直接上代码

public class ToastUtil {
    private Toast mToast;
    private TextView mTextView;
    private TimeCount timeCount;
    private String message;
    private Handler mHandler = new Handler();
    private boolean canceled = true;

    public ToastUtil(Context context, int layoutId, String msg) {
        message = msg;
        LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        //自定义布局
        View view = inflater.inflate(layoutId, null);
        //自定义toast文本
        mTextView = (TextView)view.findViewById(R.id.tvToast);
        mTextView.setText(msg);
        Log.i("ToastUtil", "Toast start...");
        if (mToast == null) {
            mToast = new Toast(context);
            Log.i("ToastUtil", "Toast create...");
        }
        //设置toast居中显示
        mToast.setGravity(Gravity.BOTTOM, 0, 85);
        mToast.setDuration(Toast.LENGTH_LONG);
        mToast.setView(view);
    }

    /**
     * 自定义居中显示toast
     */
    public void show() {
        mToast.show();
        Log.i("ToastUtil", "Toast show...");
    }

    /**
     * 自定义时长、居中显示toast
     * @param duration
     */
    public void show(int duration) {
        timeCount = new TimeCount(duration, 1000);
        Log.i("ToastUtil", "Toast show...");
        if (canceled) {
            timeCount.start();
            canceled = false;
            showUntilCancel();
        }
    }

    /**
     * 隐藏toast
     */
    private void hide() {
        if (mToast != null) {
            mToast.cancel();
        }
        canceled = true;
        Log.i("ToastUtil", "Toast that customed duration hide...");
    }

    private void showUntilCancel() {
        if (canceled) { //如果已经取消显示，就直接return
            return;
        }
        mToast.show();
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                Log.i("ToastUtil", "Toast showUntilCancel...");
                showUntilCancel();
            }
        }, Toast.LENGTH_LONG);
    }

    /**
     *  自定义计时器
     */
    private class TimeCount extends CountDownTimer {

        public TimeCount(long millisInFuture, long countDownInterval) {
            super(millisInFuture, countDownInterval); //millisInFuture总计时长，countDownInterval时间间隔(一般为1000ms)
        }

        @Override
        public void onTick(long millisUntilFinished) {
            mTextView.setText(message + ": " + millisUntilFinished / 500 + "s后消失");
        }

        @Override
        public void onFinish() {
            hide();
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:gravity="center"
        android:layout_height="match_parent">
        <TextView
            android:paddingLeft="@dimen/dp_55"
            android:paddingRight="@dimen/dp_50"
            android:gravity="center"
            android:lineHeight="@dimen/dp_22"
            android:background="@drawable/shape_circle_solid_99_ffffff"
            android:layout_width="wrap_content"
            android:id="@+id/tvToast"
            android:textColor="#FFFFFF"
            android:textSize="@dimen/dp_25"
            android:layout_height="@dimen/dp_70"/>
    </LinearLayout>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <solid android:color="@color/custom_toast" />
    <corners android:radius="@dimen/dp_35" />
</shape>

Java调用

ToastUtil toastUtil = new ToastUtil(getBaseContext(), R.layout.view_toast_custom, getResources().getString(R.string.export_Gallery));
                            toastUtil.show();