only allow numbers android
import android.text.InputFilter
import android.text.Spanned
class NumberInputFilter : InputFilter {
override fun filter(
source: CharSequence?,
start: Int,
end: Int,
dest: Spanned?,
dstart: Int,
dend: Int
): CharSequence? {
source?.let {
val filtered = StringBuilder()
for (i in start until end) {
if (Character.isDigit(source[i])) {
filtered.append(source[i])
}
}
return filtered.toString()
}
return null
}
}
This Kotlin code creates a custom InputFilter
for an Android app that allows only numeric input. The NumberInputFilter
class implements the InputFilter
interface. Inside the filter
function, it examines the input characters and only allows digits to pass through, filtering out any non-numeric characters.