有没有一种方法可以在Android中为EditText定义最小值和最大值? [英] Is there a way to define a min and max value for EditText in Android?

问题描述

我想为EditText定义一个最小值和最大值.

例如:如果有人尝试在其中输入月份值，则该值必须在1到12之间.

我可以使用TextWatcher来做到这一点，但我想知道布局文件或其他地方是否还有其他方法可以实现.

我不想限制字符数.我想限制值.例如，如果我在输入12时限制月份EditText w个字符，它将接受它，但是如果输入22，它在输入时一定不能接受.

解决方案

首先创建此类:

package com.test;

import android.text.InputFilter;
import android.text.Spanned;

public class InputFilterMinMax implements InputFilter {

    private int min, max;

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

    public InputFilterMinMax(String min, String max) {
        this.min = Integer.parseInt(min);
        this.max = Integer.parseInt(max);
    }

    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {   
        try {
            int input = Integer.parseInt(dest.toString() + source.toString());
            if (isInRange(min, max, input))
                return null;
        } catch (NumberFormatException nfe) { }     
        return "";
    }

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

然后在活动"中使用它:

EditText et = (EditText) findViewById(R.id.myEditText);
et.setFilters(new InputFilter[]{ new InputFilterMinMax("1", "12")});

这将允许用户仅输入1到12之间的值.

使用android:inputType="number"设置您的编辑文本.

您可以在 https://www.techcompose.com/how-to-set-minimum-and-maximum-value-in-edittext-in-android-app-develop-/.

谢谢.

I want to define a min and max value for an EditText.

For example: if any person tries to enter a month value in it, the value must be between 1-12.

I can do it by using TextWatcher but I want to know if there is any other way to do it in layout file or elsewhere.

Edit: I don't want to limit character count. I want to limit the value. For example, if I limit month EditText w characters when I enter 12 it will accept it but if I enter 22 it mustn't accept it while I am entering.

解决方案

First make this class :

package com.test;

import android.text.InputFilter;
import android.text.Spanned;

public class InputFilterMinMax implements InputFilter {

    private int min, max;

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

    public InputFilterMinMax(String min, String max) {
        this.min = Integer.parseInt(min);
        this.max = Integer.parseInt(max);
    }

    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {   
        try {
            int input = Integer.parseInt(dest.toString() + source.toString());
            if (isInRange(min, max, input))
                return null;
        } catch (NumberFormatException nfe) { }     
        return "";
    }

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

Then use this from your Activity :

EditText et = (EditText) findViewById(R.id.myEditText);
et.setFilters(new InputFilter[]{ new InputFilterMinMax("1", "12")});

This will allow user to enter values from 1 to 12 only.

EDIT :

Set your edittext with android:inputType="number".

You can find more details at https://www.techcompose.com/how-to-set-minimum-and-maximum-value-in-edittext-in-android-app-development/.

Thanks.

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