ArcEngine地图窗口指定区域导出指定DPI多格式---delphi/C#实现
2021-04-13 02:26
标签：rds null 都差不多 truncate device output upper 说明 ram ArcEngine地图窗口指定区域导出指定DPI多格式---delphi/C#实现 标签：rds null 都差不多 truncate device output upper 说明 ram 原文地址：https://www.cnblogs.com/gisoracle/p/8986718.htmldelphi/C#实现，其他语言稍微改下就行了。AE的编码各个语言都差不多，这里也没用到某一语言的特性。
函数特点：
1.可以精确导出指定范围的图形要素
2.支持多格式.TIF， .EMF，.GIF，.PDF，.PNG，.SVG，.AI，.EPS，.jpg等
3.Tif格式导出时支持坐标信息导出，支持压缩格式选择
delphi 版：
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{海龙 created
功能说明：指定地图窗口指定区域裁图
参数说明：
指定地图窗口pMap
指定范围裁图pExtent,如某一图形的envolope或map.extent之类的
输出图片文件名称strPicFile，根据后缀名判断裁出图片类型
输出图片dpi iOutResolution ,默认300
裁图时地图窗口需设置的比例尺 sMapBLC ,可以为空
bGeoTiff 文件类型为tif时有效，为true时保存坐标信息
pTifCompressionType 文件类型为tif时有效，tif的压缩类型，默认无损
}
function ClipMap2Pic(pMap: IMap;pExtent: IEnvelope; strPicFile: String; iOutResolution: Integer = 300; sMapBLC: String = ‘‘;
bGeoTiff : Boolean = False; pTifCompressionType: esriTIFFCompression = esriTIFFCompressionNone):Boolean;
var
pAV: IActiveView;
pEnvNew: IEnvelope;
ptagTmp: tagRECT;
pExport: IExport;
ihdc, iPrevOutputImageQuality: Integer;
dRes: Double;
dWidth, dHeight, dMapBLC: Double;
tmpDC: HDC;
iScreenResolution: Integer;
deviceRECT: tagRECT;
pSD: IScreenDisplay;
pDT: IDisplayTransformation;
sWJLX: string;
//地图距离转屏幕像素数,不同缩放比例尺下同样距离对应像素数不同的，有特殊需要时设置sMapBLC
function ConvertMapUnitsToPixels(pAV: IActiveView;dMapUnits: Double):double;
var
pBounds: IEnvelope;
pDeviceFrame: tagRECT;
iDeviceRight, iDeviceLeft, iPixelExtent: integer;
dRealWorldExtent, dSizeOfEachPixel: double;
begin
Result:= 600;
pDT.Get_DeviceFrame(pDeviceFrame);
iDeviceLeft:= pDeviceFrame.left;
iDeviceRight:= pDeviceFrame.right;
iPixelExtent:= iDeviceRight-iDeviceLeft;
pDT.Get_VisibleBounds(pBounds);
pBounds.Get_Width(dRealWorldExtent);
dSizeOfEachPixel:= dRealWorldExtent / iPixelExtent;
Result:= dMapUnits/dSizeOfEachPixel ;
end;
begin
Result:= False;
if pMap = nil then Exit;
if strPicFile = ‘‘ then Exit;
try
if FileExists(strPicFile) then
DeleteFile(PChar(strPicFile));
if (sMapBLC ‘‘) and TryStrToFloat(sMapBLC, dMapBLC) and (dMapBLC > 0) then
pMap.Set_MapScale(StrToFloatEx(sMapBLC));//map的比例尺调整为出图比例尺
pAV:= pMap as IActiveView;
sWJLX := UpperCase(RightStr(strPicFile, 4));
if sWJLX = ‘.TIF‘ then //根据文件名后4位判断输出类型
pExport := CoExportTiff.Create as IExport
else
if sWJLX = ‘.EMF‘ then
pExport := CoExportEMF.Create as IExport
else
if sWJLX = ‘.BMP‘ then
pExport := CoExportBMP.Create as IExport
else
if sWJLX = ‘.GIF‘ then
pExport := CoExportGIF.Create as IExport
else
if sWJLX = ‘.PDF‘ then
pExport := CoExportPDF.Create as IExport
else
if sWJLX = ‘.PNG‘ then
