Flutter TextField 限制只允许输入数字,字母,小数,设置限制小数位数
2023-09-14 09:04:26 时间
TextField(
inputFormatters: [
//只允许输入字母
WhitelistingTextInputFormatter(RegExp("[a-zA-Z]")),
],
),
TextField(
//只允许输入数字
inputFormatters: [WhitelistingTextInputFormatter.digitsOnly],
),
TextField(
inputFormatters: [
//只允许输入小数
WhitelistingTextInputFormatter(RegExp("[0-9.]")),
],
)
,
TextField(
inputFormatters: [
//限制小数位数
_MyNumberTextInputFormatter(digit:5),
],
)
// 限制小数位数
class _MyNumberTextInputFormatter extends TextInputFormatter {
static const defaultDouble = 0.001;
///允许的小数位数,-1代表不限制位数
int digit;
_MyNumberTextInputFormatter({this.digit=-1});
static double strToFloat(String str, [double defaultValue = defaultDouble]) {
try {
return double.parse(str);
} catch (e) {
return defaultValue;
}
}
///获取目前的小数位数
static int getValueDigit(String value){
if(value.contains(".")){
return value.split(".")[1].length;
}else{
return -1;
}
}
@override
TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
String value = newValue.text;
int selectionIndex = newValue.selection.end;
if (value == ".") {
value = "0.";
selectionIndex++;
} else if (value != ""
&& value != defaultDouble.toString()
&& strToFloat(value, defaultDouble) == defaultDouble
||getValueDigit(value)>digit) {
value = oldValue.text;
selectionIndex = oldValue.selection.end;
}
return new TextEditingValue(
text: value,
selection: new TextSelection.collapsed(offset: selectionIndex),
);
}
}