忽略一些句子畢竟文本字符串

Question

text = "Hi, this a simple test. For more information: bla balasfafa nureahreuahre"; 

我想忽略所有的文字For more information:後，使文本將

text ="Hi, this a simple test. For more information:"; 

對我來說，問題是，我不知道在For more information:開始的索引/位置處，在字For之前可以有很多單詞。

我該如何做到這一點？要做到這一點

Answer 1

simpliest方式是

string input = "Hi, this a simple test. For more information: bla balasfafa nureahreuahre"; 
string[] array = input.Split(new string[] { "For more information:" }, StringSplitOptions.RemoveEmptyEntries); 
string output = array[0] + "For more information:"; 

或

string input = "Hi, this a simple test. For more information: bla balasfafa nureahreuahre"; 
int lastIndex = input.LastIndexOf("For more information:"); 
var res = input.Substring(0, lastIndex + 21);