18c03-2.php

介绍PHP5的给类型函数应用

<?php
// Create a blank image to test with.
$gfx = imagecreatetruecolor(200, 200);

// Declare a white background
$white = imagecolorallocate($gfx, 255, 255, 255);

// Make the entire background white
imagefilledrectangle($gfx, 0, 0, 199, 199, $white);

// Now make three alpha colors, each fairly transparent.
$blue = imagecolorallocatealpha($gfx, 0, 0, 255, 100);
$green = imagecolorallocatealpha($gfx, 0, 255, 0, 100);
$red = imagecolorallocatealpha($gfx, 255, 0, 0, 100);

// Draw the circles on the image overlapping:
imagefilledellipse($gfx, 133, 67, 100, 100, $blue);
imagefilledellipse($gfx, 67, 67, 100, 100, $green);
imagefilledellipse($gfx, 100, 133, 100, 100, $red);

// Output our sample as a PNG
header('Content-type: image/png');
imagepng($gfx);
?>