在C＃1中从MDI父级调用MDI Child的方法

Question

In first step login form in MDI container. It works well. After login next Message form show "out of" MDI container. I want to show also message form in MDI container.

    // MDI code
    private void Form1_Load(object sender, EventArgs e)
    {
        Form2 login = new Form2();
        login.MdiParent = this;
        login.Show();            
    }
    // Login button code
    private void button1_Click(object sender, EventArgs e)
    {
        if (textBox1.Text == "admin" && textBox2.Text == "123")
        {
            Form3 message = new Form3();                
            this.Hide();
            message.Show();
        }
    }

Answer 1

如果您打算在MDI容器中显示表单，请执行

    message.MdiParent = login.MdiParent;