芯片组单选

Question

如何强制 ChipGroup 像 RadioGroup 一样始终至少选择一项？设置 setSingleSelection(true) 还可以增加在 Chip.

上单击两次时不选择任何内容的可能性

Answer 1

一个解决方案是预设一个点击筹码，然后切换筹码的可点击属性:

chipGroup.setOnCheckedChangeListener((chipGroup, id) -> {
    Chip chip = ((Chip) chipGroup.getChildAt(chipGroup.getCheckedChipId()));
    if (chip != null) {
        for (int i = 0; i < chipGroup.getChildCount(); ++i) {
            chipGroup.getChildAt(i).setClickable(true);
        }
        chip.setClickable(false);
    }
});

Answer 2

对@adriennoir 的回答（在 Kotlin 中）的简要修改。谢谢您的帮助！请注意，getChildAt() 采用索引。

for (i in 0 until group.childCount) {
    val chip = group.getChildAt(i)
    chip.isClickable = chip.id != group.checkedChipId
}

这是我更大的`setOnCheckedChangeListener，用于上下文：

intervalChipGroup.setOnCheckedChangeListener { group, checkedId ->

    for (i in 0 until group.childCount) {
        val chip = group.getChildAt(i)
        chip.isClickable = chip.id != group.checkedChipId
    }

    when (checkedId) {
        R.id.intervalWeek -> {
            view.findViewById<Chip>(R.id.intervalWeek).chipStrokeWidth = 1F
            view.findViewById<Chip>(R.id.intervalMonth).chipStrokeWidth = 0F
            view.findViewById<Chip>(R.id.intervalYear).chipStrokeWidth = 0F
            currentIntervalSelected = weekInterval
            populateGraph(weekInterval)
        }
        R.id.intervalMonth -> {
            view.findViewById<Chip>(R.id.intervalWeek).chipStrokeWidth = 0F
            view.findViewById<Chip>(R.id.intervalMonth).chipStrokeWidth = 1F
            view.findViewById<Chip>(R.id.intervalYear).chipStrokeWidth = 0F
            currentIntervalSelected = monthInterval
            populateGraph(monthInterval)

        }
        R.id.intervalYear -> {
            view.findViewById<Chip>(R.id.intervalWeek).chipStrokeWidth = 0F
            view.findViewById<Chip>(R.id.intervalMonth).chipStrokeWidth = 0F
            view.findViewById<Chip>(R.id.intervalYear).chipStrokeWidth = 1F
            currentIntervalSelected = yearInterval
            populateGraph(yearInterval)
        }
    }

}

Answer 3

我是这样做的：

var previousSelection: Int = default_selection_id 
chipGroup.setOnCheckedChangeListener { chipGroup, id ->
    if (id == -1) //nothing is selected.
        chipGroup.check(previousSelection)
    else
        previousSelection = id

Answer 4

大部分答案都很棒，对我很有帮助。对@adriennoir 和@Todd DeLand 的另一个细微修改，以防止在 setSingleSelection(true) ChipGroup 中取消选中已检查的芯片，这是我的解决方案：

for (i in 0 until chipGroup.childCount) {
    val chip = chipGroup.getChildAt(i) as Chip
    chip.isCheckable = chip.id != chipGroup.checkedChipId
    chip.isChecked = chip.id == chipGroup.checkedChipId
}

对我来说，我只需要在不使其不可点击的情况下防止取消选中相同的已选中 Chip。这样，用户仍然可以点击选中的芯片并看到花哨的波纹效果，而不会发生任何事情。

Answer 5

编辑

版本 1.2.0-alpha02 不再需要旧的 hacky 解决方案！

要么使用属性 app:selectionRequired="true"


<com.google.android.material.chip.ChipGroup
            android:id="@+id/group"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:selectionRequired="true"
            app:singleSelection="true">

  (...)
</com.google.android.material.chip.ChipGroup>

或在代码中


// Kotlin
group.isSelectionRequired = true

// Java
group.setSelectionRequired(true);

旧版本

实现这个有两个步骤

第 1 步

我们有此支持 built-in，只需确保将 app:singleSelection="true" 添加到您的 ChipGroup，例如：

XML

<com.google.android.material.chip.ChipGroup
            android:id="@+id/group"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:singleSelection="true">

        <com.google.android.material.chip.Chip
                android:id="@+id/option_1"
                style="@style/Widget.MaterialComponents.Chip.Choice"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Option 1" />

        <com.google.android.material.chip.Chip
                android:id="@+id/option_2"
                style="@style/Widget.MaterialComponents.Chip.Choice"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Option 2" />
</com.google.android.material.chip.ChipGroup>

代码


// Kotlin
group.isSingleSelection = true

// Java
group.setSingleSelection(true);

第 2 步

现在支持广播组之类的功能：


var lastCheckedId = View.NO_ID
chipGroup.setOnCheckedChangeListener { group, checkedId ->
    if(checkedId == View.NO_ID) {
        // User tried to uncheck, make sure to keep the chip checked          
        group.check(lastCheckedId)
        return@setOnCheckedChangeListener
    }
    lastCheckedId = checkedId

    // New selection happened, do your logic here.
    (...)

}

来自docs：

ChipGroup also supports a multiple-exclusion scope for a set of chips. When you set the app:singleSelection attribute, checking one chip that belongs to a chip group unchecks any previously checked chip within the same group. The behavior mirrors that of RadioGroup.

Answer 6

这是我的工作解决方案

mChipGroup.setOnCheckedChangeListener((group, checkedId) -> {
            for (int i = 0; i < mChipGroup.getChildCount(); i++) {
                Chip chip = (Chip) mChipGroup.getChildAt(i);
                if (chip != null) {
                    chip.setClickable(!(chip.getId() == mChipGroup.getCheckedChipId()));
                }
            }
    });

Answer 7

为了防止所有芯片被取消选择，您可以使用方法 setSelectionRequired:

chipGroup.setSelectionRequired(true)

您也可以使用 app:selectionRequired 属性在布局中定义它：

<com.google.android.material.chip.ChipGroup
    app:singleSelection="true"
    app:selectionRequired="true"
    app:checkedChip="@id/..."
    ..>

注意：这需要最低版本1.2.0

Answer 8

如果 singleSelection 不适用于添加的动态筹码，您必须 生成 id为每个芯片创建它们然后添加到 ChipGroup.

val chip = inflater.inflate(
R.layout.item_crypto_currency_category_chip,
binding.chipGroupCryptoCurrencyCategory,
false) as Chip

chip.id = ViewCompat.generateViewId()

binding.chipGroupCryptoCurrencyCategory.addView(chip)

//Set default value with index 0 when ChipGroup created.
if (index == 0) binding.chipGroupCryptoCurrencyCategory.check(chip.id)

item_crypto_currency_category_chip.xml

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.chip.Chip xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/chip_smart_contract"
style="@style/Widget.Signal.Chip"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />

item_crypto_currency_tag_category.xml

<HorizontalScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="@dimen/spacing_6x"
    android:scrollbars="none"
    app:layout_constraintTop_toTopOf="parent">

    <com.google.android.material.chip.ChipGroup
        android:id="@+id/chip_group_crypto_currency_category"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:singleSelection="true"
        app:singleLine="true"
        />

</HorizontalScrollView>

结果：

芯片组单选

ChipGroup single selection

android

material-components

material-components-android

android-chips

编辑

旧版本

第 1 步

第 2 步