如何:使用PicturBox實(shí)現(xiàn)類似淘寶的局部放大功選自： 概要：本文將講述如何使用PictureBox控件實(shí)現(xiàn)的局部放大瀏覽功能，效果類似淘寶網(wǎng)Winform的環(huán)境下實(shí)現(xiàn)（當(dāng)時(shí)開發(fā)的系統(tǒng)用的是winform，但是代碼實(shí)現(xiàn)思路在其他環(huán)境（如WPF）應(yīng)該是通用的。當(dāng)然這個(gè)是在淘寶首頁(yè)上隨便選的一張（呵呵，不含任何宣傳的成分。不管這個(gè)功能 第一步：布局按照上面的布局方式，在Form中放入三個(gè)PictureBox控件，ID分別為：picBox、picBoxOriginal：是實(shí)際的尺寸，在這里是為了對(duì)比效果。找的一張200×200px的即開始運(yùn)行是不顯示picBox_Show。為picBox和picBoxOriginal選擇一張（Image屬性，注：兩個(gè)是同一張第二步：鼠標(biāo)對(duì)picBox三個(gè)：鼠標(biāo)移動(dòng)MouseMoveve、鼠標(biāo)離開MouseLeave、Paint。只因?yàn)橐婚_始自動(dòng)生成用的是默認(rèn)的ID（ctrBx1，后來(lái)為了正規(guī)點(diǎn)就換了個(gè)ID，這里就privatevoidpictureBox1_Paint(objectsender,PaintEventArgs{}Paint中處理邏輯：當(dāng)鼠標(biāo)移動(dòng)在的某個(gè)位置時(shí)，我們需要繪個(gè)長(zhǎng)方形區(qū)域，同時(shí)顯示局部放大（picBox_Show。當(dāng)執(zhí)行picBox.Refresh()方法時(shí)將觸發(fā)該。privatevoidpictureBox1_MouseMove(objectsender,MouseEventArgs{picBox.Focus();//否則滾輪無(wú)isMove=true;movedPoint_X=e.X;movedPoint_Y=e.Y;}在鼠標(biāo)移動(dòng)中，我們需要記錄當(dāng)前鼠標(biāo)點(diǎn)的位置，有全局變量movedPoint_X,movedPoint_YintmovedPoint_X,同時(shí)我們需要設(shè)置一個(gè)鼠標(biāo)移動(dòng)狀態(tài)isMove量[boolisMovefalse;]，標(biāo)識(shí)是否需要重新privatevoidpictureBox1_MouseLeave(objectsender,EventArgs{picBox_Show.Visible=false;picBox_Show.Width=picBox_Show.Height=}鼠標(biāo)移開后，局部顯示(picBox_Show)隱藏，picBox繪制的長(zhǎng)方形也要去掉，最簡(jiǎn)單的就是調(diào)voidpicBox_Show_MouseWheel(objectsender,MouseEventArgs{doublescale=if(picBox_Show.Height>{scale=(double)picBox_Show.Width/}picBox_Show.Width+=(int)(e.Delta*scale);picBox_Show.Height+=e.Delta;}+=第三步：區(qū)域定位更簡(jiǎn)單的陰影畫筆畫網(wǎng)格（FillRectangle方法）呢?等一下我會(huì)講到。畫矩形的原理如上圖所示，AmovedPoint_X=e.X;movedPoint_Y=PenpennewPen(Color.FromArgb(91,98,114畫筆顏_yint_x=movedPoint_X-rect_W/2;int_y=movedPoint_Y-_x=_x<0?0:_y=_y<0?0:_x_xpicBox.Width-rect_WpicBox.Width-rect_W-3_x;3px的目的就_y_ypicBox.Height-rect_HpicBox.Height-rect_H-3:_y;Rectanglerect=newRectangle(_x,_y,rect_W,rect_H);g.DrawRectangle(penrect);//其中Graphicsge.Graphics;//網(wǎng)格邊長(zhǎng)：5pxconstintgridSize=introwGridCount=rect_H/gridSize;intcolumnGridCount=rect_W/gridSize;intx1,x2,y1,y2;x1=x2=_x;y1=y2=x2+=for(inti=1;i<rowGridCount;{y1+=gridSize;y2+=g.DrawLine(pen,x1,y1,x2,}x1=x2=_x;y1=y2=_y;y2+=for(intj=1;j<columnGridCount;{x1+=gridSize;x2+=g.DrawLine(pen,x1,y1,x2,}Bitmapbmp=doublerate_W=Convert.ToDouble(bmp.Width)/picBox.Width;doublerate_H=Convert.ToDouble(bmp.Height)/picBox.Height;所以我們看到的picBox大小可能是經(jīng)過(guò)了縮放的。