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我從http://support.microsoft.com/kb/314945得到了代碼來繪製一個可逆/橡皮筋矩形。我向它添加了代碼,這樣當我離開鼠標左鍵時,圖像上也會創建一個矩形,然後用它來剪裁圖像。繪製可逆矩形
此作品非常棒。唯一的問題是,橡皮圈的矩形不會從鼠標所在的位置開始或結束......這種差異很小,但仍然非常值得注意。之後我使用相同的合作伙伴繪製矩形,這正是我的鼠標開始和結束的地方。幫助將不勝感激。
這裏是代碼:(已修復問題 - 添加代碼,其他人可以從中受益) 我已經使它成爲控件,我在任何需要它的地方使用它!
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace CroppingControl
{
public partial class CroppingImage : UserControl
{
Rectangle rc = new Rectangle();
Boolean bHaveMouse;
Point ptOriginal = new Point();
Point ptLast = new Point();
Image Pic;
public CroppingImage()
{
InitializeComponent();
pictureBox1.MouseDown += new MouseEventHandler(MyMouseDown);
pictureBox1.MouseUp += new MouseEventHandler(MyMouseUp);
pictureBox1.MouseMove += new MouseEventHandler(MyMouseMove);
bHaveMouse = false;
}
public Image Image
{
set
{
pictureBox1.Image = value;
Pic = value;
}
get
{
return pictureBox1.Image;
}
}
public void MyMouseDown(Object sender, MouseEventArgs e)
{
pictureBox1.Image = Pic;
// Make a note that we "have the mouse".
bHaveMouse = true;
// Store the "starting point" for this rubber-band rectangle.
ptOriginal.X = e.X;
ptOriginal.Y = e.Y;
// Special value lets us know that no previous
// rectangle needs to be erased.
ptLast.X = -1;
ptLast.Y = -1;
}
// Convert and normalize the points and draw the reversible frame.
private void MyDrawReversibleRectangle(Point p1, Point p2)
{
Point px = p1;
Point py = p2;
// Convert the points to screen coordinates.
p1 = PointToScreen(p1);
p2 = PointToScreen(p2);
// Normalize the rectangle.
if (p1.X < p2.X)
{
rc.X = p1.X;
rc.Width = p2.X - p1.X;
}
else
{
rc.X = p2.X;
rc.Width = p1.X - p2.X;
}
if (p1.Y < p2.Y)
{
rc.Y = p1.Y;
rc.Height = p2.Y - p1.Y;
}
else
{
rc.Y = p2.Y;
rc.Height = p1.Y - p2.Y;
}
// Draw the reversible frame.
ControlPaint.DrawReversibleFrame(rc, Color.Black, FrameStyle.Dashed);
rc.X = px.X;
rc.Y = px.Y;
}
// Called when the left mouse button is released.
public void MyMouseUp(Object sender, MouseEventArgs e)
{
// Set internal flag to know we no longer "have the mouse".
bHaveMouse = false;
// If we have drawn previously, draw again in that spot
// to remove the lines.
if (ptLast.X != -1)
{
Point ptCurrent = new Point(e.X, e.Y);
MyDrawReversibleRectangle(ptOriginal, ptLast);
Graphics graphics = pictureBox1.CreateGraphics();
Pen pen = new Pen(Color.Gray, 2);
pen.DashStyle = System.Drawing.Drawing2D.DashStyle.DashDot;
graphics.DrawRectangle(pen, rc);
}
// Set flags to know that there is no "previous" line to reverse.
ptLast.X = -1;
ptLast.Y = -1;
ptOriginal.X = -1;
ptOriginal.Y = -1;
}
// Called when the mouse is moved.
public void MyMouseMove(Object sender, MouseEventArgs e)
{
Point ptCurrent = new Point(e.X, e.Y);
// If we "have the mouse", then we draw our lines.
if (bHaveMouse)
{
// If we have drawn previously, draw again in
// that spot to remove the lines.
if (ptLast.X != -1)
{
MyDrawReversibleRectangle(ptOriginal, ptLast);
}
// Update last point.
ptLast = ptCurrent;
// Draw new lines.
MyDrawReversibleRectangle(ptOriginal, ptCurrent);
}
}
}
}
您可以添加一些代碼嗎?你是如何獲得鼠標座標的,你如何使用這些座標? – 2011-02-04 08:33:16
做了示例代碼工作沒有什麼差別?如果是這樣 - 請發佈您的代碼 - 這樣可以看到差異發生的位置。 – Gambrinus 2011-02-04 08:42:49