[求助]：求图块插入例程

weekswu

想用ObjectARX实现dwg文件中的图块插入到当前图形中。
不知道如何下手，还请高人指教，最好有例程。

layworld

To create a block table record

Create a new block table record.
Add the block table record to the block table.
Create entities and add them to the block table record.
Create attribute definitions, set their values, and add them to the block table record.
When you close the block table record, the block begin and block end objects are added to the block automatically.

The following example creates a new block table record named
ASDK-BLOCK-WITH-ATTR and adds it to the block table. Next it creates a circle entity and adds it to the new block table record. It creates two attribute definition entities (the second is a clone of the first) and appends them to the same block table record.

void
defineBlockWithAttributes(
    AcDbObjectId& blockId, // This is a returned value.
    const AcGePoint3d& basePoint,
    double textHeight,
    double textAngle)
{
    int retCode = 0;
    AcDbBlockTable *pBlockTable = NULL;
    AcDbBlockTableRecord* pBlockRecord = new AcDbBlockTableRecord;
    AcDbObjectId entityId;
    // Step 1: Set the block name and base point of the
    // block definition.
    //
    pBlockRecord->setName("ASDK-BLOCK-WITH-ATTR");
    pBlockRecord->setOrigin(basePoint);

    // Open the block table for write.
    //
    acdbHostApplicationServices()->workingDatabase()
        ->getSymbolTable(pBlockTable, AcDb::kForWrite);

    // Step 2: Add the block table record to block table.
    //
    pBlockTable->add(blockId, pBlockRecord);

    // Step 3: Create a circle entity.
    //
    AcDbCircle *pCircle = new AcDbCircle;
    pCircle->setCenter(basePoint);
    pCircle->setRadius(textHeight * 4.0);
    pCircle->setColorIndex(3);

    // Append the circle entity to the block record.
    //
    pBlockRecord->appendAcDbEntity(entityId, pCircle);
    pCircle->close();

    // Step 4: Create an attribute definition entity.
    //
    AcDbAttributeDefinition *pAttdef
        = new AcDbAttributeDefinition;

    // Set the attribute definition values.
    //
    pAttdef->setPosition(basePoint);
    pAttdef->setHeight(textHeight);
    pAttdef->setRotation(textAngle);
    pAttdef->setHorizontalMode(AcDb::kTextLeft);
    pAttdef->setVerticalMode(AcDb::kTextBase);
    pAttdef->setPrompt("Prompt");
    pAttdef->setTextString("DEFAULT");
    pAttdef->setTag("Tag");
    pAttdef->setInvisible(Adesk::kFalse);
    pAttdef->setVerifiable(Adesk::kFalse);
    pAttdef->setPreset(Adesk::kFalse);
    pAttdef->setConstant(Adesk::kFalse);
    pAttdef->setFieldLength(25);

    // Append the attribute definition to the block.
    //
    pBlockRecord->appendAcDbEntity(entityId, pAttdef);

    // The second attribute definition is a little easier
    // because we are cloning the first one.
    //
    AcDbAttributeDefinition *pAttdef2
        = AcDbAttributeDefinition::cast(pAttdef->clone());

    // Set the values that are specific to the
    // second attribute definition.
    //
    AcGePoint3d tempPt(basePoint);
    tempPt.y -= pAttdef2->height();
    pAttdef2->setPosition(tempPt);
    pAttdef2->setColorIndex(1); // Red
    pAttdef2->setConstant(Adesk::kTrue);

    // Append the second attribute definition to the block.
    //
    pBlockRecord->appendAcDbEntity(entityId, pAttdef2);
    pAttdef->close();
    pAttdef2->close();
    pBlockRecord->close();
    pBlockTable->close();
    return;
}
To insert a block with attributes into a drawing

Create a block reference entity (AcDbBlockReference).
Call the setBlockTableRecord() function to specify the object ID of the referenced block table record. (The object ID can also be specified directly in the constructor of the block reference.)
Append the block reference to a block table record (model space, paper space, or some other block).
Use a block table record iterator on the referenced block table record, searching for attribute definitions. For each one found, create a new AcDbAttribute entity, fill it in with the attribute definition's data, and then append it to the block reference using the appendAttribute() function.
The following example creates a block reference, fills in the attributes, and appends the reference to the database. It uses global functions to obtain user input. The defineBlockWithAttributes() function shown in the previous section is used to create the block reference. This example uses a block table record iterator to step through the attribute definitions and create a corresponding attribute for each attribute definition. The attribute values are set from the original attribute definition using the setPropertiesFrom() function.

