off-by-one

来源： https://stackoverflow.com/questions/56610989/freezing-rows-in-sheets-with-google-apps-throws-type-error

问题 I have a DataGrid of variable dimensions dependent upon screen-res. I need to know how many rows are visible to the user. Here's my code: uint VisibleRows = 0; var TicketGrid = (DataGrid) MyWindow.FindName("TicketGrid"); foreach(var Item in TicketGrid.Items) { var Row = (DataGridRow) TicketGrid.ItemContainerGenerator.ContainerFromItem(Item); if(Row != null && Row.IsVisible) { VisibleRows++; } } I'm using the following code to test the vars: MessageBox.Show(String.Format("{0} of {1} rows

问题 I have a DataGrid of variable dimensions dependent upon screen-res. I need to know how many rows are visible to the user. Here's my code: uint VisibleRows = 0; var TicketGrid = (DataGrid) MyWindow.FindName("TicketGrid"); foreach(var Item in TicketGrid.Items) { var Row = (DataGridRow) TicketGrid.ItemContainerGenerator.ContainerFromItem(Item); if(Row != null && Row.IsVisible) { VisibleRows++; } } I'm using the following code to test the vars: MessageBox.Show(String.Format("{0} of {1} rows

问题 I want to store the binary value of each character in a string and store it in an array. But when i start messing around with functions like memset , i have no control over the debugging. #include <stdio.h> #include <string.h> int main() { char str[8]; char *ptr = "Hello"; int i; for(; *ptr != 0; ++ptr) { printf("%c => ", *ptr); /* perform bitwise AND for every bit of the character */ for(i = 7; i >= 0; --i) if(*ptr & 1 << i) str[7-i]='1'; else str[7-i]='0'; //(*ptr & 1 << i) ? putchar('1') :

问题 I'm seeing a strange issue involving a JLabel that is used to display a range of numbers. The text of the label is typically something like 0.0 - 100.0 (for example). The problem is that for a select few users, the text appears garbled. In this example, the text would show up as /-/,0//-/ . Here's what I know so far: It appears to be some sort of off-by-one bug since each character displayed is one Unicode character behind the expected character. The dash character between the two numbers is

问题 I declare my array Dim A(N) As Integer When I loop from 1 To N or 0 To N-1 there's an extra value at one end or the other. What's going on? (Intended to be a canonical question/answer.) 回答1: In VB.NET arrays almost always* have a lower bound of 0 and are declared mentioning their upper bound, not their length. They did change the VB.NET syntax early on to allow you to remind yourself if needed: Dim A(0 To N) As Integer That 0 can't be anything else (such as a 1 or a constant zero). You can