How to Count Strings in WPF

static int countOccurrence (string str, string word) 
{ 
    // split the string by spaces 
    string [ ] a = str.Split('); 

    // search for pattern instring 
    int count = 0; 

    for (inti=0; i<a.Length;i++) 
    { 
        // if match found increase count 
        if(word.Equals(a[i])) 
            count++; 
    } 

    return count; 
}