有3个打开的窗体,主窗体 mdiMain 子窗体(显示字段变化窗体)FrmShow 中listBox1设置为公有的, 另一个操作子窗体 FrmZDZ 我在主窗体 mdiMain窗体中写
private FrmShow childformShow;
private void button1_Click(object sender, EventArgs e)
{
FrmShow form = (FrmShow)this.childformShow;
form.listBox1.Items.Add("要显示的字段");
} 以上操作正常 但我又在另一个操作窗体 FrmZDZ 写,则出现错误 private FrmShow childformShow;
private void button1_Click(object sender, EventArgs e)
{
FrmShow form = (FrmShow)this.childformShow;
form.listBox1.Items.Add("要显示的字段");
}
错误为:未将对象引用设置到对象的实例。请帮忙一下好吗?
private FrmShow childformShow;
private void button1_Click(object sender, EventArgs e)
{
FrmShow form = (FrmShow)this.childformShow;
form.listBox1.Items.Add("要显示的字段");
} 以上操作正常 但我又在另一个操作窗体 FrmZDZ 写,则出现错误 private FrmShow childformShow;
private void button1_Click(object sender, EventArgs e)
{
FrmShow form = (FrmShow)this.childformShow;
form.listBox1.Items.Add("要显示的字段");
}
错误为:未将对象引用设置到对象的实例。请帮忙一下好吗?
FrmShow form = (FrmShow)this.parent.childformShow
FrmShow form = (FrmShow)this.parent.childformShow 别 .parent.后面没有这个childformShow
private FrmShow childformShow;
private void button1_Click(object sender, EventArgs e)
{
FrmShow form = new FrmShow();
form.listBox1.Items.Add("要显示的字段");
} FrmShow 不是子窗体