PHP Libchart 圖表庫繪製統計圖完整教學

Libchart 簡介

Libchart 是純 PHP 繪圖庫，支援長條圖、折線圖、圓餅圖、水平長條圖，需 GD 擴展支援。

封裝類別範例

<?php
require "./libchart/classes/libchart.php";

class drawPic {
    var $chart;
    var $style;

    function drawPic($style = "1", $width = "500", $height = "250") {
        $this->style = $style;
        if ($style == 1) {
            $this->chart = new VerticalBarChart($width, $height);
        } elseif ($style == 2) {
            $this->chart = new LineChart($width, $height);
        } elseif ($style == 3) {
            $this->chart = new PieChart($width, $height);
        } else {
            $this->chart = new HorizontalBarChart($width, $height);
        }
    }

    function draw($obj) {
        if ($this->style == 1 || $this->style == "1") {
            $dataSet = new XYDataSet();
            $this->chart->setTitle($obj->title);
            foreach ($obj->dataArray as $key => $val) {
                $dataSet->addPoint(new Point($key, $val));
            }
            $this->chart->setDataSet($dataSet);
            $this->chart->render();
        } elseif ($this->style == 2 || $this->style == "2") {
            $this->chart->setTitle($obj->title);
            $i = 0;
            $dataSet = new XYSeriesDataSet();
            foreach ($obj->dataArray as $key => $val) {
                $serie[$i] = new XYDataSet();
                foreach ($val as $k => $v) {
                    $serie[$i]->addPoint(new Point($k, $v));
                }
                $dataSet->addSerie($key, $serie[$i]);
                $i++;
            }
            $this->chart->setDataSet($dataSet);
            $this->chart->render();
        } elseif ($this->style == 3) {
            $dataSet = new XYDataSet();
            $this->chart->setTitle($obj->title);
            foreach ($obj->dataArray as $key => $val) {
                $dataSet->addPoint(new Point($key . "($val)", $val));
            }
            $this->chart->setDataSet($dataSet);
            $this->chart->render();
        } else {
            $dataSet = new XYDataSet();
            $this->chart->setTitle($obj->title);
            foreach ($obj->dataArray as $key => $val) {
                $dataSet->addPoint(new Point($key, $val));
            }
            $this->chart->setDataSet($dataSet);
            $this->chart->render();
        }
    }
}

// 使用範例
$n = new drawPic("4");
$k = new stdClass();
$k->dataArray = array("2000" => "30", "2001" => "40", "2002" => "50", "2003" => "60", "2004" => "70", "2005" => "80", "20020" => "90");
$k->title = "The Sheet title";
$n->draw($k);
?>

中文亂碼解決方案

1. 資料標籤轉碼

<?php
header("content-type:image/png");
require_once('libchart/classes/libchart.php');

$chart = new VerticalBarChart(500, 250);
$dataSet = new XYDataSet();

$str = '二月';
$str = mb_convert_encoding($str, "html-entities", "utf-8");

$dataSet->addPoint(new Point("Jan 2005", 273));
$dataSet->addPoint(new Point($str, 120));
$dataSet->addPoint(new Point("March 2005", 442));
$dataSet->addPoint(new Point("April 2005", 600));

$chart->setDataSet($dataSet);
$chart->setTitle("統計圖");
$chart->render();
?>

2. 標題亂碼修正

修改 libchart/classes/view/chart/Chart.php 的 setTitle 方法：

public function setTitle($title) {
    $title = mb_convert_encoding($title, "html-entities", "utf-8");
    $this->plot->setTitle($title);
}

3. 字體替換

修改 libchart/classes/view/text.php 第 47-48 行：

$this->fontCondensed = dirname(__FILE__) . "/../fonts/你的中文字體.ttf";
$this->fontCondensedBold = dirname(__FILE__) . "/../fonts/你的中文字體.ttf";

需將中文字體（如微軟正黑體、文泉驛等）放入 fonts 目錄，且 PHP 檔案儲存為 UTF-8 編碼。