/**
* 获取启动图片
*/
+(UIImage *)launchImage{
NSString *imageName=@"LaunchImage-700";
if(iphone5x_4_0) imageName=@"LaunchImage-700-568h";
if(iphone6_4_7) imageName = @"LaunchImage-800-667h";
if(iphone6Plus_5_5) imageName = @"LaunchImage-800-Portrait-736h";
UIImage *image = [UIImage imageNamed:imageName];
NSAssert(image != nil, @"Charlin Feng提示您:请添加启动图片!");
return image;
}