TextField(
inputFormatters: [
//只允許輸入字母
WhitelistingTextInputFormatter(RegExp("[a-zA-Z]")),
],
),
TextField(
//只允許輸入數字
inputFormatters: [WhitelistingTextInputFormatter.digitsOnly],
),
TextField(
inputFormatters: [
//只允許輸入小數
WhitelistingTextInputFormatter(RegExp("[0-9.]")),
],
)
,
TextField(
inputFormatters: [
//限制小數位數
_MyNumberTextInputFormatter(digit:5),
],
)
// 限制小數位數
class _MyNumberTextInputFormatter extends TextInputFormatter {
static const defaultDouble = 0.001;
///允許的小數位數,-1代表不限制位數
int digit;
_MyNumberTextInputFormatter({this.digit=-1});
static double strToFloat(String str, [double defaultValue = defaultDouble]) {
try {
return double.parse(str);
} catch (e) {
return defaultValue;
}
}
///獲取目前的小數位數
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),
);
}
}
Flutter TextField 限制只允許輸入數字,字母,小數,設置限制小數位數
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