Android 简单定义底部弹窗

1、说明

我们有时需要定义底部弹窗，比如做一个分享到QQ、微信、微博的底部选择弹窗。

2、实现方法

public class SharePopWindow extends PopupWindow {

    private Activity mContext;
    private WindowManager.LayoutParams windowLayoutParams;

    public SharePopWindow(Activity context) {
        super(context);
        mContext = context;
        windowLayoutParams = context.getWindow().getAttributes();

        initView();
        initListener();
    }

    /**
     * 直接展示在屏幕底部，无需添加其它参数
     */
    public void show() {
        showAtLocation(mContext.getWindow().getDecorView(), Gravity.BOTTOM|Gravity.CENTER_HORIZONTAL, 0, 0);
        setAlpha(0.5f);
    }

    private void initView() {
        View v = View.inflate(mContext, R.layout.view_share_pop, null);
        setContentView(v);

        setWidth(ViewGroup.LayoutParams.MATCH_PARENT);
        setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
        setFocusable(true); 
        // 底部弹出动画效果
        setAnimationStyle(R.style.BottomInBottomOut);

        // 设置背景色，保证弹窗主体没有黑边
        ColorDrawable dw = new ColorDrawable(0xb0000000);
        setBackgroundDrawable(dw);
    }

    private void initListener() {
        setOnDismissListener(new OnDismissListener() {
            @Override
            public void onDismiss() {
                setAlpha(1.0f);
            }
        });
    }

    private void setAlpha(float alpha) {
        windowLayoutParams.alpha = alpha;
        mContext.getWindow().setAttributes(windowLayoutParams);
    }
}

style.xml

<resources>
    <!--底部弹窗-->
    <style name="BottomInBottomOut" parent="android:Animation">
        <item name="android:windowEnterAnimation">@anim/push_bottom_in</item>
        <item name="android:windowExitAnimation">@anim/push_bottom_out</item>
    </style>
</resources>

push_bottom_in.xml

<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="500"
        android:fromYDelta="100%p"
        android:toYDelta="0" />
</set>

push_bottom_out.xml

<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="500"
        android:fromYDelta="0"
        android:toYDelta="100%p" />
</set>

搞定 ！