byteRange.length; i++) {
            NSString *hexStr = [NSString stringWithFormat:@"%x", (dataBytes[i]) & 0xff];
            if ([hexStr length] == 2) {
                [string appendString:hexStr];
            } else {
                [string appendFormat:@"0%@", hexStr];
            }
        }
    }];
    
    return string;
}