Question

我如何强迫ChipGroup像RadioGroup一样始终拥有至少一个选定项？设置setSingleSelection(true)还会增加单击Chip两次时未选择任何内容的可能性。

Answer 1

要防止取消选择所有筹码，可以使用方法 setSelectionRequired ：

chipGroup.setSelectionRequired(true)

您还可以使用 app:selectionRequired 属性在布局中对其进行定义：

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

注意：这要求最低版本为 1.2.0-alpha02

Answer 2

一种解决方案是预先设置点击的芯片，然后切换芯片的clickable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 3

@adriennoir的答案的简短修改（在Kotlin中）。谢谢您的帮助！请注意，getChildAt()需要一个索引。

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 4

有两个步骤可以实现

步骤1

我们内置了此支持，只需确保将app:singleSelection="true"添加到您的ChipGroup中，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);

步骤2

现在支持类似广播组的功能：


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还支持一组芯片的多重排除范围。设置app：singleSelection属性时，请检查一块属于芯片组的人取消选中其中任何先前检查过的芯片同一组。该行为反映了RadioGroup的行为。

Answer 5

这是我的方法：

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

Answer 6

大多数答案都很好，对我来说真的很有帮助。为了防止取消选中setSingleSelection(true) ChipGroup中已经检查过的筹码，对@adriennoir和@Todd DeLand进行了另一项轻微的修改，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，我只需要防止取消选中同一选中的Chip而不使它不可点击即可。这样，用户仍然可以单击选中的芯片并看到花哨的涟漪效应，而不会发生任何事情。

Answer 7

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 8

对于避免不必要地遍历所有ChipGroup子级的通用解决方案，请尝试以下操作...

chip_group.setOnCheckedChangeListener(object : ChipGroup.OnCheckedChangeListener {
    @IdRes
    private var lastCheckedChipId: Int = View.NO_ID

    override fun onCheckedChanged(chipGroup: ChipGroup, checkedChipId: Int) {
        chipGroup.findViewById<Chip>(checkedChipId).isClickable = false
        if (lastCheckedChipId != checkedChipId && lastCheckedChipId != -1) {
            chipGroup.findViewById<Chip>(lastCheckedChipId).isClickable = true
        }
        lastCheckedChipId = checkedChipId
    }
})

请记住在您的app:singleSelection="true"上指定ChipGroup！

更新：我观察到在销毁并重新创建屏幕后，此代码崩溃，这是由于onCheckedChange()被checkedChipId == -1（默认）调用，因此findViewById()调用返回了{{1} }。可以通过检查这种情况并尽早返回来解决：

null

ChipGroup单选

8 个答案:

步骤1

步骤2