php教程

php手册

imagestring

(PHP 4, PHP 5, PHP 7)

imagestring — 水平地画一行字符串

说明

imagestring ( resource $image , int $font , int $x , int $y , string $s , int $col ) : bool

imagestring() 用 col 颜色将字符串 s 画到 image 所代表的图像的 x，y 坐标处（这是字符串左上角坐标，整幅图像的左上角为 0，0）。如果 font 是 1，2，3，4 或 5，则使用内置字体。

Example #1 imagestring() 例子


<?php
// 建立一幅 100X30 的图像
$im = imagecreate(100, 30);

// 白色背景和蓝色文本
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);

// 把字符串写在图像左上角
imagestring($im, 5, 0, 0, "Hello world!", $textcolor);

// 输出图像
header("Content-type: image/png");
imagepng($im);
?>

参见 imageloadfont() 和 imagettftext()。

User Contributed Notes

wheberson dot com dot br at gmail dot com 02-May-2019 05:55


// Convert e-mail to image (png)

function convertEmailToImg ($aValue, $aRed, $aGreen, $aBlue, $aAlphaF=0, $aAlphaB=127, $aFontSize=4)



{

    $img= imagecreatetruecolor (imagefontwidth ($aFontSize) * strlen ($aValue), imagefontheight ($aFontSize));

    imagesavealpha ($img, true);

    imagefill ($img, 0, 0, imagecolorallocatealpha ($img, 0, 0, 0, $aAlphaB));

    imagestring ($img, $aFontSize, 0, 0, $aValue, imagecolorallocatealpha ($img, $aRed, $aGreen, $aBlue, $aAlphaF));

    ob_start ();

    imagepng ($img);

    imagedestroy ($img);

    return base64_encode (ob_get_clean ());

}



// Example

$imgString= convertEmailToImg ('contact@example.com', 0, 0, 255, 0, 127, 4);

Booteille 14-Jan-2015 12:56


Here is a function with similar declaration of imagestring() but who handles whitespaces (It creates new lines and 4 spaces instead of \n and \t) and image's size limits



<?php



/**

 * @author Booteille

 *

 * @param resource $image

 * @param int $font

 * @param int $x

 * @param int $y

 * @param string $string

 * @param int $color

 */

function whitespaces_imagestring($image, $font, $x, $y, $string, $color) {

    $font_height = imagefontheight($font);

    $font_width = imagefontwidth($font);

    $image_height = imagesy($image);

    $image_width = imagesx($image);

    $max_characters = (int) ($image_width - $x) / $font_width ;

    $next_offset_y = $y;



    for($i = 0, $exploded_string = explode("\n", $string), $i_count = count($exploded_string); $i < $i_count; $i++) {

        $exploded_wrapped_string = explode("\n", wordwrap(str_replace("\t", "    ", $exploded_string[$i]), $max_characters, "\n"));

        $j_count = count($exploded_wrapped_string);

        for($j = 0; $j < $j_count; $j++) {

            imagestring($image, $font, $x, $next_offset_y, $exploded_wrapped_string[$j], $color);

            $next_offset_y += $font_height;



            if($next_offset_y >= $image_height - $y) {

                return;

            }

        }

    }

}



?>

jordanslost at gmail 04-Sep-2009 04:52


Here is a small bit I made for writing to a image from right to left when you are limited to imagestring()



<?php



        $pageview_letters = preg_split('//', $string, -1 ); // Form are original array of letters.

        $minus = 6; // The letter spacing in pixels

        $first = true; // Whether or not we have started the string

        $x = 375; // X Location of imagestring

        $y = 23; // Y Location of imagestring

        $letters = array(); // Initiate the array o letters.



        foreach ( $pageview_letters as $letter ) {

        

            $letters[] = $letter;

            

        }

        

        $letters = array_reverse( $letters );

        

        foreach ( $letters as $letter ) {

        

            if ( $first ) {

            

                imagestring( $image, 2, $x, $y, $letter, $light_blue );

                $first = false;

                

            } else {

                

                $x = ( $x - $minus );

                imagestring( $image, 2, $x, $y, $letter, $light_blue );

                

            }

        

        }

?>

eric dot brison at anakeen dot com 24-Apr-2009 12:51


Same function as above but it can display multi-line strings.

