英文:
C# Truncating a string to 1 or 2 places after decimal without converting?
问题
The code you provided is in C# and it appears that you're looking for a way to truncate decimal values in certain strings to two decimal places. To achieve this without converting to a decimal and back, you can use the following one-liner for those specific lines:
items[x] = $"{items[x]:F2}";
This will format the string in items[x] to have exactly two decimal places without needing to convert it to a decimal type.
Please note that this line should replace the lines like newcomp.Range = items[2].Substring(0, items[2].IndexOf('.')) + 3); for the six values you mentioned.
英文:
I am receiving a csv string that I need to display in a .Net6.0 wpf ListView. I'm processing thousands of strings per second, and would like a quick way to truncate a string after the decimal for six of the values in the string. I know that I can convert to a number, but this seems bulky, especially since I would have to convert back to string for display. Here is my function:
public void AddComponent(string component){Component newcomp = new Component();string[] items = component.Split(',');newcomp.Time = items[0].Substring(items[0].IndexOf(':') + 1);newcomp.CompId = items[1];newcomp.Range = items[2].Substring(0, items[2].IndexOf('.') + 3);newcomp.Diameter = items[3].Substring(0, items[3].IndexOf('.') + 3);newcomp.Radius = items[4].Substring(0, items[4].IndexOf('.') + 3);newcomp.Height = items[5];newcomp.Validity = EnumExtensions.GetDescription((ComponentValidity)(ushort.Parse(items[6])));newcomp.Value = items[7];newcomp.RCS = items[8];newcomp.Status = EnumExtensions.GetDescription((ComponentStatus)ushort.Parse(items[9].Substring(0, 1)));newcomp.Confidence = EnumExtensions.GetDescription((ComponentConfidence)ushort.Parse(items[9].Substring(3, 1)));newcomp.MNF = items[10].Substring(0, items[10].IndexOf('.') + 3);newcomp.Group = items[11];newcomp.Classification = EnumExtensions.GetDescription((ComponentClassification)(ushort.Parse(items[12])));newcomp.Serial = items[13];newcomp.ShelfNumber = items[14].Substring(0, items[14].IndexOf('.') + 3);newcomp.HYT = items[15].Substring(0, items[15].IndexOf('.') + 3);Components.Add(newcomp);}
The main ones I'm concerned about are the six that do this:
items[x].Substring(0, items[x].IndexOf('.') + 3);
These numbers can look like:
34.234.2434.245676765.2232
I want the end result to be
34.234.2434.2476765.22
And of course the problem is the + 3 on the end of the line because sometimes there aren't enough characters to fill that out.
I'm already parsing some of the items to get the enum values, so I would rather not convert these strings to a decimal and back again. Is there an easy one-liner that might accomplish this?
答案1
得分: 0
我找到了一种很好用的两行代码：
int index = items[2].IndexOf('.');newcomp.Range = items[2].Substring(0, index + (items[2].Length - index > 3 ? 3 : items[2].Length - index));
编辑
将Matthew Watson的示例与这两行代码结合起来，并考虑到可能没有小数点，我得到了以下代码：
int index = items[2].IndexOf('.');newcomp.Range = index == -1 ? items[2] : items[2][..Math.Min(items[2].Length, index + 3)];
英文:
I figured out a two-liner that works pretty well:
int index = items[2].IndexOf('.');newcomp.Range = items[2].Substring(0, index + (items[2].Length - index > 3 ? 3 : items[2].Length - index));
EDIT
Combining Matthew Watson's samples with this two-line approach, and taking into account there may not be a decimal point at all, I get:
int index = items[2].IndexOf('.');newcomp.Range = index == -1 ? items[2] : items[2][..Math.Min(items[2].Length, index + 3)];
答案2
得分: 0
也许是这样的？
var tempNumber = items[x] + "0"; tempNumber.Substring(0, tempNumber.IndexOf('.') + 3);
英文:
Perhaps something like this?
var tempNumber = items[x]+"0";
tempNumber.Substring(0, itempNumber.IndexOf('.') + 3);
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