所以不要錯(cuò)誤地認(rèn)為Bitmapbmp2=bmp.Clone(newRectangle(Convert.ToInt32(rate_W*_x),Convert.ToInt32(rate_H*_y),Convert.ToInt32(rate_W*rect_W),Convert.ToInt32(rate_H*rect_H)),picBox_Show.Image=picBox_Show.SizeMode=PictureBoxSizeMode.Zoom;picBox_Show.Visible=true;if(picBox_Show.Image!={}畫網(wǎng)格為什么避簡(jiǎn)求難？為什么不直接使用更簡(jiǎn)單的陰影畫筆畫網(wǎng)格（FillRectangle方法）呢?附完整代碼public{picBox.MouseWheel+=new}voidpicBox_Show_MouseWheel(objectsender,MouseEventArgs{doublescale=if(picBox_Show.Height>{scale=(double)picBox_Show.Width/}picBox_Show.Width+=(int)(e.Delta*scale);picBox_Show.Height+=e.Delta;}boolisMove=intmovedPoint_X,Penpen=newPen(Color.FromArgb(91,98,HatchBrushbrushnewHatchBrush(HatchStyle.CrossColor.FromArgb(91,98,114),Color.Empty);//使用陰影畫筆畫網(wǎng)格constintrect_W80;constintrect_H=//網(wǎng)格邊長(zhǎng)：5pxconstintgridSize=introwGridCount=rect_H/gridSize;intcolumnGridCount=rect_W/gridSize;privatevoidpictureBox1_Paint(objectsender,PaintEventArgs{if(isMove=={Graphicsg=int_x=movedPoint_X-rect_W/2;int_y=movedPoint_Y-_x=_x<0?0:_y=_y<0?0:_x_xpicBox.Width-rect_WpicBox.Width-rect_W-3_x;3px的目的就_y=_y>=picBox.Height-rect_H?picBox.Height-rect_H-3:_y;Rectanglerect=newRectangle(_x,_y,rect_W,rect_H);g.DrawRectangle(pen,rect);//g.FillRectangle(brush,///*填充網(wǎng)格intx1,x2,y1,y2;x1=x2=_x;y1=y2=_y;x2+=for(inti=1;i<rowGridCount;{y1+=gridSize;y2+=g.DrawLine(pen,x1,y1,x2,}x1=x2=_x;y1=y2=_y;y2+=for(intj=1;j<columnGridCount;{x1+=gridSize;x2+=g.DrawLine(pen,x1,y1,x2,}/*裁剪if(picBox_Show.Image!={}Bitmapbmp=doublerate_W=Convert.ToDouble(bmp.Width)/picBox.Width;doublerate_H=Convert.ToDouble(bmp.Height)/picBox.Height;Bitmapbmp2=bmp.Clone(newRectangle(Convert.ToInt32(rate_W*_x),Convert.ToInt32(rate_H*_y),Convert.ToInt32(rate_W*rect_W),Convert.ToInt32(rate_H*rect_H)),picBox_Show.Image=picBox_Show.SizeMode=PictureBoxSizeMode.Zoom;picBox_Show.Visible=true;isMove=}}privatevoidpictureBox1_Mo