Question

我们的应用程序的用户应该能够调整浮点数。目前，我在ArrayAdapter中填充了所有可能的值并将其附加到微调器上。

这个解决方案并不能满足我们的期望，因为微调器下拉框太高了。有没有更好的办法？我在看Numberpicker - 但这似乎只适用于Integer值。

有什么想法吗？

谢谢！

Answer 1

NumberPicker不仅适用于整数..即使您可以使用Floats String等。

请参阅this并阅读相关内容。

教程：

http://gafurbabu.wordpress.com/2012/03/29/android-number-picker-dialog/

我很久以前就像这样使用了NumberPicker，这可能会在这里发布：

    NumberPicker np;
    String nums[]= {"Select Fraction","1/64","1/32","3/64","1/16","5/64","3/32","7/64","1/8","9/64","5/32","11/64","3/16","13/64","7/32","15/64","1/4","17/64","9/32","19/64","5/16","21/64","11/32","23/64","3/8","25/64","13/32","27/64","7/16","29/64"};

            np = (NumberPicker) findViewById(R.id.np);

            np.setMaxValue(nums.length-1);
            np.setMinValue(0);
            np.setWrapSelectorWheel(false);
            np.setDisplayedValues(nums);
            np.setDescendantFocusability(NumberPicker.FOCUS_BLOCK_DESCENDANTS);

您可以制作任何数据类型的ArrayList并分配它。

Answer 2

另一种解决方案是将两个数字字段合并到一个组件中。请参阅Money Picker Example。它的优点是您不必为您的微调器初始化所有可能的双精度值。

您可能还需要附加特殊数字格式，例如＆＃34; 00＆＃34; ，＆＃34; 0123＆＃34; 或其他，使用java.lang.String.format()函数。示例是here。

添加双选择器xml-layout：

<LinearLayout
  xmlns:android = "http://schemas.android.com/apk/res/android"
  android:layout_width = "fill_parent"
  android:layout_height = "wrap_content"
  android:gravity = "center">

  <NumberPicker
    android:id = "@+id/integer_picker"
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    android:layout_gravity = "center"/>

  <TextView
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    android:layout_gravity = "center"
    android:padding = "5dp"
    android:text = "@string/local_separator"
    android:textSize = "20sp"/>

  <NumberPicker
    android:id = "@+id/fraction_picker"
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    android:layout_gravity = "center"/>

  <TextView
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    android:layout_gravity = "center"
    android:padding = "5dp"
    android:text = "@string/measure_unit_sign"
    android:textSize = "20sp"/>

</LinearLayout>

添加自定义双选择器类：

import android.content.Context;
import android.view.LayoutInflater;
import android.widget.NumberPicker;

/**
 * UI component for double (floating point) values. Can be used
 * for money and other measures.
 */
public class DoublePicker
  extends NumberPicker {

  private int decimals;
  private NumberPicker integerPicker;
  private NumberPicker fractionPicker;

  public DoublePicker(
    Context context) {

    super(
      context);

      LayoutInflater
        .from(
          context)
        .inflate(
          R.layout.double_picker,
          this);

      integerPicker =
        (NumberPicker) findViewById(
          R.id.integer_picker);

      fractionPicker =
        (NumberPicker) findViewById(
          R.id.fraction_picker);
  }

  public int getDecimals() {

    return decimals;
  }

  /**
   * Sets the amount of digits after separator.
   *
   * @param decimals Anount of decimals.
   */
  public void setDecimals(final int decimals) {

    this.decimals = decimals;

    this.setFormatter(new DoublePicker.Formatter() {

      @Override
      public String format(int i) {

        return String.format(
          "%." + decimals + "f",
          i);
      }
    });
  }

  public void setValue(double value) {

    integerPicker.setValue((int) value);

    fractionPicker.setValue(
      Integer.valueOf(
        String
          .valueOf(value)
          .split(".")
          [1]));
  }
}

在您的活动xml中使用新的双选择器组件：

<com.example.DoublePicker
  android:id ="@+id/double_picker"
  android:layout_width ="match_parent"
  android:layout_height ="wrap_content" />

Answer 3

在科特林中，您可以使用此方便的NumberPicker扩展对话框，将您的Double值缩放到合适的Int范围并转换{{1} }值会返回Int，然后再调用任何回调。因此，它基本上掩盖了Double仅支持NumberPicker的事实。只是感觉Int实际上会支持NumberPicker，请尝试一下！

这是片段扩展名，您需要复制并粘贴：

Double

现在您可以像这样（在fun Fragment.showNumberPickerDialog( title: String, value: Double, range: ClosedRange<Double>, stepSize: Double, formatToString: (Double) -> String, valueChooseAction: (Double) -> Unit ) { val numberPicker = NumberPicker(context).apply { setFormatter { formatToString(it.toDouble() * stepSize) } wrapSelectorWheel = false minValue = (range.start / stepSize).toInt() maxValue = (range.endInclusive / stepSize).toInt() this.value = (value.toDouble() / stepSize).toInt() // NOTE: workaround for a bug that rendered the selected value wrong until user scrolled, see also: https://stackoverflow.com/q/27343772/3451975 (NumberPicker::class.java.getDeclaredField("mInputText").apply { isAccessible = true }.get(this) as EditText).filters = emptyArray() } MaterialAlertDialogBuilder(context) .setTitle(title) .setView(numberPicker) .setPositiveButton("OK") { _, _ -> valueChooseAction(numberPicker.value.toDouble() * stepSize) } .setNeutralButton("Cancel") { _, _ -> /* do nothing, closes dialog automatically */ } .show() }中使用：

Fragment

android numberpicker用于浮点数

3 个答案: