自定义控件检查是否已启动调整大小
自定义控件检查是否已启动调整大小
提问于 2015-06-01 13:57:38
我创建了一个名为Control的自定义Ellipse。我可以调整大小，移动，并画这个Ellipse。现在，我正在尝试为调整大小添加撤销/重做功能。用户可以在右下角调整控件的大小。此时，只要光标位于Control的右下角，控件就会打印hello。但是我想要的是，当用户开始调整大小时(所以左键向下，光标在右下角)，hello就会被打印出来(只有一次)。如何做到这一点，还是有另一种(更好的)方式来做它？
Ellipse.cs
class Ellipse : Control
{
private Point mDown { get; set; }
public Ellipse()
{
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
this.BackColor = Color.Transparent;
this.DoubleBuffered = true;
this.ResizeRedraw = true;
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
// Draw a black ellipse in the rectangle represented by the control.
e.Graphics.FillEllipse(Brushes.Black, 0, 0, Width, Height);
}
protected override void OnMouseDown(MouseEventArgs e)
{
base.OnMouseDown(e);
mDown = e.Location;
}
protected override void OnMouseMove(MouseEventArgs e)
{
// Call MyBase.OnMouseMove to activate the delegate.
base.OnMouseMove(e);
if (e.Button == MouseButtons.Left)
{
Location = new Point(e.X + Left - mDown.X, e.Y + Top - mDown.Y);
}
}
/* Allow resizing at the bottom right corner */
protected override void WndProc(ref Message m)
{
const int wmNcHitTest = 0x84;
const int htBottomLeft = 16;
const int htBottomRight = 17;
if (m.Msg == wmNcHitTest)
{
Console.WriteLine("Hello");
int x = (int)(m.LParam.ToInt64() & 0xFFFF);
int y = (int)((m.LParam.ToInt64() & 0xFFFF0000) >> 16);
Point pt = PointToClient(new Point(x, y));
Size clientSize = ClientSize;
if (pt.X >= clientSize.Width - 16 && pt.Y >= clientSize.Height - 16 && clientSize.Height >= 16)
{
m.Result = (IntPtr)(IsMirrored ? htBottomLeft : htBottomRight);
return;
}
}
base.WndProc(ref m);
} 回答 1
Stack Overflow用户
回答已采纳
发布于 2015-06-01 16:04:48
我会尝试再添加几条消息，以检查鼠标是否在非客户端区域下降，然后再添加另一条消息，以检查大小调整完成后是否完成事务：
private bool userResizing = false;
protected override void WndProc(ref Message m) {
const int wmNcHitTest = 0x84;
const int htBottomLeft = 16;
const int htBottomRight = 17;
const int WM_EXITSIZEMOVE = 0x232;
const int WM_NCLBUTTONDWN = 0xA1;
if (m.Msg == WM_NCLBUTTONDWN) {
if (!userResizing) {
userResizing = true;
Console.WriteLine("Start Resizing");
}
} else if (m.Msg == WM_EXITSIZEMOVE) {
if (userResizing) {
userResizing = false;
Console.WriteLine("Finish Resizing");
}
} else if (m.Msg == wmNcHitTest) {
int x = (int)(m.LParam.ToInt64() & 0xFFFF);
int y = (int)((m.LParam.ToInt64() & 0xFFFF0000) >> 16);
Point pt = PointToClient(new Point(x, y));
Size clientSize = ClientSize;
if (pt.X >= clientSize.Width - 16 &&
pt.Y >= clientSize.Height - 16 &&
clientSize.Height >= 16) {
m.Result = (IntPtr)(IsMirrored ? htBottomLeft : htBottomRight);
return;
}
}
base.WndProc(ref m);
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/30575472
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