grails - 如果语句简单(？)

Question

因此，尝试做某事(我认为应该很简单)
在代码中进一步设置一个值，然后执行if语句检查我设置的值。
设置变量的代码段。复制在下面

if ( params.headers == null) {
    def headline="1"
    render ("Starting to read on line 1<BR>")
} else {
    def headline="0"
    render ("Skipping line 1<BR>")
}

然后在 Controller 中往下走一点，我执行以下操作

if ( headline == "0") {
    render "Skipped line for ${fields[0]}"
    headline = "1"
} else {

每当我运行此命令时，我都会收到以下错误消息”

No such property: headline for class: regmap.CountryuploadController. Stacktrace follows:
Message: No such property: headline for class: regmap.CountryuploadController
    Line | Method
->>   25 | doCall    in regmap.CountryuploadController$_loadcsv_closure1$$EOrLxdfM
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|     34 | eachLine  in org.grails.plugins.csv.CSVReaderUtils
|     47 | eachLine  in     ''
|    140 | doCall    in CsvGrailsPlugin$_closure4_closure12
|     22 | loadcsv . in regmap.CountryuploadController$$EOrLxdfM
|    198 | doFilter  in grails.plugin.cache.web.filter.PageFragmentCachingFilter
|     63 | doFilter  in grails.plugin.cache.web.filter.AbstractFilter
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread

有任何想法吗？
很明显我错过了一些东西，甚至我试图互相追逐。

Answer 1

由于您在headline和if块内声明了else变量，因此其范围仅限于这些块，这就是为什么稍后尝试引用它时会出错的原因。您想要这样的东西:

def headline
if ( params.headers == null) {
    headline="1"
    render ("Starting to read on line 1<BR>")
} else {
    headline="0"
    render ("Skipping line 1<BR>")
}