<?php

function sendimagetext($text) {

  // Set font size

  $font_size = 4;



  $ts=explode("\n",$text);

  $width=0;

  foreach ($ts as $k=>$string) { //compute width

    $width=max($width,strlen($string));

  }



  // Create image width dependant on width of the string

  $width  = imagefontwidth($font_size)*$width;

  // Set height to that of the font

  $height = imagefontheight($font_size)*count($ts);

  $el=imagefontheight($font_size);

  $em=imagefontwidth($font_size);

  // Create the image pallette

  $img = imagecreatetruecolor($width,$height);

  // Dark red background

  $bg = imagecolorallocate($img, 0xAA, 0x00, 0x00);

  imagefilledrectangle($img, 0, 0,$width ,$height , $bg);

  // White font color

  $color = imagecolorallocate($img, 255, 255, 255);



  foreach ($ts as $k=>$string) {

    // Length of the string

    $len = strlen($string);

    // Y-coordinate of character, X changes, Y is static

    $ypos = 0;

    // Loop through the string

    for($i=0;$i<$len;$i++){

      // Position of the character horizontally

      $xpos = $i * $em;

      $ypos = $k * $el;

      // Draw character

      imagechar($img, $font_size, $xpos, $ypos, $string, $color);

      // Remove character from string

      $string = substr($string, 1);      

    }

  }

  // Return the image

  header("Content-Type: image/png");

  imagepng($img);

  // Remove image

  imagedestroy($img);

}

?>

mike at mike-griffiths dot co dot uk 19-Dec-2008 12:07


I created an alternative using the function imagechar to create a string of an image.  The below function below was used to create an image the same height and width of the text string.  It is used on my website to mask users email addresses.





<?PHP





// Set your string somehow


$string = 'your@example.com';





// Set font size


$font_size = 4;





// Create image width dependant on width of the string


$width  = imagefontwidth($font_size)*strlen($string);


// Set height to that of the font


$height = imagefontheight($font_size);


// Create the image pallette


$img = imagecreate($width,$height);


// Grey background


$bg    = imagecolorallocate($img, 25, 25, 25);


// White font color


$color = imagecolorallocate($img, 255, 255, 255);


// Length of the string


$len = strlen($string);


// Y-coordinate of character, X changes, Y is static


$ypos = 0;


// Loop through the string


for($i=0;$i<$len;$i++){


    // Position of the character horizontally


    $xpos = $i * imagefontwidth($font_size);


    // Draw character


    imagechar($img, $font_size, $xpos, $ypos, $string, $color);


    // Remove character from string


    $string = substr($string, 1);    


    


}


// Return the image


header("Content-Type: image/gif");


imagegif($img);


// Remove image 


imagedestroy($img);





?>

keksnicoh at googlemail dot com 02-Nov-2008 10:42


Some fun with imagestring:



This function is a product of too much time..

It opens an image and create a new image with one letter instead of a pixel.



<?php

error_reporting(E_ALL);

/**

 * generates a image with chars instead of pixels

 *

 * @param string $url Filepath or url

 * @param string $chars The chars which should replace the pixels

 * @param int $shrpns Sharpness (2 = every second pixel, 1 = every pixel ... )

 * @param int $size 

 * @param int $weight font-weight/size

 * @return sesource

 * @author Nicolas 'KeksNicoh' Heimann <www.salamipla.net>

 * @date 02nov08

 */

function pixelfuck($url, $chars='ewk34543§G§$§$Tg34g4g', $shrpns=1, $size=4,$weight=2)

{

    list($w, $h, $type) = getimagesize($url);

    $resource = imagecreatefromstring(file_get_contents($url));

    $img = imagecreatetruecolor($w*$size,$h*$size);



    $cc = strlen($chars);

    for($y=0;$y <$h;$y+=$shrpns) 

        for($x=0;$x <$w;$x+=$shrpns)

            imagestring($img,$weight,$x*$size,$y*$size, $chars{@++$p%$cc}, imagecolorat($resource, $x, $y));

    return $img;

}



$url = 'http://upload.wikimedia.org/wikipedia/commons/b/be/Manga_Icon.png';

$text = 'I-dont-like-manga-...-Why-do-they-have-such-big-eyes? Strange-...-WHAT-WANT-YOU-DO?';



Header('Content-Type: image/png');

imagepng(pixelfuck($url, $text, 1, 6));

?>



Have fun  :)

Abubaker dot shamlan at gmail dot com 19-Aug-2008 03:02


this is a function that is based on imagestring but it produces text in the center of an image i hope it helps :D





