如何在开始时默认设置选项卡并在选择选项卡时设置图标颜色

Question

我正在使用标签布局和框架布局。

• 我有五个标签。
• 我正在将我的片段加载到此框架布局中。
• 我希望我的第二个选项卡始终默认被选中。

此外，当我选择特定选项卡时，图标应将颜色更改为红色（我使用的是黑色的 png 图标，它们是否可以将它们更改为红色以表明它已被选中）

xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.TabLayout
    android:id="@+id/simple_tab_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabBackground="@color/colorWhite"
    app:tabIndicatorColor="#f00"
    app:tabSelectedTextColor="#f00"
    app:tabTextColor="#000"
    />


<FrameLayout
    android:id="@+id/fl_home"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</FrameLayout>

</LinearLayout>

这是我的 MainActivity

     pb.setIcon(R.drawable.p_icon); // pb is my  TabLayout.Tab
    mb.setIcon(R.drawable.view_p_icon);
    gb.setIcon(R.drawable.c_icon);
    ptTab.setIcon(R.drawable.c_icon);


    tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {

        @Override
        public void onTabSelected(TabLayout.Tab tab)
        {
            switch (tab.getPosition()) {
                case 0:
                    getSupportFragmentManager().beginTransaction().replace(R.id.fl_home, new UF()).commit();
                    break;
                case 1:
                    //getSupportFragmentManager().beginTransaction().replace(R.id.fl_home, new DF()).commit();
                    showAlertDialog("Logout?");
                    break;
                case 2:
                    //getSupportFragmentManager().beginTransaction().replace(R.id.fl_home, new SF()).commit();
                    showAlertDialog("Logout?");
                    break;
                case 3:
                    //getSupportFragmentManager().beginTransaction().replace(R.id.fl_home, new SF()).commit();
                    showAlertDialog("Logout?");
                    break;
                case 4:
                    getSupportFragmentManager().beginTransaction().replace(R.id.fl_home, new SF()).commit();
                    break;
            }
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });


}

Answer 1

在onTabSelected() 方法中添加setColorFilter 方法的代码。它会改变图像的颜色。

tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            int tabPosition = tab.getPosition();

            if (tabPosition == 0) {
                // active tabName
                imageOne.setColorFilter(getResources().getColor(R.color.redColor));
                // other deactive tabName
                imageTwo.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageThree.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageFour.setColorFilter(getResources().getColor(R.color.blackcolor));
            } else if (tabPosition == 1) {
                // active tabName
                imageTwo.setColorFilter(getResources().getColor(R.color.redColor));
                // other deactive tabName
                imageOne.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageThree.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageFour.setColorFilter(getResources().getColor(R.color.blackcolor));
            } else if (tabPosition == 2) {
                // active tabName
                imageThree.setColorFilter(getResources().getColor(R.color.redColor));
                // other deactive tabName
                imageTwo.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageOne.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageFour.setColorFilter(getResources().getColor(R.color.blackcolor));
            } else if (tabPosition == 3) {
                // active tabName
                imageFour.setColorFilter(getResources().getColor(R.color.redColor));
                // other deactive tabName
                imageTwo.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageThree.setColorFilter(getResources().getColor(R.color.blackcolor));
                imageOne.setColorFilter(getResources().getColor(R.color.blackcolor));
            }

        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {
            int tabPosition = tab.getPosition();
        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {
            int tabPosition = tab.getPosition();
        }
    });

默认选择标签。

如果与 viewPager 一起使用，则，

tabLayout = (TabLayout) findViewById(R.id.tablayout);
tabLayout.setupWithViewPager(viewpager);
viewpager.setCurrentItem(0);  // set any number of tab which you want to select by default.

如果不使用 viewPager 则，

tabLayout = (TabLayout) findViewById(R.id.tablayout);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);  // which you want to select.
tab.select(); 

希望对您有所帮助。