使用 PHP 管理演示文稿中的图表数据标签

本页内容简介

了解如何使用 Aspose.Slides for PHP via Java 在 PowerPoint 演示文稿中添加和格式化图表数据标签，以创建更具吸引力的幻灯片。

简介

数据标签显示有关图表系列和单个数据点的信息，帮助读者识别数值并理解图表。本文说明如何格式化数值、显示百分比、读取标签文本、调整类别轴标签间距以及定位饼图标签。

设置图表数据标签中的数据精度

使用 setNumberFormatOfValues 来格式化系列值。此示例创建了一个带有默认数据的折线图，显示其数据表，并为第一系列启用数值标签。格式 #,##0.00 显示千位分隔符和两位小数，而不更改底层值。

use aspose\slides\Presentation;
use aspose\slides\ChartType;
use aspose\slides\SaveFormat;

$presentation = new Presentation();
try {
    $slide = $presentation->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::Line, 50, 50, 450, 300);
    $chart->setDataTable(true);

    $series = $chart->getChartData()->getSeries()->get_Item(0);
    $series->setNumberFormatOfValues("#,##0.00");
    $series->getLabels()->getDefaultDataLabelFormat()->setShowValue(true);

    $presentation->save("PrecisionOfDatalabels_out.pptx", SaveFormat::Pptx);
} finally {
    $presentation->dispose();
}

以标签显示百分比

对于堆积柱形图，计算每个数值占其类别总计的百分比，并将文本分配给 getTextFrameForOverriding 返回的文本框。此示例使用默认的图表数据，并在 8 磅字号下显示带有两位小数的百分比。具有零总计的类别会被跳过，以避免除以零。如果图表数据更改，需要重新计算自定义标签文本。

use aspose\slides\Presentation;
use aspose\slides\ChartType;
use aspose\slides\Portion;
use aspose\slides\SaveFormat;

$presentation = new Presentation();
try {
    $slide = $presentation->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::StackedColumn, 20, 20, 400, 400);

    $categoryCount = java_values($chart->getChartData()->getCategories()->size());
    $categoryTotals = array_fill(0, $categoryCount, 0.0);
    for ($k = 0; $k < $categoryCount; $k++) {
        for ($i = 0; $i < java_values($chart->getChartData()->getSeries()->size()); $i++) {
            $series = $chart->getChartData()->getSeries()->get_Item($i);
            $pointValue = java_values($series->getDataPoints()->get_Item($k)->getValue()->getData());
            $categoryTotals[$k] += $pointValue;
        }
    }

    for ($x = 0; $x < java_values($chart->getChartData()->getSeries()->size()); $x++) {
        $series = $chart->getChartData()->getSeries()->get_Item($x);
        $series->getLabels()->getDefaultDataLabelFormat()->setShowLegendKey(false);

        for ($j = 0; $j < java_values($series->getDataPoints()->size()); $j++) {
            $label = $series->getDataPoints()->get_Item($j)->getLabel();
            if ($categoryTotals[$j] == 0) {
                continue;
            }

            $pointValue = java_values($series->getDataPoints()->get_Item($j)->getValue()->getData());
            $dataPointPercent = ($pointValue / $categoryTotals[$j]) * 100;

            $portion = new Portion();
            $portion->setText(sprintf("%.2F %%", $dataPointPercent));
            $portion->getPortionFormat()->setFontHeight(8);

            $label->getTextFrameForOverriding()->setText("");
            $paragraph = $label->getTextFrameForOverriding()->getParagraphs()->get_Item(0);
            $paragraph->getPortions()->add($portion);

            $label->getDataLabelFormat()->setShowValue(true);
            $label->getDataLabelFormat()->setShowSeriesName(false);
            $label->getDataLabelFormat()->setShowPercentage(false);
            $label->getDataLabelFormat()->setShowLegendKey(false);
            $label->getDataLabelFormat()->setShowCategoryName(false);
            $label->getDataLabelFormat()->setShowBubbleSize(false);
        }
    }

    $presentation->save("DisplayPercentageAsLabels_out.pptx", SaveFormat::Pptx);
} finally {
    $presentation->dispose();
}

使用图表数据标签设置百分号

当数值存储为分数时，使用 setNumberFormat 来显示百分比。将 false 传递给 setNumberFormatLinkedToSource，以使标签格式独立于源单元格。

