Toast的连续弹出

连续弹出Toast时，系统会默认一个个弹出，会造成触发了之后很久才会有这个Toast的出现。下边的代码可以解决这个问题：

public class ToastUtil {
    private static Toast toast;

    public static void show(String text) {
        if (toast != null) {
            toast.cancel();
        }
        toast = Toast.makeText(App.getContext(), text, Toast.LENGTH_SHORT);
        toast.show();
    }

    public static void showLong(String text) {
        if (toast != null) {
            toast.cancel();
        }
        toast = Toast.makeText(App.getContext(), text, Toast.LENGTH_LONG);
        toast.show();
    }
}