Delphi中的访问冲突? [英] Access violation in Delphi?

问题描述

我得到了以下代码，该代码应该正确访问矩阵位置，但是我总是遇到这种访问冲突...

I got the following code which is supposed to correctly acess the matrix positions, however I'm always getting this access violation...

var
tabla : array of array of string;

....
implementation

SetLength(tabla, minterms.Count+1, minterms_essentials.Count+1);

for i := 0 to minterms.Count-1 do
begin
  tabla[i+2,1] := minterms[i];
end;

for i := 0 to minterms_essentials.Count-1 do
begin
  tabla[1, i+2] := minterms_essentials[i];
end;

end

基本上，我正在生成一个表，并在循环中尝试在第二个循环中填充列标记和行标记.据我所知，数组从1开始.

Basically, I'm generating a table and in the loop I'm trying to fill the column tags and the row tags in second loop. As long as I know, arrays start in 1.

tabla[1][1]会是一个空置的索引，这就是为什么我没有触摸它的原因.

tabla[1][1] would an unoccupied index, that's why I'm ain't touching it.

为什么会发生访问冲突?

推荐答案

在Delphi中，动态数组(可在其上调用SetLength的任何数组，而不是像array[1..5] of integer那样在编译时声明其边界)都从以下索引开始0，而不是1.因此，通过将数组当作使用基于1的索引而不是基于0的索引来对待，就溢出了数组的边界，并尝试写入未分配给您的内存，这可能会导致访问冲突.

In Delp dynamic arrays (any array that you can call SetLength on, as opposed to declaring its bounds at compile time like array[1..5] of integer) are indexed starting from 0, not from 1. So by treating your array as if it used 1-based indexing instead of 0-based indexing, you're overflowing the bounds of the array and trying to write to memory that's not allocated to you, which can cause an access violation.

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