未將對象引用設置到對象的實例
對象引用沒有設置到對象實例的原因很多:
待續。。。
1、如下:
public int Revise(ref int numline, ref int numcircle, ref int numtext,System.IO.StreamWriter str_w, List< string >
record,EXT extend,Line []
lines, Circle[] circles, Text []
texts)
{
string []
record1 =record.ToArray();
for (int i
= 0; i < record1.Length;i++ )
{
string temp
= string .Empty;
temp = record1[i];
if (temp
== "$EXTMIN" )
{
record1[i + 2] = Convert .ToString(extend.Min_x)
;
record1[i + 4] = Convert .ToString(extend.Min_y);
record1[i + 6] = Convert .ToString(extend.min_z);
record1[i + 10] = Convert .ToString(extend.Max_x);
record1[i + 12] = Convert .ToString(extend.Max_y);
record1[i + 14] = Convert .ToString(extend.Max_z);
i += 14;
continue ;
}
if (temp
== "AcDbLine" )
{
record1[i + 2]= Convert .ToString(lines[numline].x1);//此處開始報錯
record1[i + 4] = Convert .ToString(lines[numline].y1);
record1[i + 6] = Convert .ToString(lines[numline].z1);
record1[i + 8] = Convert .ToString(lines[numline].x2);
record1[i + 10] = Convert .ToString(lines[numline].y2)
;
record1[i + 12] = Convert .ToString(lines[numline].z2);
numline--;
i += 12;
continue ;
}
}
for (int i
= 0; i < record1.Length;i++ )
{
str_w.WriteLine(record1[i]);
}
return 1;
}
其中numline,numcircle,numtext,代表的line,circle,text對象的個數
原因就在於,數組的下標總是比個數小1,假如有5個元素,我們嘗試給lines[5]賦值,而lines[5]已經越界,更不可能初始化。
2、對於數組,不光要實例化數組,還要實例化數組的對象
public int Read_Entities(ref int numpolyline, Polyline []
plines,System.IO. StreamReader str_r)
{
string buff
= string .Empty;
buff = str_r.ReadLine();
//int numline
= 0;
//int numcircle
= 0;
//int numtext=0;
while (buff
!= "OBJECTS" )
{
if (buff
== "LWPOLYLINE" )
{
while (buff
!= "AcDbPolyline" )
{
buff = str_r.ReadLine();
}
plines[numpolyline] = new Polyline ();//(1)
str_r.ReadLine();
plines[numpolyline].pointnum = Convert .ToInt32(str_r.ReadLine());
str_r.ReadLine();
str_r.ReadLine();
str_r.ReadLine();
str_r.ReadLine();
plines[numpolyline].points = new point [plines[numpolyline].pointnum];//(2)
for (int i=0;i<plines[numpolyline].pointnum;i++)
{
plines[numpolyline].points[i] = new point ();//(3)
str_r.ReadLine();
plines[numpolyline].points[i].x = Convert .ToDouble(str_r.ReadLine());
str_r.ReadLine();
plines[numpolyline].points[i].y = Convert .ToDouble(str_r.ReadLine());
}
}
buff = str_r.ReadLine();
}
return 1;
}
其中,多線由多個點組成
註釋(1)處:初始化polyline對象
註釋(2)處:初試化point數組
註釋(3)處:初始化點對象實例
一直忘記了第二個,導致一直提示錯誤
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