文章目录：
- 单一下拉框
- 级联下拉框
具体实现：
- 单一下拉框
java
public class BoolWriteHandler implements SheetWriteHandler {
private List<String> dropDown;
private List<Integer> indexList;
public BoolWriteHandler(List<Integer> indexList,List<String> dropDown) {
this.indexList = indexList;
this.dropDown =dropDown;
}
@Override
public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
// 定义一个map key是需要添加下拉框的列的index value是下拉框数据
Map<Integer, String[]> mapDropDown = new HashMap<>(2);
//下拉选项
String[] downArray = dropDown.toArray(new String[dropDown.size()]);
//下拉选在Excel中对应的列
for (Integer index : indexList) {
mapDropDown.put(index, downArray);
}
// 获取Sheet表
Sheet st = writeSheetHolder.getSheet();
//设置下拉框
DataValidationHelper helper = st.getDataValidationHelper();
for (Map.Entry<Integer, String[]> entry : mapDropDown.entrySet()) {
// 起始行、终止行、起始列、终止列 起始行为1即表示表头不设置
CellRangeAddressList addressList = new CellRangeAddressList(1, 999, entry.getKey(), entry.getKey());
// 设置下拉框数据 (设置长度为0的数组会报错，所以这里需要判断)
if (entry.getValue().length > 0) {
//创建显式列表约束
DataValidationConstraint constraint = helper.createExplicitListConstraint(entry.getValue());
// 指定行列约束以及错误信息
setValidation(st,helper,constraint,addressList,"提示","请选择下拉框中的值");
}
}
}
}
java
/**
* 字段校验
*/
private void setValidation(Sheet sheet, DataValidationHelper helper, DataValidationConstraint constraint, CellRangeAddressList addressList, String msgHead, String msgContext) {
DataValidation dataValidation = helper.createValidation(constraint, addressList);
dataValidation.setErrorStyle(DataValidation.ErrorStyle.STOP);
dataValidation.setShowErrorBox(true);
dataValidation.setSuppressDropDownArrow(true);
dataValidation.createErrorBox(msgHead, msgContext);
sheet.addValidationData(dataValidation);-
级联下拉框
-
2级级联
java
public class CascadeWriteHandler implements SheetWriteHandler {
private static char[] alphabet = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
private List<String> dropDown;
private List<String> cityList;
Map<String, List<String>> cityCountyMap;
private Integer provinceIndex;
private Integer cityIndex;
private Integer countyIndex;
public CascadeWriteHandler(List<String> dropDown, List<String> cityList, Map<String, List<String>> cityCountyMap,Integer provinceIndex,Integer cityIndex,Integer countyIndex) {
this.dropDown =dropDown;
this.cityList = cityList;
this.cityCountyMap = cityCountyMap;
this.provinceIndex = provinceIndex;
this.cityIndex = cityIndex;
this.countyIndex = countyIndex;
}
@Override
public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
// 省份固定
// 定义一个map key是需要添加下拉框的列的index value是下拉框数据
Map<Integer, String[]> mapDropDown = new HashMap<>(2);
//下拉选项
String[] downArray = dropDown.toArray(new String[dropDown.size()]);
//下拉选在Excel中对应的列
mapDropDown.put(provinceIndex, downArray);
// 获取Sheet表
Sheet st = writeSheetHolder.getSheet();
//设置下拉框
DataValidationHelper helper = st.getDataValidationHelper();
for (Map.Entry<Integer, String[]> entry : mapDropDown.entrySet()) {
// 起始行、终止行、起始列、终止列 起始行为1即表示表头不设置
CellRangeAddressList addressList = new CellRangeAddressList(1, 999, entry.getKey(), entry.getKey());
// 设置下拉框数据 (设置长度为0的数组会报错，所以这里需要判断)
if (entry.getValue().length > 0) {
//创建显式列表约束
DataValidationConstraint constraint = helper.createExplicitListConstraint(entry.getValue());
// 指定行列约束以及错误信息
setValidation(st,helper,constraint,addressList,"提示","请选择下拉框中的值",true);
}
}
//市区与县的级联关系
Sheet sheet = writeSheetHolder.getSheet();
Workbook book = writeWorkbookHolder.getWorkbook();
//创建隐藏的sheet
Sheet hideSheet = book.createSheet("site");
book.setSheetHidden(book.getSheetIndex(hideSheet), true);
int rowId = 0;
Row cityRow = hideSheet.createRow(rowId++);
cityRow.createCell(0).setCellValue("市区行");
//放置市数据
for (int i = 0; i < cityList.size(); i++) {
Cell proviCell = cityRow.createCell(i + 1);