<?php


function ImageStringCenter($image_resource, $font_size, $line_number, $total_lines, $text, $color ) {





    $center_x = ceil( ( imagesx($image_resource) - ( ImageFontWidth($font_size) * strlen($text) ) ) / 2 );





    $center_y = ceil( ( ( imagesy($image_resource) - ( ImageFontHeight($font_size) * $total_lines ) ) / 2)  + ( ($line_number-1) * ImageFontHeight($font_size) ) );





ImageString($image_resource, $font_size, $center_x, $center_y, $text, $color );





}


?>

mustafa at hafunny dot info 14-Aug-2008 02:42


If you have any problem with CentralEurope's words, for example : ?????yáíéú?ň??, I am try this problem by iconv() function.



<?php

// create example image

$im = imagecreate(200, 20);

$bg = imagecolorallocate($im, 255, 255, 255);

$textcolor = imagecolorallocate($im, 0, 0, 255);

$text = "?????yáíéú?ň??...";



//simple convert string

$string = iconv("Windows-1250", "Latin2", $text);



// write converted string at the top left

imagestring($im, 4, 0, 0, $string, $textcolor);



// output the image

header("Content-type: image/png");

imagepng($im);

?>

sk89q 14-Mar-2008 02:10


Creates a box of text. Has horizontal and vertical alignment, box arguments, and custom leading. I submitted this to the manual in 2003 actually, but it disappeared after a year or so (not sure why). Here it is again.



<?php

define("ALIGN_LEFT", "left");

define("ALIGN_CENTER", "center");

define("ALIGN_RIGHT", "right");

define("VALIGN_TOP", "top");

define("VALIGN_MIDDLE", "middle");

define("VALIGN_BOTTOM", "bottom");



function imagestringbox(&$image, $font, $left, $top, $right, $bottom, $align, $valign, $leading, $text, $color)

{

   // Get size of box

   $height = $bottom - $top;

   $width = $right - $left;

  

   // Break the text into lines, and into an array

   $lines = wordwrap($text, floor($width / imagefontwidth($font)), "\n", true);

   $lines = explode("\n", $lines);

  

   // Other important numbers

   $line_height = imagefontheight($font) + $leading;

   $line_count = floor($height / $line_height);

   $line_count = ($line_count > count($lines)) ? (count($lines)) : ($line_count);

  

   // Loop through lines

   for ($i = 0; $i < $line_count; $i++)

   {

       // Vertical Align

       switch($valign)

       {

           case VALIGN_TOP: // Top

               $y = $top + ($i * $line_height);

               break;

           case VALIGN_MIDDLE: // Middle

               $y = $top + (($height - ($line_count * $line_height)) / 2) + ($i * $line_height);

               break;

           case VALIGN_BOTTOM: // Bottom

               $y = ($top + $height) - ($line_count * $line_height) + ($i * $line_height);

               break;

           default:

               return false;

       }

      

       // Horizontal Align

       $line_width = strlen($lines[$i]) * imagefontwidth($font);

       switch($align)

       {

           case ALIGN_LEFT: // Left

               $x = $left;

               break;

           case ALIGN_CENTER: // Center

               $x = $left + (($width - $line_width) / 2);

               break;

           case ALIGN_RIGHT: // Right

               $x = $left + ($width - $line_width);

               break;

           default:

               return false;

       }

      

       // Draw

       imagestring($image, $font, $x, $y, $lines[$i], $color);

   }

  

   return true;

}

?>

eviloverlord+php at gmail dot com 03-Jan-2008 03:28


Simple script to convert a string (such as an email addresses) to a transparent image.



Usage: 

<img src="stringtoimg.php?string=<?= urlencode(base64_encode($email)) ?>">



From a spambot's point of view, they see:

<img src="stringtoimg.php?string=ZpbXZG92ZXJsb3JkQGdtYWlsLmNvbQ%3D%3D">



Optional parameters:

    font_size: 1 to 5, with the default at 3

    R/G/B: the font color, in hex.



