VB將長度從英制轉換爲公制

Question

你好，我試圖將英寸轉換爲釐米，英里和英尺轉換正確，但釐米返回值爲0.任何意見，爲什麼我可能會遇到這個問題？

Dim totalInches, totalMeters As Long 
    Dim km, m As Double 
    Dim cm As Decimal 
    Dim result As String 

    totalInches = 63360 * miles + 36 * yards + 12 * feet + inches 
    totalMeters = totalInches/39.37 
    km = Int(totalMeters/1000) 
    m = Int(totalMeters - (km * 1000)) 
    cm = (totalMeters - (km * 1000) - m) * 100 

    result = "The Metric Length is:" + vbNewLine _ 
     + km.ToString + " Kilometers" + vbNewLine _ 
     + m.ToString + " Meters" + vbNewLine _ 
     + cm.ToString + " Centimeters"  

Answer 1

當您在totalInches和常量39.37之間進行劃分時，您正在使用長整數。這有效地截斷了結果的小數部分。

當然，如果您在項目屬性中使用Option Strict On，那麼您將永遠不會發生此錯誤，因爲您的代碼無法編譯。

在這兩種情況下，你需要兩個變化

Public Function ConvertImperialToMetric(miles as Integer, yards as Integer, feet as Integer, inches as Integer) as String 

    Dim totalInches as Long 

    ' totalMeters should be a double 
    Dim totalMeters As Double 
    Dim km, m As Double 
    Dim cm As Double 
    Dim result As String 

    totalInches = 63360 * miles + 36 * yards + 12 * feet + inches 

    ' With totalMeters as Double you don't loose the decimal part of the division 
    totalMeters = totalInches/39.37 
    km = Int(totalMeters/1000) 
    m = Int(totalMeters - (km * 1000)) 
    cm = (totalMeters - (km * 1000) - m) * 100 

    result = "The Metric Length is:" + vbNewLine _ 
     + km.ToString + " Kilometers" + vbNewLine _ 
     + m.ToString + " Meters" + vbNewLine _ 
     + cm.ToString + " Centimeters"  
    return result 
End Function