解释这一段代码:Server t = new Server(); myControl cc = new myControl(); Thread control = new Thread(cc); control.start();
时间: 2024-02-29 13:55:40 浏览: 106
这段代码创建了一个Server对象并将其分配给变量t,同时创建了一个myControl对象并将其分配给变量cc。接下来,代码创建了一个Thread对象并将其分配给变量control,该Thread对象的构造函数中传递了cc对象。最后,代码调用Thread对象control的start()方法,该方法启动一个新的线程并在该线程上运行cc对象的run()方法。
简而言之,这段代码启动了一个新的线程来运行myControl对象的run()方法,以控制Server对象的行为。
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private void MyControl_MouseMove(object sender, MouseEventArgs e) { if(sender is UIElement uIElement) { if (isDragging) { Point newPoint = e.GetPosition(canvas); double deltaX = newPoint.X - startPoint.X; double deltaY = newPoint.Y - startPoint.Y; Canvas.SetLeft(uIElement, Canvas.GetLeft(uIElement) + deltaX); Canvas.SetTop(uIElement, Canvas.GetTop(uIElement) + deltaY); startPoint = newPoint; } } } private void MyControl_MouseDown(object sender, MouseButtonEventArgs e) { if (sender is UIElement uIElement) { isDragging = true; startPoint = e.GetPosition(canvas); uIElement.CaptureMouse(); } } private void MyControl_MouseUp(object sender, MouseButtonEventArgs e) { if (sender is UIElement uIElement) { isDragging = false; uIElement.ReleaseMouseCapture(); } }令移动的控件不超过Canvas的边界
可以在 `MyControl_MouseMove` 方法中添加一些代码来检查移动的控件是否超过了 `Canvas` 的边界。具体实现方法如下:
```
private void MyControl_MouseMove(object sender, MouseEventArgs e)
{
if (sender is UIElement uIElement)
{
if (isDragging)
{
Point newPoint = e.GetPosition(canvas);
double deltaX = newPoint.X - startPoint.X;
double deltaY = newPoint.Y - startPoint.Y;
// 计算控件新的位置
double newX = Canvas.GetLeft(uIElement) + deltaX;
double newY = Canvas.GetTop(uIElement) + deltaY;
// 检查控件是否超过 Canvas 的边界
if (newX < 0)
{
newX = 0;
}
else if (newX + uIElement.ActualWidth > canvas.ActualWidth)
{
newX = canvas.ActualWidth - uIElement.ActualWidth;
}
if (newY < 0)
{
newY = 0;
}
else if (newY + uIElement.ActualHeight > canvas.ActualHeight)
{
newY = canvas.ActualHeight - uIElement.ActualHeight;
}
Canvas.SetLeft(uIElement, newX);
Canvas.SetTop(uIElement, newY);
startPoint = newPoint;
}
}
}
```
在上述代码中,我们首先计算出控件的新位置 `newX` 和 `newY`,然后通过一些判断来确保控件不超过 `Canvas` 的边界。如果控件超过了边界,则将其位置设置为边界的位置。最后,我们调用 `Canvas.SetLeft` 和 `Canvas.SetTop` 方法来更新控件的位置。
protected override void OnPaint(PaintEventArgs e) { using (Bitmap buffer = new Bitmap(this.Width, this.Height)) { using (Graphics g = Graphics.FromImage(buffer)) { // 在缓存中绘制图像 base.OnPaint(new PaintEventArgs(g, this.ClientRectangle)); } // 将缓存中的图像渲染到控件上 e.Graphics.DrawImage(buffer, 0, 0); } }在C++/CLR 的写法
在C++/CLR中,可以使用以下代码实现同样的功能:
void MyControl::OnPaint(PaintEventArgs^ e)
{
Bitmap^ buffer = gcnew Bitmap(this->Width, this->Height);
Graphics^ g = Graphics::FromImage(buffer);
// 在缓存中绘制图像
this->OnPaint(gcnew PaintEventArgs(g, this->ClientRectangle));
// 将缓存中的图像渲染到控件上
e->Graphics->DrawImage(buffer, 0, 0);
delete g;
delete buffer;
}
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