Usage:

<img src="stringtoimg.php?string=<?= urlencode(base64_encode($email)) ?>&font_size=4&R=FF&G=FF&B=00">



<?php

/*

Filename: stringtoimg.php



Parameters:

        string: the string to print

        font_size (optional): the size of the font from 1-5

        R/G/B (optional): the RGB colors of the font in hex       

*/



header ("Content-type: image/png");



//Get string info

$font_size = isset($_GET['font_size']) ? $_GET['font_size'] : 3;

$string = urldecode(base64_decode($_GET['string']));



//Get the size of the string

$width = imagefontwidth($font_size) * strlen($string);

$height = imagefontheight($font_size);



//Create the image

$img = @imagecreatetruecolor($width, $height)

      or die("Cannot Initialize new GD image stream");



//Make it transparent

imagesavealpha($img, true);

$trans_colour = imagecolorallocatealpha($img, 0, 0, 0, 127);

imagefill($img, 0, 0, $trans_colour);



//Get the text color

$text_color = isset($_GET['R'], $_GET['G'], $_GET['B']) ?

        imagecolorallocate($img, hexdec($_GET['R']), hexdec($_GET['G']), hexdec($_GET['B'])) :

        imagecolorallocate($img, 0, 0, 0);



//Draw the string

imagestring($img, $font_size, 0, 0,  $string, $text_color);



//Output the image

imagepng($img);

imagedestroy($img);

?>

Epidemiah 03-Jan-2008 05:06


Its just an easy function to write an string in the middle of a picture.



<?php



function imageCenterString(&$img, $font, $text, $color)

{

    if($font < 0 || $font > 5){ $font = 0; }

    $num = array(array(4.6, 6),

                 array(4.6, 6),

                 array(5.6, 12),

                 array(6.5, 12),

                 array(7.6, 16),

                 array(8.5, 16));

    $width = ceil(strlen($text) * $num[$font][0]);

    $x     = imagesx($img) - $width - 8;

    $y     = Imagesy($img) - ($num[$font][1] + 2);

    imagestring($img, $font, $x/2, $y/2, $text, $color);

}



?>

jlamer 18-Feb-2007 06:00


//  Example of use...



//  This is a simple function to output text to an image

//  which is centered (as much as I want to do by eye)

//  and wrapped

//    Just remember that all the sizes are guessed

// doesn't cut on the space (only on number of characters)

//  or change color of text, but this isn't for that...

function imageCenterString( $imgw, $imgh,

   $image_text = '', $text_size=5 )

{

   $im = imagecreate( $imgw, $imgh );

    

   // white background and blue text

   $bg = imagecolorallocate($im, 255, 255, 255);

   $textcolor = imagecolorallocate($im, 0, 0, 0);

    

   $t_h = $t_w = $t_x = $t_y = 0;

   $base_w =9; $base_h = 16;

   $m = 0.88;

   switch ( $text_size )

   {

      case 1: $t_w = $base_w*pow(($m*.98),4);

         $t_h = $base_h*pow(($m*.98),4);

         break;

      case 2: $t_w = $base_w*pow($m,3);

         $t_h = $base_h*pow($m,3);

         break;

      case 3: $t_w = $base_w*pow($m,2);

         $t_h = $base_h*pow($m,2);

         break;

      case 4: $t_w = $base_w*$m;

         $t_h = $base_h*$m;

         break;

      case 5: $t_w = $base_w;

         $t_h = $base_h;

         break;

      default:

         if ( $text_size >= 5 ) // set to 5

         {   $t_w = $base_w; $t_h = $base_h; }

         if ( $text_size < 5 ) // set to 1

         {

            $t_w = $base_w*pow(($m*.98),4);

            $t_h = $base_h*pow(($m*.98),4);

         }

         break;

   }

    

   $text_array = array();

    

   $max = floor($imgw/$t_w);

    

   for( $i=0; strlen($image_text) > 0; $i += $max)

   {

      array_push($text_array, substr($image_text,0,$max));

      if ( strlen($image_text) >= $max )

      {   $image_text = substr($image_text,$max); }

      else

      {   $image_text = ''; }

   }

    

   $t_y = ($imgh/2) - ($t_h*count($text_array)/2);



   foreach ( $text_array as $text )

   {

      $t_x = ($imgw/2)-($t_w*strlen($text)/2);

      imagestring($im, $text_size, $t_x, $t_y,

         $text, $textcolor);

      $t_y += $t_h;

   }



   // output the image

   header("Content-type: image/gpeg");

   imagejpeg($im);

}

gannon (at) portablesofdoom (dot) org 27-Dec-2006 06:53


I like this better than "tjpoe at cableaz dot com"'s function for wrapping text to fit width (auto-adjusts height as needed) since it doesn't only do 1 word per line.



