Android自定義懸浮按鈕效果實現，帶移動效果

一個帶動畫效果的懸浮按鈕。從下往上顯示，從上往下消失。

代碼比較簡單，實現原理也比較簡單。

public class MainActivity extends Activity {
    private Button btn_hide,btn_show;
    private Floatingbutton floatingButton ;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         btn_hide=(Button)findViewById(R.id.btn_hide);
            btn_show=(Button)findViewById(R.id.btn_show);
             floatingButton = (Floatingbutton) findViewById(R.id.button_floating_action);
            btn_hide.setOnClickListener(new OnClickListener() {


            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                 floatingButton.hide();
            }
        });

        btn_show.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                 floatingButton.show();
            }
        });
}

}
public class Floatingbutton extends ImageButton {
    private Boolean isShow = false;
     private static final int TRANSLATE_DURATION_MILLIS = 200;
    private final Interpolator mInterpolator = new AccelerateDecelerateInterpolator();
    public Floatingbutton(Context context) {
        super(context);
    }
    public Floatingbutton(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }
    public Floatingbutton(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs);
    }
    public void init(Context context, AttributeSet attrs) {
        show();
    }
    public void show() {
        if (!isShow) {
            isShow = true;
            toggle();
        }

}
public void hide() {
    if (isShow) {
        isShow = false;
        toggle();
    }

}
private void toggle() {
      int height = getHeight();
      int translationY = isShow ? 0 : height + getMarginBottom();
      animate().setInterpolator(mInterpolator)
      .setDuration(TRANSLATE_DURATION_MILLIS)
      .translationY(translationY);
}
private int getMarginBottom() {
    int marginBottom = 0;
    final ViewGroup.LayoutParams layoutParams = getLayoutParams();
    if (layoutParams instanceof ViewGroup.MarginLayoutParams) {
        marginBottom = ((ViewGroup.MarginLayoutParams) layoutParams).bottomMargin;
    }
    return marginBottom;
}

}
</pre>