这是我的fractionalupdown示例代码。
一定要设置
DecimalPlaces
满足你的需要。
用
Mode
,可以选择值的格式:
-
EMode.Decimal
= & 2500;
-
EMode.Fractional
=>____
-
EMode.FractionalMixed
=>2_墋墋墋墋
-
EMode.FractionalASCII
= 5/2;
-
EMode.FractionalMixedASCII
=2;1/2
代码:
public class FractionalUpDown: NumericUpDown {
//Hide Hexadecimal
[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
[Bindable(false)]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public new bool Hexadecimal {
get { return false; }
set { base.Hexadecimal = false; }
}
private EMode mode;
[DefaultValue(EMode.Fractional)]
public EMode Mode {
get { return mode; }
set {
if (value != mode) {
mode = value;
UpdateEditText();
}
}
}
public enum EMode {
Fractional,
FractionalMixed,
FractionalASCII,
FractionalMixedASCII,
Decimal
}
public FractionalUpDown() {
}
protected override void UpdateEditText() {
if (Mode == EMode.Decimal) {
base.UpdateEditText();
return;
}
double accuracy = Math.Pow(10.0, -(DecimalPlaces + 1));
if (accuracy > 0.1) accuracy = 0.1;
this.Text = FractionToString(DoubleToFraction((double)Value, accuracy), Mode);
}
public struct Fraction {
public Fraction(int n, int d) {
N = n;
D = d;
}
public int N { get; private set; }
public int D { get; private set; }
}
private static readonly char[] numbers = new char[10] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
private static readonly char[] numerators = new char[10] { 'â°', '¹', '²', '³', 'â´', 'âµ', 'â¶', 'â·', 'â¸', 'â¹' };
private static readonly char[] denumerators = new char[10] { 'â', 'â', 'â', 'â', 'â', 'â
', 'â', 'â', 'â', 'â' };
protected string FractionToString(Fraction frac, EMode mode) {
int full = 0;
int n = frac.N;
string result = string.Empty;
bool mixed = mode == EMode.FractionalMixed ||
mode == EMode.FractionalMixedASCII;
bool useFractionalChars = mode == EMode.Fractional ||
mode == EMode.FractionalMixed;
if (mixed && Math.Abs(frac.N) >= frac.D) {
full = frac.N / frac.D;
n = Math.Abs(frac.N % frac.D);
if (full != 0) result = full.ToString();
else if (n == 0) return "0";
}
if (n != 0) {
string fracNtext = n.ToString();
string fracDtext = frac.D.ToString();
if (useFractionalChars) {
for (int i = 0; i < 10; i++) fracNtext = fracNtext.Replace(numbers[i], numerators[i]);
for (int i = 0; i < 10; i++) fracDtext = fracDtext.Replace(numbers[i], denumerators[i]);
} else {
if (full != 0) result += " ";
}
result += fracNtext + 'â' + fracDtext;
} else {
//Fractional Part == 0/?
if (full == 0) {
if (mixed == true) {
return "0";
} else {
if (useFractionalChars) {
return numerators[0].ToString() + 'â' + denumerators[1].ToString();
} else {
return numbers[0].ToString() + 'â' + numbers[1].ToString();
}
}
}
}
return result;
}
//Source: https://stackoverflow.com/questions/5124743/algorithm-for-simplifying-decimal-to-fractions/32903747#32903747
protected Fraction DoubleToFraction(double value, double accuracy) {
if (accuracy <= 0.0 || accuracy >= 1.0) {
throw new ArgumentOutOfRangeException("accuracy", "Must be > 0 and < 1.");
}
int sign = Math.Sign(value);
if (sign == -1) {
value = Math.Abs(value);
}
// Accuracy is the maximum relative error; convert to absolute maxError
double maxError = sign == 0 ? accuracy : value * accuracy;
int n = (int)Math.Floor(value);
value -= n;
if (value < maxError) {
return new Fraction(sign * n, 1);
}
if (1 - maxError < value) {
return new Fraction(sign * (n + 1), 1);
}
// The lower fraction is 0/1
int lower_n = 0;
int lower_d = 1;
// The upper fraction is 1/1
int upper_n = 1;
int upper_d = 1;
while (true) {
// The middle fraction is (lower_n + upper_n) / (lower_d + upper_d)
int middle_n = lower_n + upper_n;
int middle_d = lower_d + upper_d;
if (middle_d * (value + maxError) < middle_n) {
// real + error < middle : middle is our new upper
Seek(ref upper_n, ref upper_d, lower_n, lower_d, (un, ud) => (lower_d + ud) * (value + maxError) < (lower_n + un));
upper_n = middle_n;
upper_d = middle_d;
} else if (middle_n < (value - maxError) * middle_d) {
// middle < real - error : middle is our new lower
Seek(ref lower_n, ref lower_d, upper_n, upper_d, (ln, ld) => (ln + upper_n) < (value - maxError) * (ld + upper_d));
lower_n = middle_n;
lower_d = middle_d;
} else {
// Middle is our best fraction
return new Fraction((n * middle_d + middle_n) * sign, middle_d);
}
}
}
/// <summary>
/// Binary seek for the value where f() becomes false.
/// Source: https://stackoverflow.com/questions/5124743/algorithm-for-simplifying-decimal-to-fractions/32903747#32903747
/// </summary>
protected void Seek(ref int a, ref int b, int ainc, int binc, Func<int, int, bool> f) {
a += ainc;
b += binc;
if (f(a, b)) {
int weight = 1;
do {
weight *= 2;
a += ainc * weight;
b += binc * weight;
}
while (f(a, b));
do {
weight /= 2;
int adec = ainc * weight;
int bdec = binc * weight;
if (!f(a - adec, b - bdec)) {
a -= adec;
b -= bdec;
}
}
while (weight > 1);
}
}
}