proviCell.setCellValue(cityList.get(i));
}
//放置区数据
Iterator<String> keyIterator = this.cityCountyMap.keySet().iterator();
while (keyIterator.hasNext()) {
String key = keyIterator.next();
List<String> son = cityCountyMap.get(key);
Row row = hideSheet.createRow(rowId++);
row.createCell(0).setCellValue(key);
for (int i = 0; i < son.size(); i++) {
Cell cell = row.createCell(i + 1);
cell.setCellValue(son.get(i));
}
//级联数据
String range = getRange(1, rowId, son.size());
Name name = book.createName();
name.setNameName("_" + key);
String formula = "site!" + range;
name.setRefersToFormula(formula);
}
///开始设置下拉框
DataValidationHelper dvHelper = sheet.getDataValidationHelper();
// 市下拉框
DataValidationConstraint expConstraint = dvHelper.createExplicitListConstraint(cityList.toArray(new String[]{}));
CellRangeAddressList expRangeAddressList = new CellRangeAddressList(1, 999, cityIndex, cityIndex);
setValidation(sheet, dvHelper, expConstraint, expRangeAddressList, "提示", "请选择下拉框中的值",true);
// 区规则
// "INDIRECT($A$" + 2 + ")" 表示规则数据会从名称管理器中获取key与单元格 A2 值相同的数据，如果A2是浙江省，那么此处就是浙江省下面的市
// 为了让每个单元格的公式能动态适应，使用循环挨个给公式。
// 循环几次，就有几个单元格生效，次数要和上面的大类影响行数一一对应，要不然最后几个没对上的单元格实现不了级联
for (int i = 2; i < 1000; i++) {
CellRangeAddressList rangeAddressList = new CellRangeAddressList(i-1 , i-1, countyIndex, countyIndex);
DataValidationConstraint formula = dvHelper.createFormulaListConstraint("INDIRECT(\"_\"&$"+getExcelColumn(countyIndex-1)+"$"+i+")");
setValidation(sheet, dvHelper, formula, rangeAddressList, "提示", "请选择下拉框中的值",false);
}
}代码过程说明：
1.创建一个隐藏的级联site表
想看隐藏sheet，只需true改为false
java
Sheet hideSheet = book.createSheet("site");
book.setSheetHidden(book.getSheetIndex(hideSheet), true);
2.创建名称管理器
- 以市为key，即为名称管理器的名称
踩坑： 如果key为数字，则会提示名称管理器的名称不能以数字开头； 解决方案：数字前加下划线"_"
踩坑:
如果key为数字，则会提示名称管理器的名称不能以数字开头;
解决方案：数字前加下划线"_"，此时"INDIRECT"函数中必须加前缀: "下划线"&，而且下划线必须用双引号！！
java
String range = getRange(1, rowId, son.size());
Name name = book.createName();
name.setNameName("_" + key);
String formula = "site!" + range;
name.setRefersToFormula(formula);
3.填充级联数据
- 1000代表1000行生效级联关系，可自行修改。
java
for (int i = 2; i < 1000; i++) {
CellRangeAddressList rangeAddressList = new CellRangeAddressList(i-1 , i-1, countyIndex, countyIndex);
DataValidationConstraint formula = dvHelper.createFormulaListConstraint("INDIRECT(\"_\"&$"+getExcelColumn(countyIndex-1)+"$"+i+")");
setValidation(sheet, dvHelper, formula, rangeAddressList, "提示", "请选择下拉框中的值",false);
}- 工具类：
计算区域方法：
java
/**
* @param offset 偏移量，如果给0，表示从A列开始，1，就是从B列
* @param rowId 第几行
* @param colCount 一共多少列
* @return 如果给入参 1,1,10. 表示从B1-K1。最终返回 $B$1:$K$1
*/
public String getRange(int offset, int rowId, int colCount) {
char start = (char) ('A' + offset);
if (colCount <= 25) {
char end = (char) (start + colCount - 1);
return "$" + start + "$" + rowId + ":$" + end + "$" + rowId;
} else {
char endPrefix = 'A';
char endSuffix = 'A';
if ((colCount - 25) / 26 == 0 || colCount == 51) {// 26-51之间，包括边界（仅两次字母表计算）
if ((colCount - 25) % 26 == 0) {// 边界值
endSuffix = (char) ('A' + 25);
} else {
endSuffix = (char) ('A' + (colCount - 25) % 26 - 1);
}
} else {// 51以上
if ((colCount - 25) % 26 == 0) {
endSuffix = (char) ('A' + 25);
endPrefix = (char) (endPrefix + (colCount - 25) / 26 - 1);
} else {
endSuffix = (char) ('A' + (colCount - 25) % 26 - 1);
endPrefix = (char) (endPrefix + (colCount - 25) / 26);
}
}
return "$" + start + "$" + rowId + ":$" + endPrefix + endSuffix + "$" + rowId;
}
}计算列编码：
java
private static String getExcelColumn(int num) {
String column = "";
int len = alphabet.length - 1;
int first = num / len;
int second = num % len;
if (num <= len) {
column = alphabet[num] + "";
} else {
column = alphabet[first - 1] + "";
if (second == 0) {
column = column + alphabet[len] + "";
} else {
column = column + alphabet[second - 1] + "";
}
}
return column;
}