Java for loop try语句使用jxcelapi将EXCEL数据添加到SD卡

我被难住了……：( 用一个更简单的循环进行测试，但仍然只写一个单元格…第一个。 有人能解释为什么在循环中它完美地写入log.d，而addcell没有

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    String Fnamexls="testfile"  + ".xls";
    File sdCard = Environment.getExternalStorageDirectory();
    File directory = new File (sdCard.getAbsolutePath() + "/Lottery");
    directory.mkdirs();
    File file = new File(directory, Fnamexls);

    WorkbookSettings wbSettings = new WorkbookSettings();

    wbSettings.setLocale(new Locale("en", "EN"));

    WritableWorkbook workbook;
    try {

        workbook = Workbook.createWorkbook(file, wbSettings);
        workbook.createSheet("Report", 0);
        sheet = workbook.createSheet("First Sheet", 0);

循环应该在try函数中

        for (int a =0;a<10;a++){

            test = a;
            label4 = new Label(0,test,String.valueOf(test));

            try {
                sheet.addCell(label4);
                Log.d("log1","a: "+a+" test:  "+test);

            } catch (RowsExceededException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (WriteException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            workbook.write();
        }
        try {
            workbook.close();
        } catch (WriteException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //createExcel(excelSheet);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

for（int a=0；aI被难住了……：（为测试编写了一个更简单的循环，但仍然只写入一个单元格…第一个。有人能解释一下为什么在llop中它完美地写入log.d，而addcell没有………我被难住了……：（为测试编写了一个更简单的循环，但仍然只写入一个单元格…第一个。有人能解释一下为什么在llop中它完美地写入log.d，而addcell没有。。。。。