function make_wrapped_txt($txt, $color=000000, $space=4, $font=4, $w=300) {

  if (strlen($color) != 6) $color = 000000;

  $int = hexdec($color);

  $h = imagefontheight($font);

  $fw = imagefontwidth($font);

  $txt = explode("\n", wordwrap($txt, ($w / $fw), "\n"));

  $lines = count($txt);

  $im = imagecreate($w, (($h * $lines) + ($lines * $space)));

  $bg = imagecolorallocate($im, 255, 255, 255);

  $color = imagecolorallocate($im, 0xFF & ($int >> 0x10), 0xFF & ($int >> 0x8), 0xFF & $int);

  $y = 0;

  foreach ($txt as $text) {

    $x = (($w - ($fw * strlen($text))) / 2);

    imagestring($im, $font, $x, $y, $text, $color);

    $y += ($h + $space);

  }

  header('Content-type: image/jpeg');

  die(imagejpeg($im));

}

iibm at free dot fr 14-Dec-2006 02:21


I've made a little modification of the (quite usefull) imagestringcutted function (when align=center, it doesn't work well for me if x1!=0) so juste replace the last line with :



<?php

   [...]

   else imagestring($img,$font,$x1+($x2-$x1)/ 2 - strlen($text) * $fontwidth / 2,$y,$text,$color);

}

?>

Piotr dot Sulecki at traxelektronik dot pl 09-Nov-2006 03:18


The built-in fonts used to be in latin-2 (iso8859-2) encoding. For some time, they are in latin-1 (iso8859-1) encoding. There is no way to change the encoding at all. If you need to use any other encoding, you have to use TrueType fonts.

god at in-heaven dot org 18-Oct-2006 02:47


Here's a simple function for creating an aligned string which is cutted to match the space between $x1 and $x2

<?php

function imagestringcutted($img,$font,$y,$x1,$x2,$text,$color,$align="center") {

    $fontwidth = imagefontwidth($font);

    $fullwidth = strlen($text) * $fontwidth;

    $maxwidth = $x2-$x1;

    $targetwidth = $fullwidth-(4*$fontwidth);

    if($fullwidth > $maxwidth) {

        for($i = 0; $i < strlen($text) AND ((strlen($text)-($i-4))*$fontwidth) > $targetwidth ;$i++) { }

        $text = substr($text,0,(strlen($text)-$i)-4)."...";

    }

    if($align == "left") imagestring($img,$font,$x1,$y,$text,$color);

    elseif($align == "right") imagestring($img,$font,$x2 - ((strlen($text) * $fontwidth)),$y,$text,$color);

    else imagestring($img,$font,($x2-$x1)/ 2 - strlen($text) * $fontwidth / 2,$y,$text,$color);

}

?>

Usage:

<?php

imagestringcutted($img,$font,$y,$x1,$x2,$text,$color,$align);

?>

Will create a string $text, which is cutted if it's too long to match between  $x1 and $2, on $img with font $font and color $color at height $y and with align to $align.

Hope it will help some people.

Sorry for my bad English.

rush at 507magazine dot com 28-Feb-2006 11:54


hello, I noticed that if you put a rand(3,5) it will put random sizes of font to each character put on the image. this is very useful when programming captchas for anti-spam form verification.

julien / at / theoconcept.com 01-Feb-2006 03:21


If you are looking for a way to generate a "CAPTCHA" image for a form verification (to verify it is not a robot), have a look at this : http://blog.theoconcept.com/static/distortion/



It gives an animated image with the parameter string, with distortion, here is an example :

http://blog.theoconcept.com/static/distortion/distortion.php



(*)  You'll need GD + Freetype support

(**) You'll need ImageMagick on the machine

m dot onderwater at esperantoxl dot nl 05-Dec-2005 10:55


There is a small error in the function for horizontal and vertical centering by "jurgen dot vanoosterwijck at pandora dot be"



the line 



 $cy = (imagesy($img)/2) - (imagefontwidth($font)/2);



should be



 $cy = (imagesy($img)/2) - (imagefontheight($font)/2);

aly at slo-igre dot net 11-Jun-2005 01:12


There is an error in "tjpoe at cableaz dot com" 's function ImageStringWrap. Instead of 



    else

           $string = $text;



there should be



     else

           $string = array($text);



for function to work for strings with only one word. Otherwise it works like a charm, thanks.

