如何在PictureBox中平移图像

我有一个自定义PictureBox ，可以使用MouseWheel事件放大。 现在我想为它添加一个平移function。 我的意思是当PictureBox处于缩放状态时，如果用户点击并保持点击然后移动鼠标，图像将在图片框内平移。

这是我的代码，但不幸的是它不起作用！ 我不知道在哪里看…

 private Point _panStartingPoint = Point.Empty; private bool _panIsActive; private void CurveBox_MouseDown(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { Focus(); _panIsActive = true; _panStartingPoint = e.Location; } } private void CurveBox_MouseUp(object sender, MouseEventArgs e) { _panIsActive = false; } private void CurveBox_MouseLeave(object sender, EventArgs e) { _panIsActive = false; } private void CurveBox_MouseMove(object sender, MouseEventArgs e) { if(_panIsActive && IsZoomed) { var g = CreateGraphics(); //Create graphics from PictureBox var nx = _panStartingPoint.X + eX; var ny = _panStartingPoint.Y + eY; var sourceRectangle = new Rectangle(nx, ny, Image.Width, Image.Height); g.DrawImage(Image, nx, ny, sourceRectangle, GraphicsUnit.Pixel); } } 

我怀疑MouseMove事件……我不确定此事件中是否发生任何事情和/或nx和ny确实包含正确的点。

任何帮助/提示都非常适合！

Answer 1

我认为数学是倒退的。 试试这样：

 private Point startingPoint = Point.Empty; private Point movingPoint = Point.Empty; private bool panning = false; void pictureBox1_MouseDown(object sender, MouseEventArgs e) { panning = true; startingPoint = new Point(e.Location.X - movingPoint.X, e.Location.Y - movingPoint.Y); } void pictureBox1_MouseUp(object sender, MouseEventArgs e) { panning = false; } void pictureBox1_MouseMove(object sender, MouseEventArgs e) { if (panning) { movingPoint = new Point(e.Location.X - startingPoint.X, e.Location.Y - startingPoint.Y); pictureBox1.Invalidate(); } } void pictureBox1_Paint(object sender, PaintEventArgs e) { e.Graphics.Clear(Color.White); e.Graphics.DrawImage(Image, movingPoint); } 

你没有处理你的图形对象，CreateGraphics只是一个临时绘图（最小化会擦除它）所以我将绘图代码移动到Paint事件，并且只是在用户平移时失效。