位置FloatingActionButton編程方式CoordinatorLayout

Question

中心

有一個CoordinatorLayout：

<android.support.design.widget.CoordinatorLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:id="@+id/cl_root" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 
</android.support.design.widget.CoordinatorLayout> 

問：一個人如何編程方式創建和位置在屏幕的中心FloatingActionButton？

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重要：：FloatingActionButton創建編程僅（無需張貼在那裏你在XML文件中定義它的答案）。

Answer 1

由於沒有答案的工作，一些實驗後，解決的辦法是：

((CoordinatorLayout.LayoutParams) fab.getLayoutParams()).gravity = Gravity.CENTER; 

Answer 2

使用此

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) fab.getLayoutParams(); 
lp.anchorGravity = Gravity.CENTER // or you can add Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL 
fab.setLayoutParams(lp); 

Answer 3

我想你會在這裏找到答案。

Set layout_anchor at runtime on FloatingActionButton

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) 
params.setAnchorId(View.NO_ID); 
fab.getLayoutParams(); 
fab.setLayoutParams(params); 

Answer 4

試試這個:)

<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="com.ncrypted.floatingactionbuttoncenter.MainActivity"> 


<android.support.design.widget.FloatingActionButton 
    android:id="@+id/fab" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"/> 

public class MainActivity extends AppCompatActivity { 
FloatingActionButton fab; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    fab = (FloatingActionButton) findViewById(R.id.fab); 

    CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) fab.getLayoutParams(); 
    lp.gravity = Gravity.CENTER; 
    fab.setLayoutParams(lp); 


} 

}

它的作品在我的情況:)