pExport := CoExportPNG.Create as IExport
else
if sWJLX = ‘.SVG‘ then
pExport := CoExportEMF.Create as IExport
else
if RightStr(sWJLX, 3) = ‘.AI‘ then
pExport := CoExportAI.Create as IExport
else
if sWJLX = ‘.EPS‘ then
pExport := CoExportPS.Create as IExport
else
pExport := CoExportJPEG.Create as IExport;
pAV.Get_ScreenDisplay(pSD);
pSD.Get_DisplayTransformation(pDT);
(pDT as IOutputRasterSettings).Get_ResampleRatio(iPrevOutputImageQuality);
tmpDC:= GetDC(0);
iScreenResolution:= GetDeviceCaps(tmpDC, 88); //获取屏幕dpi
ReleaseDC(0, tmpDC);
// 根据传入的pExtent确定裁图的画布大小（出图比例尺下裁图范围的像素高和宽）
pExtent.Get_Width(dWidth);
pExtent.Get_Height(dHeight);
ptagTmp.left := 0; //ptagTmp的right和bottom非常主要
ptagTmp.top := 0;
ptagTmp.right := trunc(ConvertMapUnitsToPixels(pAV,dWidth) * iOutResolution / iScreenResolution); //把地图距离转为屏幕像素个数
ptagTmp.bottom := trunc(ConvertMapUnitsToPixels(pAV,dHeight) * iOutResolution / iScreenResolution);
pEnvNew:= CoEnvelope.Create as IEnvelope;
pEnvNew.PutCoords(ptagTmp.left,ptagTmp.top,ptagTmp.right,ptagTmp.bottom); //裁图的画布大小
pExport.Set_ExportFileName(strPicFile);
pExport.Set_Resolution(iOutResolution);
pExport.Set_PixelBounds(pEnvNew);
if sWJLX = ‘.TIF‘ then
begin
if bGeoTiff then
begin
(pExport as IExportTIFF).Set_GeoTiff(True);//包含tif文件坐标信息，这2句是必须的
(pExport as IWorldFileSettings).Set_MapExtent(pExtent);
end;
(pExport as IExportTIFF).Set_CompressionType(pTifCompressionType);
end;
if sWJLX = ‘.PDF‘ then
begin
(pExport as IExportPDF).Set_Compressed(True);
(pExport as IExportPDF).Set_EmbedFonts(True);
(pExport as IExportPDF).Set_ImageCompression(esriExportImageCompressionNone);
end;
pExport.StartExporting(ihdc);
pAV.Output(ihdc, iOutResolution, ptagTmp, pExtent, nil);
pExport.FinishExporting;
pExport.Cleanup;
(pDT as IOutputRasterSettings).Set_ResampleRatio(iPrevOutputImageQuality);
if FileExists(strPicFile) then
Result:= True;
except
Result:= False;
end;
end;
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Ｃ＃版本：
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/* GDI delegate to GetDeviceCaps function */
[DllImport("GDI32.dll")]
public static extern int GetDeviceCaps(int hdc, int nIndex);
/* User32 delegates to getDC and ReleaseDC */
[DllImport("User32.dll")]
public static extern int GetDC(int hWnd);
[DllImport("User32.dll")]
public static extern int ReleaseDC(int hWnd, int hDC);
[DllImport("user32.dll", SetLastError = true)]
static extern bool SystemParametersInfo(uint uiAction, uint uiParam, ref int pvParam, uint fWinIni);
///
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文章标题：ArcEngine地图窗口指定区域导出指定DPI多格式---delphi/C#实现
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