当printWhenExpression为false时，如何在框架上保持相同的行为，好像它不存在？

Question

所以我有一个包含两个框架的明细带，第一个框架包含几个元素，其中包括一个子报表，第二个框架仅包含一个文本字段。

我遇到的问题是，如果我从乐队中删除第二帧，所有内容将保留在同一页面中。如果我添加第二帧并使用printonly表达式不显示它，则它将整个内容更改为下一页。如果第二帧为空，是否有办法强迫这种行为，使行为看起来根本不存在？]

<band height="160" splitType="Prevent">
        <property name="local_mesure_unitheight" value="pixel"/>
        <property name="com.jaspersoft.studio.unit.height" value="px"/>
        <property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.FreeLayout"/>
        <frame>
            <reportElement isPrintRepeatedValues="false" x="0" y="1" width="556" height="116" isRemoveLineWhenBlank="true" uuid="3aca49ee-4b55-452c-a8c6-5cc252c4175c">
                <property name="local_mesure_unitheight" value="pixel"/>
                <property name="com.jaspersoft.studio.unit.height" value="px"/>
            </reportElement>
            <subreport>
                <reportElement positionType="Float" x="2" y="65" width="160" height="51" uuid="438d3f08-7b8a-4b61-b17f-19993aa5abe4">
                    <property name="local_mesure_unitx" value="pixel"/>
                    <property name="com.jaspersoft.studio.unit.x" value="cm"/>
                </reportElement>
                <subreportParameter name="DOC_ID">
                    <subreportParameterExpression><![CDATA[$P{DOC_ID}]]></subreportParameterExpression>
                </subreportParameter>
                <subreportParameter name="IS_RUNNING_LOCAL">
                    <subreportParameterExpression><![CDATA[$P{IS_RUNNING_LOCAL}]]></subreportParameterExpression>
                </subreportParameter>
                <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.JREmptyDataSource()]]></dataSourceExpression>
                <subreportExpression><![CDATA[$P{IS_RUNNING_LOCAL} ? "/Reports/Common/xxxxxxxxxxxxxxSub.jasper" : "repo:/Reports/Common/xxxxxxxxxxxxxxSub"]]></subreportExpression>
            </subreport>
            <textField isStretchWithOverflow="true">
                <reportElement style="Default" positionType="Float" mode="Transparent" x="1" y="1" width="552" height="30" isRemoveLineWhenBlank="true" forecolor="#000000" backcolor="#FFFFFF" uuid="837c85bf-7a2a-4eb5-919d-bd16d4bc64f2">
                    <property name="local_mesure_unitwidth" value="pixel"/>
                    <property name="local_mesure_unity" value="pixel"/>
                    <property name="com.jaspersoft.studio.unit.y" value="px"/>
                    <property name="com.jaspersoft.studio.unit.width" value="px"/>
                    <property name="com.jaspersoft.studio.unit.x" value="cm"/>
                    <property name="local_mesure_unitheight" value="pixel"/>
                </reportElement>
                <box padding="0" topPadding="0" leftPadding="0" bottomPadding="0" rightPadding="0"/>
                <textElement textAlignment="Justified" verticalAlignment="Top" rotation="None" markup="html">
                    <font fontName="Arial" size="10" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
                    <paragraph lineSpacing="Single" lineSpacingSize="1.0" firstLineIndent="0" leftIndent="0" rightIndent="0" spacingBefore="0" spacingAfter="0" tabStopWidth="40"/>
                </textElement>
                <textFieldExpression><![CDATA["xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"]]></textFieldExpression>
            </textField>
            <textField>
                <reportElement style="Default" positionType="Float" mode="Transparent" x="2" y="43" width="511" height="17" forecolor="#000000" backcolor="#FFFFFF" uuid="3e1c3952-6578-4d5f-85a3-d706fc5a5fbb">
                    <property name="local_mesure_unitwidth" value="pixel"/>
                    <property name="com.jaspersoft.studio.unit.width" value="px"/>
                    <property name="local_mesure_unitx" value="cm"/>
                    <property name="com.jaspersoft.studio.unit.x" value="cm"/>
                    <property name="local_mesure_unitheight" value="pixel"/>
                </reportElement>
                <box padding="0" topPadding="0" leftPadding="0" bottomPadding="0" rightPadding="0"/>
                <textElement textAlignment="Justified" verticalAlignment="Top" rotation="None" markup="html">
                    <font fontName="Arial" size="9" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
                    <paragraph lineSpacing="Single" lineSpacingSize="1.0" firstLineIndent="0" leftIndent="0" rightIndent="0" spacingBefore="0" spacingAfter="0" tabStopWidth="40"/>
                </textElement>
                <textFieldExpression><![CDATA["testetestestestestestes"]]></textFieldExpression>
            </textField>
        </frame>
        <frame>
            <reportElement positionType="Float" x="1" y="120" width="555" height="40" isRemoveLineWhenBlank="true" uuid="c3bf96ce-dd19-41f1-bf13-fe1dd46d8d4e">
                <property name="local_mesure_unitheight" value="pixel"/>
                <property name="com.jaspersoft.studio.unit.height" value="px"/>
                <property name="local_mesure_unitwidth" value="pixel"/>
                <property name="com.jaspersoft.studio.unit.width" value="px"/>
                <printWhenExpression><![CDATA[$P{COD_DOC}.equals("xx_xxx_xxx")]]></printWhenExpression>
            </reportElement>
            <textField isBlankWhenNull="true">
                <reportElement positionType="Float" isPrintRepeatedValues="false" mode="Transparent" x="1" y="0" width="551" height="39" isRemoveLineWhenBlank="true" uuid="c1ab35b8-31a6-41e9-a260-71bbcab8692e">
                    <property name="local_mesure_unitwidth" value="pixel"/>
                    <property name="com.jaspersoft.studio.unit.width" value="px"/>
                    <printWhenExpression><![CDATA[$P{COD_DOC}.equals("xx_xxx_xxx")]]></printWhenExpression>
                </reportElement>
                <textElement textAlignment="Justified">
                    <font size="10"/>
                </textElement>
                <textFieldExpression><![CDATA["PS: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"]]></textFieldExpression>
            </textField>
        </frame>
    </band>

Answer 1

如果第二帧为空，是否有办法强制其维持行为，好像根本不存在？

解决方案是使用多个细节带并将printWhenExpression设置为细节带

<?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="TestParams" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="f85bc6aa-5060-4485-bd99-bd5de1734ef1">
<queryString>
        <![CDATA[]]>
    </queryString>
    <detail>
        <band height="116">
           <break>
            <reportElement x="0" y="5" width="100" height="1" uuid="fb9c89cd-1b6a-44f5-82a9-99e9996229e3">
                <printWhenExpression><![CDATA[$P{COD_DOC}.equals("xx_xxx_xxx")]]></printWhenExpression>
            </reportElement>
           </break>
            <frame>
                <reportElement x="0" y="10" width="200" height="116" uuid="e6890adf-6ff1-49f6-9c47-ba6f171a2c60"/>
            </frame>
        </band>
        <band height="40">
            <printWhenExpression><![CDATA[$P{COD_DOC}.equals("xx_xxx_xxx")]]></printWhenExpression>
            <frame>
                <reportElement x="0" y="0" width="200" height="40" uuid="d9f8ba4a-e435-49ff-9ff7-d23e55aecc52"/>
            </frame>
        </band>
    </detail>
</jasperReport>

这样，如果第二个组件未显示/未打印，则整个带（高度）将被删除，并且其行为就像只有第一个带存在。