您不清楚

但请尝试以下代码:

form2 frm2 = new form2();
frm2.mdiparent = form2;
(或frm2.mdiparent = frm3.mdiparent;//取决于您的表单)

your are not clear

but try this code:

form2 frm2 = new form2();
frm2.mdiparent = form2;
(or frm2.mdiparent = frm3.mdiparent; //depends on your forms )

您知道，这就像是重新发布...

Ya know, this looks like a repost...