当Table组件为空时如何显示一些文本

Question

我有一个主报告，它调用了一个子报告。该子报表有一个使用数据集的表。

我想在表中没有记录时显示一条消息。这个怎么做？

Answer 1

表组件后面带有所需文本（例如，无数据文本）的“假”静态文本，与删除的表的whenNoDataType属性配合应该可以解决此任务。

样本

<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="Blank_A4_27" pageWidth="595" pageHeight="842" whenNoDataType="AllSectionsNoDetail" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="95f68ce4-441a-425c-88fb-b48fe96fac6b">
    <property name="com.jaspersoft.studio.data.defaultdataadapter" value="One Empty Record"/>
    <style name="Table_TH" mode="Opaque" backcolor="#F0F8FF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <style name="Table_CH" mode="Opaque" backcolor="#BFE1FF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <style name="Table_TD" mode="Opaque" backcolor="#FFFFFF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <subDataset name="Empty Dataset1" uuid="21916aaf-ceb1-456b-a45e-6c31863ac208"/>
    <queryString>
        <![CDATA[]]>
    </queryString>
    <title>
        <band height="252" splitType="Stretch">
            <staticText>
                <reportElement x="0" y="40" width="555" height="35" uuid="ff8a82ab-c00f-422a-a907-06d4021b87bd"/>
                <textElement textAlignment="Center" verticalAlignment="Middle">
                    <font fontName="SansSerif" size="18" isBold="true"/>
                </textElement>
                <text><![CDATA[No data]]></text>
            </staticText>
            <componentElement>
                <reportElement x="0" y="20" width="555" height="200" uuid="1a91c926-a553-4eab-bc04-938c1a962f9a">
                    <property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.VerticalRowLayout"/>
                    <property name="com.jaspersoft.studio.table.style.table_header" value="Table_TH"/>
                    <property name="com.jaspersoft.studio.table.style.column_header" value="Table_CH"/>
                    <property name="com.jaspersoft.studio.table.style.detail" value="Table_TD"/>
                </reportElement>
                <jr:table xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components http://jasperreports.sourceforge.net/xsd/components.xsd" whenNoDataType="AllSectionsNoDetail">
                    <datasetRun subDataset="Empty Dataset1" uuid="1834081e-7aa0-4719-a0ac-e077f259cc18">
                        <connectionExpression><![CDATA[$P{REPORT_CONNECTION}]]></connectionExpression>
                    </datasetRun>
                    <jr:column width="555" uuid="eb741b0d-640c-48d1-b653-03703ce9e27e">
                        <jr:tableHeader style="Table_TH" height="30"/>
                        <jr:tableFooter style="Table_TH" height="30"/>
                        <jr:columnHeader style="Table_CH" height="30"/>
                        <jr:columnFooter style="Table_CH" height="30"/>
                        <jr:detailCell style="Table_TD" height="30"/>
                    </jr:column>
                </jr:table>
            </componentElement>
        </band>
    </title>
</jasperReport>

在Jaspersoft Studio ( JSS ) 中，设计如下所示：

输出结果

如果我们对表的数据集应用“所有部分无详细信息”值（ whenNoDataType属性）：

• 在JSS中，可以使用“当没有数据类型时”组合框设置此设置：

• 或者在jrxml中

<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="Blank_A4_27" pageWidth="595" pageHeight="842" whenNoDataType="AllSectionsNoDetail" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="95f68ce4-441a-425c-88fb-b48fe96fac6b">
    <property name="com.jaspersoft.studio.data.defaultdataadapter" value="One Empty Record"/>
    <style name="Table_TH" mode="Opaque" backcolor="#F0F8FF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <style name="Table_CH" mode="Opaque" backcolor="#BFE1FF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <style name="Table_TD" mode="Opaque" backcolor="#FFFFFF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <subDataset name="Empty Dataset1" uuid="21916aaf-ceb1-456b-a45e-6c31863ac208"/>
    <queryString>
        <![CDATA[]]>
    </queryString>
    <title>
        <band height="252" splitType="Stretch">
            <staticText>
                <reportElement x="0" y="40" width="555" height="35" uuid="ff8a82ab-c00f-422a-a907-06d4021b87bd"/>
                <textElement textAlignment="Center" verticalAlignment="Middle">
                    <font fontName="SansSerif" size="18" isBold="true"/>
                </textElement>
                <text><![CDATA[No data]]></text>
            </staticText>
            <componentElement>
                <reportElement x="0" y="20" width="555" height="200" uuid="1a91c926-a553-4eab-bc04-938c1a962f9a">
                    <property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.VerticalRowLayout"/>
                    <property name="com.jaspersoft.studio.table.style.table_header" value="Table_TH"/>
                    <property name="com.jaspersoft.studio.table.style.column_header" value="Table_CH"/>
                    <property name="com.jaspersoft.studio.table.style.detail" value="Table_TD"/>
                </reportElement>
                <jr:table xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components http://jasperreports.sourceforge.net/xsd/components.xsd" whenNoDataType="AllSectionsNoDetail">
                    <datasetRun subDataset="Empty Dataset1" uuid="1834081e-7aa0-4719-a0ac-e077f259cc18">
                        <connectionExpression><![CDATA[$P{REPORT_CONNECTION}]]></connectionExpression>
                    </datasetRun>
                    <jr:column width="555" uuid="eb741b0d-640c-48d1-b653-03703ce9e27e">
                        <jr:tableHeader style="Table_TH" height="30"/>
                        <jr:tableFooter style="Table_TH" height="30"/>
                        <jr:columnHeader style="Table_CH" height="30"/>
                        <jr:columnFooter style="Table_CH" height="30"/>
                        <jr:detailCell style="Table_TD" height="30"/>
                    </jr:column>
                </jr:table>
            </componentElement>
        </band>
    </title>
</jasperReport>

显示空表的结果将是：

如果删除此属性（当NoDataType为NULL时），结果将是：

在这种情况下，jrxml中的表标签将是：

<jr:table xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components http://jasperreports.sourceforge.net/xsd/components.xsd">