剪切图片，为什么是空白，第一个解决100分

Question

public Bitmap GetPartOfImage(string bitmapPathAndName, int width, int height, int offsetX, int offsetY)
        {
            Bitmap sourceBitmap = new Bitmap(bitmapPathAndName);
            Bitmap resultBitmap = new Bitmap(width, height);
            using (Graphics g = Graphics.FromImage(resultBitmap))
            {
                Rectangle resultRectangle = new Rectangle(0, 0, Width, height);
                Rectangle sourceRectangle = new Rectangle(0+offsetX, 0+offsetY, Width, height);
                g.DrawImage(sourceBitmap, resultRectangle, sourceRectangle, GraphicsUnit.Pixel);
            }
            return resultBitmap;
        }
http://www.cnblogs.com/NRabbit/archive/2009/07/19/1736174.html以上代码没有问题，但是指定X,Y坐标后剪切的部分其实没有剪切而是空白。。怎么把空白去掉

Answer 1

应该是你传的参数错误。图片截取是offsetX+width  offsetY+heigth 截取的。参数别传错误了。一个x，一个y。然后需要多少它再去加宽家高度

Answer 2

c#裁剪图片(根据鼠标画的矩形裁剪图片)using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using S10806Class;
using System.IO;namespace GetImage
{
    public partial class GetScreenImgForm : Form
    {        /// <summary>
        /// 图像操作类
        /// </summary>
        ImageWork imageWork = new ImageWork();        /// <summary>
        /// 保存截取到的桌面图像
        /// </summary>
        Image screenImg = null;        /// <summary>
        /// 保存用户截取的图像区域
        /// </summary>
        Rectangle imgRect = new Rectangle();        /// <summary>
        /// 窗体的GDI
        /// </summary>
        Graphics g = null;        /// <summary>
        /// 区域边框画笔
        /// </summary>
        Pen pen = new Pen(Color.Black, 1);        /// <summary>
        /// 是否应该绘制区域
        /// </summary>
        bool isDraw = false;        /// <summary>
        /// 用户是否选择了区域
        /// </summary>
        bool isOption = false;
        public GetScreenImgForm()
        {
            InitializeComponent();     //获取当前桌面截图
            screenImg = imageWork.GetScreenImage();            g = this.CreateGraphics();
        }        private void GetScreenImgForm_Load(object sender, EventArgs e)
        {
            this.Size = new Size(screenImg.Width, screenImg.Height);            this.BackgroundImage = screenImg;
        }        private void GetScreenImgForm_MouseUp(object sender, MouseEventArgs e)
        {
            //没有截图并且单击右键 - 关闭本窗体
            if (e.Button == MouseButtons.Right && !this.isOption)
            {
                this.Close();
            }
            //截图了并且单击右键 - 取消此次截图
            else if (e.Button == MouseButtons.Right && this.isOption)
            {
                g.DrawImage(screenImg, new Point(0, 0));
                this.isOption = false;
                return;
            }
            //在截图情况下松开左键，选择区域结束,等待双击截取
            else if (e.Button == MouseButtons.Left && this.isOption && this.isDraw)
            {
                this.isDraw = false;                imgRect.Width = e.X - imgRect.X;   //区域长度                imgRect.Height = e.Y - imgRect.Y;  //区域高度
            }        }        private void GetScreenImgForm_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left) return;            if (this.isOption) return;            imgRect.X = e.X;   //起始X轴            imgRect.Y = e.Y;   //起始Y轴            this.isDraw = true;//允许绘图
        }        private void GetScreenImgForm_MouseMove(object sender, MouseEventArgs e)
        {
            if (isDraw)
            {
                //刷新图像
                g.DrawImage(screenImg, new Point(0, 0));                this.isOption = true;                Point p1 = new Point(imgRect.X, imgRect.Y);
                Point p2 = new Point(e.X, imgRect.Y);
                Point p3 = new Point(imgRect.X, e.Y);
                Point p4 = new Point(e.X, e.Y);                //画四条边框
                g.DrawLine(pen, p1, p2);
                g.DrawLine(pen, p2, p4);
                g.DrawLine(pen, p4, p3);
                g.DrawLine(pen, p3, p1);
            }
            else
            {
                //确定用户的选择区域
                int top = imgRect.Y;
                int down = imgRect.Y + imgRect.Height;
                int left = imgRect.X;
                int right = imgRect.X + imgRect.Width;                //鼠标在选择区域中会变个模样
                if (e.X > left && e.X < right && e.Y > top && e.Y < down)
                {
                    this.Cursor = Cursors.SizeAll;
                }
                else
                {
                    this.Cursor = Cursors.Cross;
                }
            }
        }        private void GetScreenImgForm_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            try
            {
                //用户双击选择区域时.....
                if (this.Cursor == Cursors.SizeAll)
                {
                    Bitmap b = new Bitmap(this.screenImg);                    Bitmap img = b.Clone(this.imgRect, System.Drawing.Imaging.PixelFormat.DontCare);                    SaveFileDialog dlg = new SaveFileDialog();                    dlg.Filter = "(*.jpg)|*.jpg";                    if (dlg.ShowDialog() != DialogResult.OK) return;                    img.Save(dlg.FileName);                    this.Close();
                }
            }
            catch (Exception err)
            {
                MessageBox.Show(err.Message);
            }
        }    }
}

Answer 3

        private void btnSpiltBitmap_Click(object sender, EventArgs e)
        {
            Bitmap bmSplit = SplitBitmap(@"C:\Documents and Settings\Administrator\桌面\备用\饼状图.jpg", 200, 20, 10, 10);
            this.picbShow.Image = bmSplit;
            this.picbShow.BorderStyle = BorderStyle.FixedSingle;
           
        }        public Bitmap SplitBitmap(string PbmPath, int Pwid, int Phei, int PoffsetX, int PoffsetY)
        {
            Bitmap bmSource = new Bitmap(PbmPath);            Bitmap bmNew = new Bitmap(bmSource);
            bmSource.Dispose();
            bmSource = null;            Bitmap bmSplit = new Bitmap(Pwid, Phei);
            Graphics g = Graphics.FromImage(bmSplit);
            g.DrawImage(bmNew, new Rectangle(PoffsetX, PoffsetY, Pwid, Phei));
            g.Dispose();
            g = null;
            bmNew.Dispose();
            bmNew = null;            return bmSplit;
        }
经过测试完全正确.

Answer 4

g.DrawImage(bmNew, new Rectangle(0, 0, Pwid, Phei), new Rectangle(PoffsetX, PoffsetY, Pwid, Phei), System.Drawing.GraphicsUnit.Pixel);
额... 那句话改成这个...