使用NumberPicker的OnValueChangeListener接口来监测NumberPicker值的变化。在每次值变化时，更新其他NumberPicker的最大值和最小值，以确保它们的总和始终等于预设的总值。以下是一个示例实现：

public class MainActivity extends AppCompatActivity implements NumberPicker.OnValueChangeListener {
    private NumberPicker np1, np2, np3;
    private int totalValue = 100;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        np1 = findViewById(R.id.np1);
        np2 = findViewById(R.id.np2);
        np3 = findViewById(R.id.np3);

        np1.setOnValueChangedListener(this);
        np2.setOnValueChangedListener(this);
        np3.setOnValueChangedListener(this);

        np1.setMaxValue(totalValue);
        np2.setMaxValue(totalValue - np1.getValue());
        np3.setMaxValue(totalValue - np1.getValue() - np2.getValue());
    }

    @Override
    public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
        int newTotal = newVal + np2.getValue() + np3.getValue();
        int diff = totalValue - newTotal;

        if (diff < 0) {
            // The new value exceeds the total.
            picker.setValue(oldVal);
            return;
        }

        // Update the maximum values of the other NumberPickers.
        switch (picker.getId()) {
            case R.id.np1:
                np2.setMaxValue(diff);
                np3.setMaxValue(totalValue - newVal - np2.getValue());
                break;
            case R.id.np2:
                np1.setMaxValue(diff + newVal);
                np3.setMaxValue(totalValue - np1.getValue() - newVal);
                break;
            case R.id.np3:
                np1.setMaxValue(diff + newVal + np2.getValue());
                np2.setMaxValue(totalValue - np1.getValue() - newVal);
                break;
        }
    }
}