C# 将文本框中的文本格式化为百分比
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原文地址: http://stackoverflow.com/questions/849799/
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Format Text from a Textbox as a Percent
提问by
I have a numeric value in a Textboxthat I'd like to format as a percent. How can I do this in C# or VB.NET?
我在 aTextbox中有一个数值，我想将其格式化为百分比。如何在 C# 或 VB.NET 中执行此操作？
采纳答案by Larsenal
In VB.NET...
在 VB.NET 中...
YourTextbox.Text = temp.ToString("0%")
And C#...
和 C#...
YourTextbox.Text = temp.ToString("0%");
回答by Joe H
Building on Larsenal's answer, how about using the TextBox.Validating event something like this:
基于 Larsenal 的回答，如何使用 TextBox.Validating 事件，如下所示：
yourTextBox_Validating(object sender, CancelEventArgs e)
{
double doubleValue;
if(Double.TryParse(yourTextBox.Text, out doubleValue))
{
yourTextBox.Text = doubleValue.ToString("0%");
}
else
{
e.Cancel = true;
// do some sort of error reporting
}
}
回答by Frank Krueger
For added fun, let's make the parser a bit more sophisticated.
为了增加乐趣，让我们让解析器更复杂一点。
Instead of Double.TryParse, let's create Percent.TryParsewhich passes these tests:
而不是Double.TryParse，让我们创建Percent.TryParse通过这些测试的：
100.0 == " 100.0 "
55.0 == " 55% "
100.0 == "1"
1.0 == " 1 % "
0.9 == " 0.9 % "
90 == " 0.9 "
50.0 == "50 "
1.001 == " 1.001"
I think those rules look fair if I was a user required to enter a percent. It allows you to enter decimal values along with percents (requiring the "%" end char or that the value entered is greater than 1).
如果我是需要输入百分比的用户，我认为这些规则看起来很公平。它允许您输入十进制值和百分比（需要“%”结束字符或输入的值大于1）。
public static class Percent {
static string LOCAL_PERCENT = "%";
static Regex PARSE_RE = new Regex(@"([\d\.,]+)\s*("+LOCAL_PERCENT+")?");
public static bool TryParse(string str, out double ret) {
var m = PARSE_RE.Match(str);
if (m.Success) {
double val;
if (!double.TryParse(m.Groups[1].Value, out val)) {
ret = 0.0;
return false;
}
bool perc = (m.Groups[2].Value == LOCAL_PERCENT);
perc = perc || (!perc && val > 1.0);
ret = perc ? val : val * 100.0;
return true;
}
else {
ret = 0.0;
return false;
}
}
public static double Parse(string str) {
double ret;
if (!TryParse(str, out ret)) {
throw new FormatException("Cannot parse: " + str);
}
return ret;
}
public static double ParsePercent(this string str) {
return Parse(str);
}
}
Of course, this is all overkill if you simply put the "%" sign outsideof the TextBox.
当然，这是如果你简单地把“％”符号所有矫枉过正之外的TextBox。
回答by Frank Krueger
A little trickery for populating Label's (& TexBox) in a panel before users input. This covers decimal, integers, percent, and strings.
在用户输入之前在面板中填充标签（和 TexBox）的小技巧。这包括小数、整数、百分比和字符串。
Using C# 1.1 in the Page_Load event before any thing happens:
在任何事情发生之前在 Page_Load 事件中使用 C# 1.1：
if (!this.IsPostBack)
{
pnlIntake.Vissible=true' // what our guest will see & then disappear
pnlResult.Vissible=false" // what will show up when the 'Submit' button fires
txtIperson.Text = "enter who";
lbl1R.Text = String.Format(Convert.ToString(0)); // how many times
lbl2R.Text = String.Format(Convert.ToString(365)); // days a year
lblPercentTime = String.Format("{0:p}", 0.00); // or one zero will work '0'
lblDecimal = String.Format("{0:d}", 0.00); // to use as multiplier
lblMoney = String.Format("{0:c}", 0.00); // I just like money
< some code goes here - if you want >
}
