• 效果如下：

  
  
  20170207111422954.png

• 引入CoordinatorLayout、FloatingActionButton、Snackbar

```
compile 'com.android.support:design:25.1.0'
```

• 布局如下：

<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="cn.hnshangyu.coordinatorlayout.MainActivity">

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right|bottom"
        android:layout_margin="20dp"
        android:src="@mipmap/ic_launcher" />
</android.support.design.widget.CoordinatorLayout>

CoordinatorLayout作为“super-powered FrameLayout”，设置子视图的Android:layout_gravity属性控制位置。

• 在activity中：

package cn.hnshangyu.coordinatorlayout;

import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private FloatingActionButton fab;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
//                Snackbar.make(view,"弹出来了，哈哈",Snackbar.LENGTH_INDEFINITE)
//                        .show();
                Snackbar.make(view,"弹出来了，哈哈",Snackbar.LENGTH_INDEFINITE)
                        .setAction("取消", new View.OnClickListener() {
                            @Override
                            public void onClick(View view) {
                                Toast.makeText(MainActivity.this,"点击消除Action后的响应事件",Toast.LENGTH_LONG)
                                        .show();
                            }
                        })
                        .show();
            }
        });
    }
}

如果想使用FloatingActionButton与ListView, RecyclerView 和 ScrollView等一起使用，请看：http://blog.csdn.net/huangxiaoguo1/article/details/53708112