StringBuilder似乎没有Substring(start, len)方法...我漏掉了什么?
StringBuilder似乎没有Substring(start, len)方法...我漏掉了什么?
StringBuilder类有一个特殊版本的ToString方法,它接受两个参数,与Substring(startIndex, length)完全相同。
StringBuilder sb = new StringBuilder("This is a Test");
string test = sb.ToString(10, 4);
Console.WriteLine(test); // result = Test
StringBuilder b = new StringBuilder();
b.Append("some text to test out!");
string s = b.ToString(0, 6);
//or ....
char[] letters = new char[6];
b.CopyTo(0, letters, 0, 6);
string s1 = new string(letters);
//or
string s2 = null;
for (int i = 0; i < 6; i++)
{
s2 += b[i];
}
另一种方法是,如果您不想构建整个字符串(StringBuilder.ToString())并获取子字符串:
public static StringBuilder SubString(this StringBuilder input, int index, int length)
{
StringBuilder subString = new StringBuilder();
if (index + length - 1 >= input.Length || index < 0)
{
throw new ArgumentOutOfRangeException("Index out of range!");
}
int endIndex = index + length;
for (int i = index; i < endIndex; i++)
{
subString.Append(input[i]);
}
return subString;
}
return new StringBuilder(input.ToString(index, length));
。 - Steve
.Substring(0, sb.ToString().Length -1)
。 - jspinella