tjpoe at cableaz dot com 27-May-2005 07:48


i modified the centering functions and created this which centers each word on it's own line. You can adjust the spacing with the $valign var. currently no implimentation if text is too large for image. strings are tokenized by space, but can obviously be changed. 



function ImageStringWrap($image, $font, $text, $color)

{

  $fontwidth = ImageFontWidth($font);

  $fontheight = ImageFontHeight($font);

  $words= str_word_count($text);

  if ($words > 1){

    $string=array(strtok($text,' '));

    for ($i = 1 ; $i <= $words ; $i++){

      $string=array_merge($string,array($i=>strtok(' ')));

    }

  }

  else

    $string=$text;

  $vspace=4;

  $y=((imagesy($image)-($fontheight*$words)-($words*$vspace))/2);

  foreach($string as $st){

    $x=((imagesx($image)-($fontwidth * strlen($st)))/2);

    ImageString($image,$font,$x,$y,$st,$color);

    $y+=($fontheight+$vspace);

  }

}

hope this is helpful

bpgordon at gmail dot com 23-May-2005 04:04


This code produces a png image of the text within the query. It autofits to the length of the string. 

Usage: http://yoursite.com/text.php?abcdefg+hijk



Use + to produce a space in the image. The + can be excaped with a carat (^). Most other symbols work fine in the query string, like the ?.



<?php

header ("Content-type: image/png");

$string = $_ENV["QUERY_STRING"];

$md5 = md5($string); //just so we don't convert valid text into a +

$string = str_replace("^+", $md5, $string); //replaces ^+ with long, unnatural string

$string = str_replace("+", " ", $string); //replaces + with space

$string = str_replace($md5, "+", $string); //replaces the long, unnatural string with +

$width  = imagefontwidth($font) * strlen($string);

$height = imagefontheight($font);

$image = @imagecreate($width+2, $height+2);

$black = imagecolorallocate($image, 0, 0, 0); //background

$white = imagecolorallocate($image, 255, 255, 255);

imagestring($image, 2, 1, 1,  $string, $white);

imagepng($image);

imagedestroy($image);

?>

jurgen dot vanoosterwijck at pandora dot be 12-May-2005 10:52


Based on the previous example, here's how to center a string both horizontally and vertically...



<?php

function imagestringcentered ($img,$font,$text,$color) {

 while (strlen($text) * imagefontwidth($font) > imagesx($img)) {

  if ($font > 1) { $font--; }

  else { break; }

 } 

 $cy = (imagesy($img)/2) - (imagefontwidth($font)/2);

 imagestring($img,$font,imagesx($img) / 2 - strlen($text) * imagefontwidth($font) / 2,$cy,$text,$color);

}

?>

shadikka at gmail dot com 26-Mar-2005 11:49


My version of the centered string, it decreases the font number (since I've noticed smaller numbers are smaller fonts) until 1 if the string won't fit. Then it will give up.



<?php

function imagestringcentered ($img,$font,$cy,$text,$color) {

 while (strlen($text) * imagefontwidth($font) > imagesx($img)) {

  if ($font > 1) { $font--; }

  else { break; }

 }  

 imagestring($img,$font,imagesx($img) / 2 - strlen($text) * imagefontwidth($font) / 2,$cy,$text,$color);

}

?>

webmaster at acdrifter dot com 28-Feb-2005 08:08


If you are looking to center the text, use the following function; I'm not promising perfection...



function imagecenteredstring ( &$img, $font, $xMin, $xMax, $y, $str, $col ) {

    $textWidth = imagefontwidth( $font ) * strlen( $str );

    $xLoc = ( $xMax - $xMin - $textWidth ) / 2 + $xMin + $font;

    imagestring( $img, $font, $xLoc, $y, $str, $col );

}

cesargus at yahoo dot com 17-Nov-2004 10:27


//simple hello world



<?

header ("Content-type: image/png");



$img_handle = ImageCreate (200, 20) or die ("Cannot Create image");

$back_color = ImageColorAllocate ($img_handle, 0, 10, 10);

$txt_color = ImageColorAllocate ($img_handle, 235, 235, 51);

ImageString ($img_handle, 10, 25, 5,  "Hello world!", $txt_color);

ImagePng ($img_handle); 

