Winform 图片鼠标滚动查看(放大,缩小,旋转,拖动查看)[日常随笔]

方法千千万,我只是其中一笔[通过控制PictureBox来控制图片,图片完全施展在控件中]...几久不做,还真有点陌生!

窗体构造中添加鼠标滚动:

/// <summary>
        /// 窗体构造方法
        /// </summary>
        public CandidateForm()
        {
            InitializeComponent();
            this.MouseWheel += new MouseEventHandler(CandidateForm_MouseWheel);
        }

滚动监听:并且保持图片正中

/// <summary>
        /// 鼠标滚动
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void CandidateForm_MouseWheel(object sender, MouseEventArgs e)
        {
            this.pic.Dock = DockStyle.None;
            this.pic.BorderStyle = BorderStyle.FixedSingle;
            Size size = this.pic.Size;
            size.Width += e.Delta;
            if (size.Width > pic.Image.Width)
            {
                pic.Width = pic.Image.Width;
                pic.Height = pic.Image.Height;
            }
            else if (size.Width * pic.Image.Height / pic.Image.Width < pic.Parent.Height - 200)
            {
                return;
            }
            else
            {
                pic.Width = size.Width;
                pic.Height = size.Width * pic.Image.Height / pic.Image.Width;
            }
            pic.Left = (pic.Parent.Width - pic.Width) / 2;
            pic.Top = (pic.Parent.Height - pic.Height) / 2;
        }

旋转:

private void 左旋ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (basicBt != null)
            {
                basicBt = Tools.Rotate(basicBt, 90);
                height = this.pic.Width;
                width = this.pic.Height;
                setBasicPb(basicBt);
            }
        }

        private void 右旋ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (basicBt != null)
            {
                basicBt = Tools.Rotate(basicBt, 270);
                height = this.pic.Width;
                width = this.pic.Height;
                setBasicPb(basicBt);
            }
        }

拖动直接在鼠标点击事件中,对PictureBox位置根据鼠标拖动进行处理就好.关键代码:

//拖动
            if (canDrag)
            {
               pic.Location =
                    new Point(pic.Left + e.X - p0.X, pic.Top + e.Y - p0.Y);
            }

如果不是特意做图片查看,一般还会有对图片进行处理的功能,及需要用到鼠标拖动啊,针对原图片的定位等等~~ 则要用到图片的相对位置定位.

因为使用的是通过改变PictureBox的方法进行处理,所以只需算出比例即可.

   rate = (double)pic.Width / (double)pic.Image.Width;