A small example of C # using StringBuilder to promote string concatenation performance

Monitored with stopwatch, the most time-consuming function was found Savetoexcel

This function lists all the rows of data, builds the Excel row with the Replace tag, and assigns the row data to a string

Copy Code code as follows:
String excelstring = "";
foreach (var item in list) {
excelstring = = String. Format ("<row> .....") {0}</row> ", list. Title);
}

See this. Immediately think of countless martyrs of the warning, string concatenation of memory operation principle and so on. So the big hand a wave, the code all deleted, change to the following form

Copy Code code as follows:
String excelstring = new StringBuilder ();
foreach (var item in list) {
Excelstring.appendformat ("<ROW> {0}</row> ", list. Title);
}

Again, the efficiency was increased dozens of times times. The previous 8000 lines need 30s and now only need 2s