我有一个应用程序，当在家里运行时工作正常，但是当在学校计算机（Windows XP）上运行时，我收到以下消息。 （这是重新编译它，而不仅仅是运行.exe） - 在Delphi 2005中
$ 7C81EB33的首次机会异常。异常类EAccessViolation，消息'模块'Project2.exe'中地址0045E5E2的访问冲突。读取地址00000198'。处理Project2.exe（440）
代码：忽略不需要的东西。
Image1: TImage; // Image(all the way to 72)
Timer1: TTimer; Timer2: TTimer;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure SomeOtherProcedure(Sender: TImage);
procedure Timer1Timer(Sender: TObject);
procedure Timer2Timer(Sender: TObject);
private
{ private declarations }
public
{ public declarations }
end;
var
Form1: TForm1;
left : integer;
top : integer;
gap : integer;
type
coordinates = record
row : integer ;
col : integer;
end;
var
picarray : array[0..5,0..5] of timage;
thiscover, midcover, lastcover : timage;
imageindex : array[0..5,0..5] of integer;
picloc: array[0..3] of coordinates;
clickcount, pairsfound, attemptcount : integer;
implementation
{$R *.lfm}
procedure initialise();
var
i, j, whichcol, whichrow : integer;
begin
for i := 0 to 5 do
for j := 0 to 5 do
imageindex[i,j] := -1; // not used
randomize;
for i := 0 to 11 do
for j := 1 to 3 do
begin
repeat
begin
whichcol := random(6) ;
whichrow := random(6) ;
end;
until imageindex[whichcol, whichrow] = -1;
picarray[whichcol, whichrow].Picture.LoadFromFile('C:\Users\Hayden\Pictures\'+ inttostr(I+1) +'.jpg');
imageindex[whichcol, whichrow] := I ;
end;
clickcount := 0 ; //
pairsfound := 0 ;
attemptcount := 0 ;
end;
procedure TForm1.FormCreate(Sender: TObject);
var
cpic : tcomponent;
whichcol: integer;
whichrow : integer;
begin
gap := image2.left - image1.left;
top := image1.Top;
left := image1.left;
for cpic in form1 do
begin
if (cpic.ClassType = timage) and (cpic.Tag = 10) then
begin
whichcol := (timage(cpic).left - left) div gap;
whichrow := (timage(cpic).Top - top) div gap;
picarray[whichcol, whichrow] := timage(cpic) ;
end;
end;
initialise;
end;
行＆gt;＆gt;＆gt; picarray [whichcol，whichrow] .Picture.LoadFromFile（'C：\ Users \ Hayden \ Pictures \'+ inttostr（I + 1）+'。jpg'）; 似乎导致错误。如果是编码错误，那么正确的方法是什么？
答案 0 :(得分：3)
首先，我要稍微清理你的代码，因为就目前来说，很难弄清楚发生了什么。我强烈建议您养成花几分钟时间来保持代码清晰格式的习惯 - 这样可以节省数小时的调试时间。
我只应用了以下简单的更改：缩进，空行和begin .. end;
var
picarray : array[0..5,0..5] of timage;
thiscover, midcover, lastcover : timage;
imageindex : array[0..5,0..5] of integer;
picloc: array[0..3] of coordinates;
clickcount, pairsfound, attemptcount : integer;
implementation
{$R *.lfm}
procedure initialise();
var
i, j, whichcol, whichrow : integer;
begin
for i := 0 to 5 do
begin
for j := 0 to 5 do
begin
//It's clear you're initialising the 36 entries of imageindex to -1
imageindex[i,j] := -1; // not used
end;
end;
randomize;
for i := 0 to 11 do
begin
for j := 1 to 3 do
begin
//This loop also runs 36 times, so it fills the whole of imageindex with new values
//It also loads all 36 entries of picarray with an image specfied by the current value of i
//The approach is dangerous because it depends on the 'loop sizes' matching,
//there are much safer ways of doing this, but it works
repeat
begin //This being one of the only 2 begin..end's you provided inside this is routine is pointless because repeat..until implies it.
whichcol := random(6) ;
whichrow := random(6) ;
end;
until imageindex[whichcol, whichrow] = -1;
//This line itself will throw an access violation if picarray[whichcol, whichrow] doesn't
//contain a valid TImage instance... we have to check other code to confirm that possibility
picarray[whichcol, whichrow].Picture.LoadFromFile('C:\Users\Hayden\Pictures\' + inttostr(I+1) + '.jpg');
imageindex[whichcol, whichrow] := I ;
end;
end;
clickcount := 0 ; //
pairsfound := 0 ;
attemptcount := 0 ;
end;
转到下一段代码：
procedure TForm1.FormCreate(Sender: TObject);
var
cpic : tcomponent;
whichcol: integer;
whichrow : integer;
begin
gap := image2.left - image1.left;
top := image1.Top;
left := image1.left;
for cpic in form1 do
begin
//This loop attempts to assign existing TImage instances to picarray
//However, the way you're going about it is extremely dangerous and unreliable.
//You're trying to use the position of a component on the form to determine its
//position in the array.
//There are many things that could go wrong here, but since this seems to be a
//homework excercise, I'll just point you in the right direction - you need
//to debug this code.
if (cpic.ClassType = timage) and (cpic.Tag = 10) then
begin
whichcol := (timage(cpic).left - left) div gap;
whichrow := (timage(cpic).Top - top) div gap;
picarray[whichcol, whichrow] := timage(cpic) ;
end;
end;
//Here you call initialise, which as I said before, will
//cause an Access Violation if picarray is not correctly 'set up'
//The previous code in this method certainly has a bug which is
//preventing one or more picarray entries from being assigned a
//valid TImage instance.
//You could write a simple for I := 0 to 5, for J := 0 to 5 loop
//here to check each of picarray entries and pinpoint which is
//incorrect to aid your debugging of the pevious loop.
initialise;
end;
答案 1 :(得分：2)
关键部分是picarray的初始化。您不能确定每个数组元素都分配有TImage组件。如果至少有一个图片有错误left或top，则您对一个元素进行了双重赋值，而另一个图片则为零。这将在您第一次使用时导致访问冲突，例如在picarray[whichcol, whichrow].Picture.LoadFromFile。
我建议用每个维度的for循环重新设计picarray初始化。为了得到正确的TImage，我将它们命名为'Image_2_3'，并按名称获取循环中的实例。
答案 2 :(得分：1)
您可以检查文件是否存在并尝试捕获异常以显示有意义的消息
try
if FileExists('C:\Users\Hayden\Pictures\'+ inttostr(I+1) +'.jpg') then
picarray[whichcol, whichrow].Picture.LoadFromFile('C:\Users\Hayden\Pictures\'+ inttostr(I+1) +'.jpg');
else
ShowMessage("File not found");
except
on E : Exception do
ShowMessage(E.ClassName+' error raised, with message : '+E.Message);
end;