(TBarcodeFmx2D_PDF417)
For a PDF417 barcode symbol, the property specifies whether to use the remaining capacity to automatically upgrade the error correction code level in order to increase symbols strength.
property ECCLevelUpgrade: Boolean;
For a PDF417 barcode symbol, the symbol size may be determined depending on the barcode text length and the error correction code level specified by the ECCLevel property. And the barcode text and the error correction code don't usually fill the maximum data capacity of the symbol. the property specifies whether to use the remaining capacity to automatically upgrade the error correction code level, in order to increase symbols strength.
If the ECCLevelUpgrade property is set to true, the highest error correction code level that can be accommodated by current symbol size will by used for creating more robust symbols. Note, the new level is always no lower than the level specified by the ECCLevel property, and the symbol size will not be increased.
If the ECCLevelUpgrade property is set to false, the error correction code level specified by the ECCLevel property will be used always. If the ECCLevel property is set to one of values from elECC_0 to elECC_8, the factual error correction code level is always equal to the value of the ECCLevel property. If the ECCLevel property is set to elEcc_Auto, the factual error correction code level is the recommended minimum ECC level, depending on the length of barcode text.
The CurrentECCLevel property can be used to get the factual error correction code level.
See also the "Error checking and correcting (ECC)" section in the "TBarcodeFmx2D_PDF417" article.