此示例创建了一个 100% 堆积柱形图，包含红色和蓝色系列，跨四个类别。每对数值相加为 1。标签格式 0.0% 将 0.30 显示为 30.0%，而垂直轴使用两位小数。两个系列均使用白色、10 磅的标签文本。

use aspose\slides\Presentation;
use aspose\slides\ChartType;
use aspose\slides\FillType;
use aspose\slides\SaveFormat;

$presentation = new Presentation();
try {
    $slide = $presentation->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::PercentsStackedColumn, 20, 20, 500, 400);

    $chart->getAxes()->getVerticalAxis()->setNumberFormatLinkedToSource(false);
    $chart->getAxes()->getVerticalAxis()->setNumberFormat("0.00%");

    $chart->getChartData()->getSeries()->clear();
    $chart->getChartData()->getCategories()->clear();

    $workbook = $chart->getChartData()->getChartDataWorkbook();
    $worksheetIndex = 0;
    for ($i = 0; $i < 4; $i++) {
        $categoryCell = $workbook->getCell($worksheetIndex, $i + 1, 0, "Category " . ($i + 1));
        $chart->getChartData()->getCategories()->add($categoryCell);
    }

    $colors = java("java.awt.Color");
    $seriesNames = [ "Reds", "Blues" ];
    $seriesColors = [ $colors->RED, $colors->BLUE ];
    $values = [ [ 0.30, 0.50, 0.80, 0.65 ], [ 0.70, 0.50, 0.20, 0.35 ] ];

    for ($i = 0; $i < count($seriesNames); $i++) {
        $seriesCell = $workbook->getCell($worksheetIndex, 0, $i + 1, $seriesNames[$i]);
        $series = $chart->getChartData()->getSeries()->add($seriesCell, $chart->getType());
        for ($j = 0; $j < 4; $j++) {
            $valueCell = $workbook->getCell($worksheetIndex, $j + 1, $i + 1, $values[$i][$j]);
            $series->getDataPoints()->addDataPointForBarSeries($valueCell);
        }

        $series->getFormat()->getFill()->setFillType(FillType::Solid);
        $series->getFormat()->getFill()->getSolidFillColor()->setColor($seriesColors[$i]);

        $labelFormat = $series->getLabels()->getDefaultDataLabelFormat();
        $labelFormat->setShowValue(true);
        $labelFormat->setNumberFormatLinkedToSource(false);
        $labelFormat->setNumberFormat("0.0%");
        $labelFormat->getTextFormat()->getPortionFormat()->setFontHeight(10);
        $labelFormat->getTextFormat()->getPortionFormat()->getFillFormat()->setFillType(FillType::Solid);
        $labelFormat->getTextFormat()->getPortionFormat()->getFillFormat()->getSolidFillColor()->setColor($colors->WHITE);
    }

    $presentation->save("SetDataLabelsPercentageSign_out.pptx", SaveFormat::Pptx);
} finally {
    $presentation->dispose();
}

读取数据标签的实际文本

使用 getActualLabelText 来获取数据标签设置产生的文本。这在为报告提取标签、搜索演示文稿内容或验证生成的图表时非常有用。在下面的示例中，默认的 data label format 将每个类别名称、系列名称和数值组合在一起。一个点将其数值格式化为百分比，另一个使用来自 getTextFrameForOverriding 的自定义文本。

use aspose\slides\Presentation;
use aspose\slides\ChartType;

$presentation = new Presentation();
try {
    $slide = $presentation->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::ClusteredColumn, 20, 20, 500, 300);

    $chart->getChartData()->getSeries()->clear();
    $chart->getChartData()->getCategories()->clear();

    $workbook = $chart->getChartData()->getChartDataWorkbook();
    $firstCategoryCell = $workbook->getCell(0, 1, 0, "Q1");
    $chart->getChartData()->getCategories()->add($firstCategoryCell);
    $secondCategoryCell = $workbook->getCell(0, 2, 0, "Q2");
    $chart->getChartData()->getCategories()->add($secondCategoryCell);

    $northSeriesCell = $workbook->getCell(0, 0, 1, "North");
    $north = $chart->getChartData()->getSeries()->add($northSeriesCell, $chart->getType());
    $northFirstValueCell = $workbook->getCell(0, 1, 1, 0.25);
    $north->getDataPoints()->addDataPointForBarSeries($northFirstValueCell);
    $northSecondValueCell = $workbook->getCell(0, 2, 1, 0.75);
    $north->getDataPoints()->addDataPointForBarSeries($northSecondValueCell);

