Material Design 组件之 FloatingActionButton

CoordinatorLayout

1. 作为应用的顶层布局
2. 作为与一个或多个子 View 交互的容器

FloatingActionButton

//设置图标
fab.setImageDrawable(getResources().getDrawable(R.drawable.fab));
fab.setImageResource(R.drawable.fab);

//设置背景颜色
fab.setBackgroundTintList(ColorStateList.valueOf(Color.parseColor("#000000")));

//设置大小
fab.setSize(FloatingActionButton.SIZE_MINI);

//源码
private int getSizeDimension(@Size final int size) {
    final Resources res = getResources();
    switch (size) {
        case SIZE_AUTO:
            // If we're set to auto,grab the size from resources and refresh
            final int width = res.getConfiguration().screenWidthDp;
            final int height = res.getConfiguration().screenHeightDp;
            return Math.max(width,height) < AUTO_MINI_LARGEST_SCREEN_WIDTH
                    ? getSizeDimension(SIZE_MINI)
                    : getSizeDimension(SIZE_NORMAL);
        case SIZE_MINI:
            return res.getDimensionPixelSize(R.dimen.design_fab_size_mini);
        case SIZE_NORMAL:
        default:
            return res.getDimensionPixelSize(R.dimen.design_fab_size_normal);
    }
}

/**dimens.xml**/
<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools">
    <dimen name="design_fab_size_mini" tools:override="true">20dp</dimen>
    <dimen name="design_fab_size_normal" tools:override="true">100dp</dimen>
</resources>

FloatingActionButton 的属性

android:src             //设置图标(24dp)
app:backgroundTint      //设置图标背景颜色。  
app:rippleColor         //设置点击时水波纹颜色  
app:elevation           //设置阴影大小
app:fabSize             //设置大小 
app:pressedTranslationZ //按下时距离Z轴的距离  
app:layout_anchor       //设置锚点  
app:layout_anchorGravity//设置相对锚点的位置

简单使用

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.manu.materialdesignsamples.samples.SampleActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rvData"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="12dp"
        android:layout_marginEnd="12dp"
        android:visibility="visible"/>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="12dp"
        android:layout_gravity="bottom|end"
        android:src="@drawable/fab"
        android:scaleType="center"
        app:backgroundTint="@color/colorAccent"
        app:backgroundTintMode="src_in"
        app:elevation="5dp"
        app:rippleColor="#000000"
        app:fabSize="auto"
        app:pressedTranslationZ="10dp"/>

</android.support.design.widget.CoordinatorLayout>

findViewById(R.id.fab).setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Snackbar.make(v,"我是Snackbar...",Snackbar.LENGTH_SHORT)
                .setAction("取消",new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Toast.makeText(SampleActivity.this,"取消",Toast.LENGTH_SHORT).show();
                    }
                }).show();
    }
});