修改excel 模板下载功能， 修改下拉框设置 改为隐藏sheet中拉取下拉框内容，避免单元格超255数值上限错误

yudao-framework/yudao-spring-boot-starter-excel/src/main/java/cn/iocoder/yudao/framework/excel/core/util/SpinnerWriteHandler.java

@@ -3,10 +3,7 @@ package cn.iocoder.yudao.framework.excel.core.util;
 import com.alibaba.excel.write.handler.SheetWriteHandler;
 import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
 import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
-import org.apache.poi.ss.usermodel.DataValidation;
+import org.apache.poi.ss.usermodel.*;
-import org.apache.poi.ss.usermodel.DataValidationConstraint;
-import org.apache.poi.ss.usermodel.DataValidationHelper;
-import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.util.CellRangeAddressList;
 import org.apache.poi.xssf.usermodel.XSSFDataValidation;
 
@@ -49,11 +46,40 @@ public class SpinnerWriteHandler implements SheetWriteHandler {
         Sheet sheet = writeSheetHolder.getSheet();
         /// 开始设置下拉框
         DataValidationHelper helper = sheet.getDataValidationHelper();// 设置下拉框
+
+        //定义sheet的名称
+        String hiddenName = "hidden";
+
+        //1.创建一个隐藏的sheet 名称为 hidden
+        Workbook workbook = writeWorkbookHolder.getWorkbook();
+        Sheet hidden = workbook.createSheet(hiddenName);
+        Name category1Name = workbook.createName();
+        category1Name.setNameName(hiddenName);
+
         for (Map.Entry<Integer, String[]> entry : mapDropDown.entrySet()) {
+
             /*** 起始行、终止行、起始列、终止列 **/
             CellRangeAddressList addressList = new CellRangeAddressList(1, 1000, entry.getKey(), entry.getKey());
+
+            // 获取excel列名
+            String excelLine = getExcelLine(entry.getKey());
+
+            // 循环赋值
+            String[] values = entry.getValue();
+            for (int i = 0, length = values.length; i < length; i++) {
+                // 3:表示你开始的行数  3表示 你开始的列数
+                Row row = hidden.getRow(i);
+                if (row == null) {
+                    row = hidden.createRow(i);
+                }
+                row.createCell(entry.getKey()).setCellValue(values[i]);
+            }
+            // hidden!$H:$1:$H$50  sheet为hidden的 H1列开始H50行数据获取下拉数组
+            String refers =  hiddenName + "!$"+excelLine+
+                    "$1:$"+excelLine +"$"+ (values.length);
+
             /*** 设置下拉框数据 **/
-            DataValidationConstraint constraint = helper.createExplicitListConstraint(entry.getValue());
+            DataValidationConstraint constraint = helper.createFormulaListConstraint(refers);
             DataValidation dataValidation = helper.createValidation(constraint, addressList);
             /*** 处理Excel兼容性问题 **/
             if (dataValidation instanceof XSSFDataValidation) {
@@ -65,5 +91,27 @@ public class SpinnerWriteHandler implements SheetWriteHandler {
             }
             sheet.addValidationData(dataValidation);
         }
+
+        //设置列为隐藏
+        int hiddenIndex = workbook.getSheetIndex("hidden");
+        if (!workbook.isSheetHidden(hiddenIndex)) {
+            workbook.setSheetHidden(hiddenIndex, true);
+        }
+    }
+
+    /**
+     * 返回excel列标A-Z-AA-ZZ
+     * @param num 列数
+     * @return java.lang.String
+     */
+    public static String getExcelLine(int num) {
+        String line = "";
+        int first = num/26;
+        int second = num % 26;
+        if (first>0) {
+            line = (char)('A'+first-1)+"";
+        }
+        line += (char)('A'+second)+"";
+        return line;
     }
 }