    $southSeriesCell = $workbook->getCell(0, 0, 2, "South");
    $south = $chart->getChartData()->getSeries()->add($southSeriesCell, $chart->getType());
    $southFirstValueCell = $workbook->getCell(0, 1, 2, 0.40);
    $south->getDataPoints()->addDataPointForBarSeries($southFirstValueCell);
    $southSecondValueCell = $workbook->getCell(0, 2, 2, 0.60);
    $south->getDataPoints()->addDataPointForBarSeries($southSecondValueCell);

    for ($i = 0; $i < java_values($chart->getChartData()->getSeries()->size()); $i++) {
        $series = $chart->getChartData()->getSeries()->get_Item($i);
        $format = $series->getLabels()->getDefaultDataLabelFormat();
        $format->setShowCategoryName(true);
        $format->setShowSeriesName(true);
        $format->setShowValue(true);
    }

    $north->getLabels()->get_Item(1)->getDataLabelFormat()->setNumberFormatLinkedToSource(false);
    $north->getLabels()->get_Item(1)->getDataLabelFormat()->setNumberFormat("0%");
    $south->getLabels()->get_Item(0)->getTextFrameForOverriding()->setText("Reviewed");

    for ($i = 0; $i < java_values($chart->getChartData()->getSeries()->size()); $i++) {
        $series = $chart->getChartData()->getSeries()->get_Item($i);
        for ($j = 0; $j < java_values($series->getDataPoints()->size()); $j++) {
            $point = $series->getDataPoints()->get_Item($j);
            $label = $point->getLabel();
            if (!java_values($label->isVisible())) {
                continue;
            }

            echo "Value: " . java_values($point->getValue()->getData()) . "; label: " . java_values($label->getActualLabelText()) . PHP_EOL;
        }
    }
} finally {
    $presentation->dispose();
}

数据点中存储的数值仍为 0.75，即使其标签显示了包括类别和系列名称的 75%。自定义文本会替换生成的标签文本。无论哪种情况，getActualLabelText 都返回结果标签字符串。当您只想提取可见标签时，如上所示，请单独检查 isVisible。

设置标签与坐标轴的距离

使用 setLabelOffset 来控制类别轴标签与坐标轴之间的距离。该值是轴标签最大字体大小的百分比。此示例创建了一个簇状柱形图，并将水平轴标签偏移设置为 500。此设置影响类别轴标签，而不是附加在单个数据点上的标签。

use aspose\slides\Presentation;
use aspose\slides\ChartType;
use aspose\slides\SaveFormat;

$presentation = new Presentation();
try {
    $slide = $presentation->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::ClusteredColumn, 20, 20, 500, 300);
    $chart->getAxes()->getHorizontalAxis()->setLabelOffset(500);

    $presentation->save("SetCategoryAxisLabelDistance_out.pptx", SaveFormat::Pptx);
} finally {
    $presentation->dispose();
}

调整标签位置

在饼图上，调整数据标签的位置以改善间距并为引导线留出空间。

此示例显示第一个数据点的值，将其标签放置在切片外部，并使用 setX 和 setY 调整水平和垂直偏移。这些偏移量分别相对于图表的宽度和高度。

use aspose\slides\Presentation;
use aspose\slides\ChartType;
use aspose\slides\LegendDataLabelPosition;
use aspose\slides\SaveFormat;

$presentation = new Presentation();
try {
    $slide = $presentation->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::Pie, 50, 50, 200, 200);
    $series = $chart->getChartData()->getSeries();

    $label = $series->get_Item(0)->getLabels()->get_Item(0);
    $label->getDataLabelFormat()->setShowValue(true);
    $label->getDataLabelFormat()->setPosition(LegendDataLabelPosition::OutsideEnd);
    $label->setX(0.71);
    $label->setY(0.04);

    $presentation->save("presentation.pptx", SaveFormat::Pptx);
} finally {
    $presentation->dispose();
}

常见问题

如何防止在密集图表上数据标签重叠？

结合自动标签布局、引导线和减小字体大小；如果必要，可隐藏某些字段（例如类别），或仅对极值或关键点显示标签。

如何仅对零、负数或空值禁用标签？

在启用标签之前过滤数据点，并根据定义的规则关闭对 0、负值或缺失值的显示。

在导出为 PDF/图像时，如何确保标签样式一致？

显式设置字体族和大小，并确认渲染环境中提供了该字体，以避免回退。