WinForm給彈窗添加遮罩層

在Web項目中往往有非常多漂亮的彈窗控件，例如Layer。而Winform中比較常見的是用MessageBox來顯示彈框，但這樣的彈窗卻缺少遮罩效果，今天爲大家帶來的就是彈框的遮罩效果Demo。

效果如下：

完成這個功能需要三個Form窗體：

MainForm主界面後臺代碼如下：

    public partial class MainForm : Form
    {
        
        public MainForm()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            MessageForm form = new MessageForm();
            form.HideMaskAction += () => {
                //點擊按鈕關閉遮罩層
                this.HideMask();
            };
            this.ShowMask();
            if(form.ShowDialog() == DialogResult.OK)
            {
                //正常關閉
                this.HideMask();
                form.Dispose();
            }
        }

        private MaskForm _maskform;

        /// <summary>
        /// 顯示遮罩層
        /// </summary>
        private void ShowMask()
        {
            _maskform = new MaskForm(this.Location,this.Size);
            _maskform.Show();
        }

        /// <summary>
        /// 關閉遮罩層
        /// </summary>
        private void HideMask()
        {
            if(_maskform != null)
            {
                _maskform.Close();
            }
        }

}

MaskForm遮罩層代碼如下：

    public partial class MaskForm : Form
    {
        public MaskForm(Point point, Size size)
        {
            InitializeComponent();
            this.Opacity = 0.5;
            this.BackColor = Color.LightGray;
            this.FormBorderStyle = FormBorderStyle.None;
            this.StartPosition = FormStartPosition.Manual;
            //位置和大小跟隨主界面
            this.Location = point;
            this.Size = size;
        }

        private void MaskForm_FormClosed(object sender, FormClosedEventArgs e)
        {
            this.Dispose();
        }
    }

MessageForm彈窗代碼如下：

    public partial class MessageForm : Form
    {

        public Action HideMaskAction { get; set; }

        public MessageForm()
        {
            InitializeComponent();
        }

        private void MessageForm_FormClosed(object sender, FormClosedEventArgs e)
        {
            this.DialogResult = DialogResult.OK;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.HideMaskAction();
        }
    }