Bottom navigation view - gradient icon tint

问题

I have changed icon tint in BottomNavigationView using selector and gradient color as tint when icon is pressed, but instead changing icon tint to gradient Android made all my icon purple. My question is if there is any possibility to change tint of icons in BottomNavigationView to be gradient color?

BottomNavigationCode:

<com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/nav_bottom_main"
        android:layout_width="match_parent"
        app:itemIconTint="@color/bottom_menu_background"
        android:layout_height="wrap_content"
        app:menu="@menu/bottom_navigation_main"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

bottom_menu_background:

 <?xml version="1.0" encoding="utf-8"?>
 <selector xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:color="@color/button_gradient_blue" android:state_checked="true" />
     <item android:color="@color/baseGray"/>
 </selector>

button_gradient_blue:

<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_pressed="true" >
        <shape android:shape="rectangle"  >
            <corners android:radius="@dimen/base_button_radius" />
            <gradient android:angle="0" android:startColor="@color/light_blue_gradient_start"
            android:endColor="@color/light_blue_gradient_end"  />
        </shape>
    </item>
    <item android:state_focused="true">
        <shape android:shape="rectangle"  >
            <corners android:radius="@dimen/base_button_radius" />
            <solid android:color="@color/button_pressed_color"/>
        </shape>
    </item>
    <item >
        <shape android:shape="rectangle"  >
            <corners android:radius="@dimen/base_button_radius" />
            <gradient android:angle="0" android:startColor="@color/light_blue_gradient_start"
            android:endColor="@color/light_blue_gradient_end" />
        </shape>
    </item>
</selector>

回答1:

A more simple way to achieve this than creating a subclass, is to create two separate drawables, then creating a selector which is assigned as the icon for the menu for the bottom navigation view.

activity.xml:

<android.support.design.widget.BottomNavigationView
    android:id="@+id/navigation"
    app:itemIconTint="@drawable/sel_navigation"
    app:itemTextColor="@drawable/sel_navigation_label"
    app:menu="@menu/navigation" />

menu/navigation.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
    android:id="@+id/navigation_history"
    android:icon="@drawable/ic_history_selector"
    android:title="@string/title_history" />
</menu>

drawable/ic_history_selector.xml:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/ic_history_selected" android:state_pressed="true" />
<item android:drawable="@drawable/ic_history_selected" android:state_checked="true"/>
<item android:drawable="@drawable/ic_history"/>
</selector>

drawable/ic_history.xml:

<vector ...>
<path android:fillColor="@color/gradient_orange" .../>
</vector>

color/gradient_orange.xml:

<gradient xmlns:android="http://schemas.android.com/apk/res/android"
android:angle="0"
android:endColor="@color/orange"
android:startColor="@color/lightOrange"
android:startX="0"
android:endX="0"
android:startY="0"
android:endY="100"
android:type="linear" />

Finally in the activity you need to set the icon tint list to null, so it won't use the icon tint color from the xml. Works perfectly with gradients (API 24+).

See: https://stackoverflow.com/a/47203888

回答2:

Solution:

First and foremost, Use the below given BottomNavigationView

<android.support.design.widget.BottomNavigationView
    android:id="@+id/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    app:itemBackground="@color/White"
    app:itemIconTint="@color/bottom_color"
    app:itemTextColor="@color/bottom_color"
    app:menu="@menu/your_menu_layout"/>

then, make a folder called color (if you do not have already), then make a file called bottom_color then use app:itemIconTint="@color/bottom_color" file below:

bottom_color

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:color="@color/Black"
        android:state_checked="false"/>
    <item
        android:color="#1c5fab"
        android:state_checked="true"/>

</selector>

You can give whatever color you want in android:state_checked="true"

This is from my own project, which I'm using.

Try it. Hope it helps.

回答3:

Ok I managed to do this by using two different drawables, one with gradient tint and one for unselected in Bottom Navigation Menu.

I have created custom view that extends form BottomNavigationView, and I have created custom method for creating menu:

fun initMenu(){
    itemIconTintList = null
    var firstStart = true
    setOnNavigationItemSelectedListener {
        val index = it.itemId
        firstStart = false
        menu.forEach {
            if (it.isChecked && !firstStart) {
                if (it.itemId == index)
                    return
                it.isChecked = false
                it.icon = ContextCompat
                    .getDrawable(context, UNSELECTED_MAP[it.itemId]!!)
        }

    }
    it.icon = ContextCompat.getDrawable(context, SELECTED_MAP[it.itemId]!!)

}

Where UNSELECTED_MAP and SELECTED MAP are a HashMaps with item menu id as "key" and drawable resource as "value"

回答4:

set color in java bottomNav.addItemNav(new ItemNav(this, R.drawable.ic_home, getResources().getString(R.string.home)).addColorAtive(R.color.yellow_selected_color).addColorInative(R.color.text_color));

来源：https://stackoverflow.com/questions/52420262/bottom-navigation-view-gradient-icon-tint