Hiding the field in jasper report - jasper-reports

Question

I am working with jasper report-4.5.0.I want to hide a field in jasper based on the flag value.Below is tha code which i am using in columnHeader band.
<staticText>
<reportElement x="365" y="0" width="100" height="20"/>
<box>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font isBold="true"/>
</textElement>
<text><![CDATA[TotalCharge]]></text>
</staticText>
and below code i am using in detail band.
<textField>
<reportElement x="365" y="0" width="100" height="20">
<printWhenExpression><![CDATA[!$P{dataType}]]></printWhenExpression>
</reportElement>
<box>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Right" verticalAlignment="Middle">
<font size="8"/>
</textElement>
<textFieldExpression><![CDATA[$F{chargeTotal}]]></textFieldExpression>
</textField>
i am declaring the parameter in jrxml as
<parameter name="dataType" class="java.lang.Boolean"/>
the value to this parameter is coming from java class.If it is the false value i dont want to display this chargeTotal column.What i am doing wrong in my code.I am not getting.Any one can point me where i am doing wrong its urgent to me.

Answer 1

The code snippets you provided for the textfield look correct, but if you are wanting to hide the column header also you need to also add a printWhenExpression for it.
<staticText>
<reportElement x="365" y="0" width="100" height="20">
<printWhenExpression><![CDATA[$P{dataType}]]></printWhenExpression>
</reportElement>
<box>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font isBold="true"/>
</textElement>
<text><![CDATA[TotalCharge]]></text>
</staticText>
Edit: Actually, you have the conditional value backwards. If you want to show the column when dataType is true, your printWhenExpression needs to look like:
<printWhenExpression><![CDATA[$P{dataType}]]></printWhenExpression>