android - 如何使用 kotlin 在 EditText 中设置输入类型和格式？

Question

我想强制用户输入一个数字，我正在使用它(并且工作正常):

android:inputType="number"

我想强制用户只输入两个数字(Int 或 Double 无关紧要)并且这些数字必须介于 0 和 20(或 0.0 和 20.0)之间:例如:0 或 0.01 或 1.5(1.0 等)...20 或 20.0

Answer 1

这是我喜欢这样做的方式:

添加这个用于编辑文本

 android:inputType="numberDecimal"  

(或)

android:digits="0123456789."

Kotlin ::

class InputFilterMinMax(min:Float, max:Float): InputFilter {
    private var min:Float = 0.0F
    private var max:Float = 0.0F

    init{
        this.min = min
        this.max = max
    }

    override fun filter(source:CharSequence, start:Int, end:Int, dest: Spanned, dstart:Int, dend:Int): CharSequence? {
        try
        {
            val input = (dest.subSequence(0, dstart).toString() + source + dest.subSequence(dend, dest.length)).toFloat()
            if (isInRange(min, max, input))
                return null
        }
        catch (nfe:NumberFormatException) {}
        return ""
    }

    private fun isInRange(a:Float, b:Float, c:Float):Boolean {
        return if (b > a) c in a..b else c in b..a
    }
}

然后在您的 EditText 上设置过滤器:

myEditText.setFilters(arrayOf<InputFilter>(InputFilterMinMax(0.0F, 20.0F)))

Java:

public class InputFilterMinMax implements InputFilter {
    private float min;
    private float max;

    public InputFilterMinMax(float min, float max) {
        this.min = min;
        this.max = max;
    }

    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
        //noinspection EmptyCatchBlock
        try {
            float input = Float.parseFloat(dest.subSequence(0, dstart).toString() + source + dest.subSequence(dend, dest.length()));
            if (isInRange(min, max, input))
                return null;
        } catch (NumberFormatException nfe) { }
        return "";
    }

    private boolean isInRange(float a, float b, float c) {
        return b > a ? c >= a && c <= b : c >= b && c <= a;
    }
}

然后在您的 EditText 上设置过滤器:

myEditText.setFilters(new InputFilter[]{new InputFilterMinMax(0.0, 20.0)});