void
addBlockWithAttributes()
{
    // Get an insertion point for the block reference,
    // definition, and attribute definition.
    //
    AcGePoint3d basePoint;
    if (acedGetPoint(NULL, "\nEnter insertion point: ",
        asDblArray(basePoint)) != RTNORM)
        return;

    // Get the rotation angle for the attribute definition.
    //
    double textAngle;
    if (acedGetAngle(asDblArray(basePoint),
        "\nEnter rotation angle: ", &textAngle) != RTNORM)
        return;

    // Define the height used for the attribute definition text.
    //
    double textHeight;
    if (acedGetDist(asDblArray(basePoint),
        "\nEnter text height: ", &textHeight) != RTNORM)
        return;

    // Build the block definition to be inserted.
    //
    AcDbObjectId blockId;
    defineBlockWithAttributes(blockId, basePoint,
        textHeight, textAngle);

    // Step 1: Allocate a block reference object.
    //
    AcDbBlockReference *pBlkRef = new AcDbBlockReference;

    // Step 2: Set up the block reference to the newly
    // created block definition.
    //
    pBlkRef->setBlockTableRecord(blockId);

    // Give it the current UCS normal.
    //
    struct resbuf to, from;
    from.restype = RTSHORT;
    from.resval.rint = 1; // UCS
    to.restype = RTSHORT;
    to.resval.rint = 0; // WCS
    AcGeVector3d normal(0.0, 0.0, 1.0);
    acedTrans(&(normal.x), &from, &to, Adesk::kTrue,
        &(normal.x));

    // Set the insertion point for the block reference.
    //
    pBlkRef->setPosition(basePoint);

    // Indicate the LCS 0.0 angle, not necessarily the UCS 0.0 angle.
    //
    pBlkRef->setRotation(0.0);
    pBlkRef->setNormal(normal);

    // Step 3: Open the current database's model space
    // block Table Record.
    //
    AcDbBlockTable *pBlockTable;
    acdbHostApplicationServices()->workingDatabase()
        ->getSymbolTable(pBlockTable, AcDb::kForRead);
    AcDbBlockTableRecord *pBlockTableRecord;
    pBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord,
        AcDb::kForWrite);
    pBlockTable->close();

    // Append the block reference to the model space
    // block Table Record.
    //
    AcDbObjectId newEntId;
    pBlockTableRecord->appendAcDbEntity(newEntId, pBlkRef);
    pBlockTableRecord->close();

    // Step 4: Open the block definition for read.
    //
    AcDbBlockTableRecord *pBlockDef;
    acdbOpenObject(pBlockDef, blockId, AcDb::kForRead);

    // Set up a block table record iterator to iterate
    // over the attribute definitions.
    //
    AcDbBlockTableRecordIterator *pIterator;
    pBlockDef->newIterator(pIterator);
    AcDbEntity *pEnt;
    AcDbAttributeDefinition *pAttdef;
    for (pIterator->start(); !pIterator->done();
        pIterator->step())
    {
        // Get the next entity.
        //
        pIterator->getEntity(pEnt, AcDb::kForRead);

        // Make sure the entity is an attribute definition
        // and not a constant.
        //
        pAttdef = AcDbAttributeDefinition::cast(pEnt);
        if (pAttdef != NULL && !pAttdef->isConstant()) {
            // We have a non-constant attribute definition,
            // so build an attribute entity.
            //
            AcDbAttribute *pAtt = new AcDbAttribute();
            pAtt->setPropertiesFrom(pAttdef);
            pAtt->setInvisible(pAttdef->isInvisible());

            // Translate the attribute by block reference.
            // To be really correct, the entire block
            // reference transform should be applied here.
            //
            basePoint = pAttdef->position();
            basePoint += pBlkRef->position().asVector();
            pAtt->setPosition(basePoint);
            pAtt->setHeight(pAttdef->height());
            pAtt->setRotation(pAttdef->rotation());
            pAtt->setTag("Tag");
            pAtt->setFieldLength(25);
            char *pStr = pAttdef->tag();
            pAtt->setTag(pStr);
            free(pStr);
            pAtt->setFieldLength(pAttdef->fieldLength());

            // The database column value should be displayed.
            // INSERT prompts for this.
            //
            pAtt->setTextString("Assigned Attribute Value");
            AcDbObjectId attId;
            pBlkRef->appendAttribute(attId, pAtt);
            pAtt->close();
        }
        pEnt->close(); // use pEnt... pAttdef might be NULL
    }
    delete pIterator;
    pBlockDef->close();
    pBlkRef->close();
}

weekswu

2楼楼主，谢谢啦。
另问，如何从dwg文件中读取图块