?>

brooks dot boyd at gmail dot com 13-Oct-2004 12:35


Drawing a string as an image is a handy way to disguise an eMail address so spam sniffers can't get it as easily. The only catch to creating a dynamic image with your eMail in it is the eMail to be displayed must be passed via the query string to enable static HTML to use it. So, the eMail must be encrypted slightly in order to not defeat the purpose of not typing your eMail address outright. I wrote the following script to do so:



Save the following as email.php

<?php

    if ($_GET['addr'] != "") {

        $msg = $_GET['addr'];

        $msg = preg_replace("/\[dot]/",".",$msg);

        $msg = preg_replace("/\[at]/","@",$msg);

        $final = "";

        for ($i=0; $i<=strlen($msg); $i++) {

            $final .= substr($msg, strlen($msg)-$i, 1);

        }

        $msg = $final;



        $char_width = 8;

        $char_height = 17;

        $padding = 3;

        $width = $padding*2+strlen($msg)*$char_width;

        $height = +$padding*2+$char_height;

        $im = imagecreatetruecolor($width,$height);

        imagealphablending($im, FALSE);

        imagesavealpha($im, TRUE);

        $bg = imagecolorallocatealpha($im, 255, 255, 0, 100);

        $text = imagecolorallocatealpha($im, 0, 0, 0, 0);

        imagefilledrectangle ($im, 0, 0, $width, $height, $bg); # Make transparent

        imagestring($im, 4, $padding, $padding, $msg, $text);

    } else {

        $im = imagecreatetruecolor(1,1);

        imagealphablending($im, FALSE);

        imagesavealpha($im, TRUE);

        $bg = imagecolorallocatealpha($im, 255, 0, 0, 125);

        imagefilledrectangle ($im, 0, 0, 1, 1, $bg); # Make transparent

    }

    header('Content-type: image/jpg');

    imagepng($im);

    imagedestroy($im);



?>



If the script is called without an eMail address, it outputs a 2x2 transparent image.



To call the script to generate the eMail "user@home.com", the HTML tag would be:



<img src="email.php?addr=moc[dot]emoh[at]resu">



To 'encrypt' the eMail address to pass to the script, write the address backwards and replace "." with "[dot]" and "@" with "[at]". It's not the most ironclad protection, but it thwarts most casual eMail sniffers.

php dot net at mvoncken dot nl 14-Feb-2003 02:18


A simple example:

To make one line of text fit in the image.



<?php

header ("Content-type: image/png");

$string = "spam@mvoncken.nl";                                              

$font   = 4;

$width  = ImageFontWidth($font) * strlen($string);

$height = ImageFontHeight($font);



$im = @imagecreate ($width,$height);

$background_color = imagecolorallocate ($im, 255, 255, 255); //white background

$text_color = imagecolorallocate ($im, 0, 0,0);//black text

imagestring ($im, $font, 0, 0,  $string, $text_color);

imagepng ($im);

?>



I use something like this for spamprotection of my visitors (pass userid as an url-parameter for this php)

aholmes84 at hotmail dot com 08-Nov-2002 11:25


When setting the font, any integer less than 1 defaults to 1, and any integer greater than 5 defaults to 5.

deejay_world at yahoo dot com 10-Jun-2002 07:25


Width ImageString, the strings you draw are not automatically wrapped width the edge of the image. You may use this function to automatically wrap them:



function ImageStringWrap($image, $font, $x, $y, $text, $color, $maxwidth)

{

    $fontwidth = ImageFontWidth($font);

    $fontheight = ImageFontHeight($font);



    if ($maxwidth != NULL) {

        $maxcharsperline = floor($maxwidth / $fontwidth);

        $text = wordwrap($text, $maxcharsperline, "\n", 1);

      }



    $lines = explode("\n", $text);

    while (list($numl, $line) = each($lines)) {

        ImageString($image, $font, $x, $y, $line, $color);

        $y += $fontheight;

      }

}



So, in particular, if you want to wrap a text with the edge of the Image, you may do:

ImageStringWrap($img, $font, 0, $y, $text, $color, ImageSX($img) );

bob dot brown at opus dot co dot nz 02-Apr-2002 03:59


If you find that you are getting two characters on the end of your imageString that look like a Y and an upside down L then they're probably representations of CR/LF.  Try trim()ing the string before outputting it.  (I was sooo sure this was a bug <g>)

php教程 php手册 php手册

imagestring

说明

User Contributed Notes

php教程

php手册