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imagechar

(PHP 4, PHP 5)

imagechar水平地画一个字符

说明

bool imagechar ( resource $image , int $font , int $x , int $y , string $c , int $color )

imagechar() 将字符串 c 的第一个字符画在 image 指定的图像中,其左上角位于 xy(图像左上角为 0, 0),颜色为 color。如果 font 是 1,2,3,4 或 5,则使用内置的字体(更大的数字对应于更大的字体)。

Example #1 imagechar() 例子

<?php

$im 
imagecreate(100,100);

$string 'PHP';

$bg imagecolorallocate($im255255255);
$black imagecolorallocate($im000);

// prints a black "P" in the top left corner
imagechar($im100$string$black);

header('Content-type: image/png');
imagepng($im);

?>

参见 imagecharup()imageloadfont()

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User Contributed Notes 2 notes

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2
liam dot wiltshire at lineone dot net
5 years ago
A quick function to automatically generate a multi line image from a string, with the image size automatically calculated from the string itself.

<?php

function multilineimage($string){

   
// Probably not the best way of handling newlines, but bar OS9, doesn't really cause a problem
   
$string = str_replace("\r","",$string);
   
$string = explode("\n",$string);

   
$maxlen = 0;
    foreach (
$string as $str){
        if (
strlen($str) > $maxlen){
           
$maxlen = strlen($str);
        }
    }

   
// Set font size
   
$font_size = 4;

   
// Create image width dependant on width of the string
   
$width  = imagefontwidth($font_size)*$maxlen;
   
// Set height to that of the font
   
$height = imagefontheight($font_size) * count($string);
   
// Create the image pallette
   
$img = imagecreate($width,$height);
   
// Grey background
   
$bg    = imagecolorallocate($img, 205, 255, 255);
   
// White font color
   
$color = imagecolorallocate($img, 0, 0, 0);

   
$ypos = 0;

    foreach (
$string as $str){

       
$len = strlen($str);
        for(
$i=0;$i<$len;$i++){
           
// Position of the character horizontally
           
$xpos = $i * imagefontwidth($font_size);
           
// Draw character
           
imagechar($img, $font_size, $xpos, $ypos, $str, $color);
           
// Remove character from string
           
$str = substr($str, 1);  
        }
       
$ypos = $ypos + imagefontheight($font_size);  
    }

   
// Return the image
   
header("Content-Type: image/gif");
   
imagegif($img);
   
// Remove image
   
imagedestroy($img);
}

multilineimage("This is an image
This is line 2\nLine 3
Line 4"
);

?>
up
0
sw at profilschmiede dot de
9 years ago
For the sake of completeness, here is an example for imagechar.
The base-image automatically adjusts to the size and the height of the given string. Using the rand()-function the y-position of each char is slightly varied with every loop-run. You can easily rewrite the script to use a randomly generated string - the one given here just serves as an example.

<?php

$string
= '1 2 3 4 5 6 7 8 9 A B C D E F G';
$font_size = 5;
$width=imagefontwidth($font_size)*strlen($string);
$height=imagefontheight($font_size)*2;
$img = imagecreate($width,$height);
$bg = imagecolorallocate($img,225,225,225);
$black = imagecolorallocate($img,0,0,0);
$len=strlen($string);

for(
$i=0;$i<$len;$i++)
{
   
$xpos=$i*imagefontwidth($font_size);
   
$ypos=rand(0,imagefontheight($font_size));
   
imagechar($img,$font_size,$xpos,$ypos,$string,$black);
   
$string = substr($string,1);   
   
}
header("Content-Type: image/gif");
imagegif($img);
imagedestroy($img);
?>
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