如何将整数设置为double?假设我有一个名为day的comboBox,它有1,2,3个元素。我想将它设置为两个小数点。如果用户选择1,它将变为1.00。我怎么能这样做?
public void actionPerformed(ActionEvent e){
String a=(String)comboBox.getSelectedItem();
//Integer b=(comboBox_1.getSelectedIndex()+1);
int day=(Integer)comboBox_2.getSelectedItem();
double bo;
DecimalFormat df = new DecimalFormat("#.##");
bo= Double.valueOf(df.format(day));
我得错误
java.lang.IllegalArgumentException: Cannot format given Object as a Number
at java.text.DecimalFormat.format(DecimalFormat.java:507)
at java.text.Format.format(Format.java:157)
at gui.User.<init>(User.java:105)
at gui.User$1.run(User.java:49)
答案 0 :(得分:1)
检查
public void actionPerformed(ActionEvent e){
String a=comboBox.getSelectedItem().toString();
//Integer b=(comboBox_1.getSelectedIndex()+1);
int day=Integer.ParseInt(comboBox_2.getSelectedItem().toString());
double bo;
DecimalFormat df = new DecimalFormat("#.##");
bo= Double.parseDouble(df.format(day));