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(PECL imagick 2.0.0)
Imagick::setIteratorIndex — Set the iterator position
$index
)Set the iterator to the position in the image list specified with the index parameter. 此方法在Imagick基于ImageMagick 6.2.9以上版本编译时可用。
index
The position to set the iterator to
成功时返回 TRUE
。
Example #1 Using Imagick::setIteratorIndex() :
Create images, set and get the iterator index
<?php
$im = new Imagick ();
$im -> newImage ( 100 , 100 , new ImagickPixel ( "red" ));
$im -> newImage ( 100 , 100 , new ImagickPixel ( "green" ));
$im -> newImage ( 100 , 100 , new ImagickPixel ( "blue" ));
$im -> setIteratorIndex ( 1 );
echo $im -> getIteratorIndex ();
?>
[#1] wilcobeekhuizen at gmail dot com [2011-03-14 10:06:11]
This function returns true on success but setting the iterator to an invalid index throws an exception instead of returning false:
Fatal error: Uncaught exception 'ImagickException' with message 'Unable to set iterator index'
This can happen when counting images inside a gif file, because the iterator count starts at zero and not one. If you count the number of images in a gif file be sure to use iterator 0 for the first image, like this:
<?php
$image = new Imagick('simple.gif');
$image->setIteratorIndex(0);
?>