判断源分辨率是否属于指定宽高比

Question

我想确定一个源分辨率是否属于指定的宽高比，在C#或VB.NET。

目前我写的是：

/// --------------------------------------------------------------------------
/// <summary>
/// Determine whether the source resolution belongs to the specified aspect ratio.
/// </summary>
/// --------------------------------------------------------------------------
/// <param name="resolution">
/// The source resolution.
/// </param>
/// 
/// <param name="aspectRatio">
/// The aspect ratio.
/// </param>
/// --------------------------------------------------------------------------
/// <returns>
/// <see langword="true"/> if the source resolution belongs to the specified aspect ratio; 
/// otherwise, <see langword="false"/>.
/// </returns>
/// ----------------------------------------------------------------------------------------------------
public static bool ResolutionIsOfAspectRatio(Size resolution, Point aspectRatio) {

    return (resolution.Width % aspectRatio.X == 0) && 
           (resolution.Height % aspectRatio.Y == 0);

}

VB.NET:

Public Shared Function ResolutionIsOfAspectRatio(resolution As Size, 
                                                 aspectRatio As Point) As Boolean

    Return ((resolution.Width Mod aspectRatio.X) AndAlso 
            (resolution.Height Mod aspectRatio.Y)) = 0

End Function

用法示例：

Size resolution = new Size(1920, 1080);
Point aspectRatio = new Point(16, 9);

bool result = ResolutionIsOfAspectRatio(resolution, aspectRatio);

Console.WriteLine(result);

我只是想确保我没有遗漏任何纵横比概念，在使用我编写的函数时可能会导致意外结果。

那么，我的问题是：该算法是否适用于所有情况？如果不是，我应该做哪些修改才能正确执行此操作？

编辑：我注意到该算法完全错误，它采用 640x480 作为 16:9 纵横比。我没有充分了解如何计算这个的基础知识。

Answer 1

您的计算有误。仅 mod 每个值单独不验证纵横比。

例如

Size res = new Size(1920, 1080);
Point aspect = new Point(16, 9);  //1080%9==0 valid and true
bool result = (res.Width % aspect.X == 0) &&(res.Height % aspect.Y == 0);

是正确的，但

Point aspect = new Point(16, 10); //1080%10==0 invalid and true!

也是如此。

正确的计算方式是

bool result = res.Width / aspect.X == res.Height / aspect.Y; //1920/16 == 1080/9

判断源分辨率是否属于指定宽高比

Determine whether a source resolution belongs to the specified aspect ratio

c#

.net

vb.net

aspect-ratio

imaging