此方法用于返回一个单精度浮点数，该浮点数是从字节数组中指定位置的四个字节转换而来的。
句法：
public static float ToSingle (byte[] value, int startIndex);参数：
value: It is an array of bytes.
startIndex: It is the starting position within value.
返回值：该方法返回一个由startIndex开始的四个字节组成的单精度浮点数。
例外情况：
- ArgumentException：如果startIndex大于或等于值的长度减去3，并且小于或等于值的长度减去1。
- ArgumentNullException：如果该值为null。
- ArgumentOutOfRangeException：如果startIndex小于零或大于值的长度减去1。
下面的程序说明了BitConverter.ToSingle(Byte []，Int32)方法的用法：
范例1：
// C# program to demonstrate
// BitConverter.ToSingle(Byte[], Int32)
// Method
using System;
class GFG {
// Main Method
public static void Main()
{
try {
// Define an array of byte values.
byte[] bytes = {0, 128, 63, 0, 0,
112, 65, 0, 255,
127, 71, 0, 0,
128, 59, 0, 0,
128, 47, 73, 70,
131, 5, 75, 6,
158, 63};
// Display the values of the myArr.
Console.Write("Initial Array: ");
// calling the PrintIndexAndValues()
// method to print
PrintIndexAndValues(bytes);
// print char value
Console.WriteLine("index Array elements float values");
Console.WriteLine();
// getting float value and Display it
for (int index = 0; index < bytes.Length - 3;
index = index + 4) {
float values = BitConverter.ToSingle(bytes, index);
Console.WriteLine(" {0} {1} {2}",
index, BitConverter.ToString(bytes,
index, 4), values);
}
}
catch (ArgumentNullException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentOutOfRangeException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(byte[] myArr)
{
for (int i = 0; i < myArr.Length; i++) {
Console.Write("{0} ", myArr[i]);
}
Console.WriteLine();
Console.WriteLine();
}
}
输出：
Initial Array: 0 128 63 0 0 112 65 0 255 127 71 0 0 128 59 0 0 128 47 73 70 131 5 75 6 158 63
index Array elements float values
0 00-80-3F-00 5.831554E-39
4 00-70-41-00 6.009485E-39
8 FF-7F-47-00 6.566237E-39
12 00-80-3B-00 5.464212E-39
16 00-80-2F-49 718848
20 46-83-05-4B 8749894
示例2：对于ArgumentException
// C# program to demonstrate
// BitConverter.ToSingle(Byte[], Int32)
// Method
using System;
class GFG {
// Main Method
public static void Main()
{
try {
// Define an array of byte values.
byte[] bytes ={0, 128, 63, 0, 0,
112, 65, 0, 255,
127, 71, 0, 0,
128, 59, 0, 0,
128, 47, 73, 70,
131, 5, 75, 6,
158, 63};
// Display the values of the myArr.
Console.Write("Initial Array: ");
// calling the PrintIndexAndValues()
// method to print
PrintIndexAndValues(bytes);
// print char value
Console.WriteLine("index Array elements"+
" float values");
Console.WriteLine();
// getting float value and Display it
for (int index = 0; index < bytes.Length - 2;
index = index + 4) {
if (index == bytes.Length - 3) {
Console.WriteLine();
Console.WriteLine("startIndex is equal to"+
" the length of bytes minus 3");
float values = BitConverter.ToSingle(bytes, index);
Console.WriteLine(" {0} {1} {2}",
index, BitConverter.ToString(bytes,
index, 4), values);
}
else {
float values = BitConverter.ToSingle(bytes, index);
Console.WriteLine(" {0} {1} {2}",
index, BitConverter.ToString(bytes,
index, 4), values);
}
}
}
catch (ArgumentNullException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentOutOfRangeException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(byte[] myArr)
{
for (int i = 0; i < myArr.Length; i++) {
Console.Write("{0} ", myArr[i]);
}
Console.WriteLine();
Console.WriteLine();
}
}
输出：
Initial Array: 0 128 63 0 0 112 65 0 255 127 71 0 0 128 59 0 0 128 47 73 70 131 5 75 6 158 63
index Array elements float values
0 00-80-3F-00 5.831554E-39
4 00-70-41-00 6.009485E-39
8 FF-7F-47-00 6.566237E-39
12 00-80-3B-00 5.464212E-39
16 00-80-2F-49 718848
20 46-83-05-4B 8749894
startIndex is equal to the length of bytes minus 3
Exception Thrown: System.ArgumentException
示例3：对于ArgumentOutOfRangeException
// C# program to demonstrate
// BitConverter.ToSingle(Byte[], Int32)
// Method
using System;
using System.Collections.Generic;
public class GFG {
// Main Method
public static void Main()
{
try {
// Define an array of byte values.
byte[] bytes = {0, 128, 63, 0, 0, 112, 65,
0, 255, 127, 71, 0, 0, 128,
59, 0, 0, 128, 47, 73, 70,
131, 5, 75, 6, 158, 63, 24};
// Display the values of the myArr.
Console.Write("Initial Array: ");
// calling the PrintIndexAndValues()
// method to print
PrintIndexAndValues(bytes);
// print char value
Console.WriteLine("index Array elements float values");
Console.WriteLine();
// getting float value and Display it
for (int index = 0; index < bytes.Length + 1;
index = index + 4) {
if (index == bytes.Length) {
Console.WriteLine();
Console.WriteLine("startIndex is greater than "+
"the length of bytes minus 1.");
float values = BitConverter.ToSingle(bytes, index);
Console.WriteLine(" {0} {1} {2}",
index, BitConverter.ToString(bytes,
index, 4), values);
}
else {
float values = BitConverter.ToSingle(bytes, index);
Console.WriteLine(" {0} {1} {2}",
index, BitConverter.ToString(bytes,
index, 4), values);
}
}
}
catch (ArgumentNullException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentOutOfRangeException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(byte[] myArr)
{
for (int i = 0; i < myArr.Length; i++) {
Console.Write("{0} ", myArr[i]);
}
Console.WriteLine();
Console.WriteLine();
}
}
输出：
Initial Array: 0 128 63 0 0 112 65 0 255 127 71 0
0 128 59 0 0 128 47 73 70 131 5 75
6 158 63 24
index Array elements float values
0 00-80-3F-00 5.831554E-39
4 00-70-41-00 6.009485E-39
8 FF-7F-47-00 6.566237E-39
12 00-80-3B-00 5.464212E-39
16 00-80-2F-49 718848
20 46-83-05-4B 8749894
24 06-9E-3F-18 2.476595E-24
startIndex is greater than the length of bytes minus 1.
Exception Thrown: System.ArgumentOutOfRangeException
示例4：对于ArgumentNullException
// C# program to demonstrate
// BitConverter.ToSingle(Byte[], Int32)
// Method
using System;
class GFG {
// Main Method
public static void Main()
{
try {
// Define an array of byte
// values with null value
byte[] bytes = null;
// getting the float value
float values = BitConverter.ToSingle(bytes, 0);
Console.Write("{0}", values);
}
catch (ArgumentNullException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentOutOfRangeException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
catch (ArgumentException e) {
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
}
输出：
Exception Thrown: System.ArgumentNullException参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.bitconverter.tosingle?view=netframework-4.7.2