为什么MdiParent为null? [英] Why is MdiParent null?
问题描述
Form1 f1 = new Form1();
f1是主要表格
f1是Mdi容器;
Form2 f2 = new Form2();
f2.MdiParent = this;
f2.show();
现在,在f2的构造函数中我有:
Form1 f1 =(Form1)this.MdiParent; //错误
但是MdiParent是NULL ...
为什么?
谢谢...
Form1 f1=new Form1();
f1 is the main form
f1 is an Mdi Container;
Form2 f2=new Form2();
f2.MdiParent=this;
f2.show();
Now, in constructor of the f2 I have:
Form1 f1=(Form1)this.MdiParent; // ERROR
But MdiParent is NULL...
Why?
Thank you...
推荐答案
因为它在构造函数中。看看你的代码:
Because it is in the constructor. Look at your code:
Form2 f2=new Form2();
f2.MdiParent=this;
在执行第二条指令之前,两行的第一行调用Form2的构造函数。
考虑将代码从构造函数移入Form2.Load或Form2.Shown事件。
错字:Lein代表Line - OriginalGriff [/ edit]
The first line of the two calls the constructor for Form2, before the second instruction is executed.
Consider moving your code from the constructor into the Form2.Load or Form2.Shown events.
[edit]Typo: "Lein" for "Line" - OriginalGriff[/edit]
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