C# 警报对话框未显示

我有一个解析器，它将值作为字符串抓取，如果它不等于预期值，则调用下面的函数。只有下面的函数不做任何操作，它到达builder.show（），然后跳回我的解析器。它不会显示该对话框，因为如果显示该对话框，则在选择“确定”按钮时，它将在代理上点击finish（）。关于可能导致此问题的原因的任何想法。我不知道我是否有一些语法错误，或者是什么问题？我感谢所有的帮助

private void errorReturnReader(string val)
    {
        string message = "";
        if (val != "")
        {
            AlertDialog.Builder builder;
            builder = new AlertDialog.Builder (this,3);
            builder.SetTitle("Institution Status Error");
            builder.SetCancelable(false);
            builder.SetPositiveButton("OK", delegate { Finish(); });

            switch (val)
            {
            case "NO_KEY":
                message = "The Key passed does not exist.";
                break;
            case "NO_EMP":
                message = "The employee id does not exist in the specified institution.";
                break;
            case "NO_INST":
                message = "The Institution code associated with key does not exist.";
                break;
            case "NO_BRANCH":
                message = "The Branch value passed does not exist.";
                break;
            case "EMP_EXCL":
                message = "Employee is excluded from all branches.";
                break;
            case "NO_STAT":
                message = "No audit records were found for the branch.";
                break;
            case "NO_RESPONSE":
                message = "No status was returned";
                break;
            case "NO_COMM":
                message = "The Cloud has not communicated with the Console within 60 seconds. Can not verify status.";
                break;
            default:
                break;
            }
            builder.SetMessage(message);
            builder.Create ();
            builder.Show ();
        }
    }

---

对于字符串比较，请使用

.equals（）

，即。 改变

到

或

有关更多信息，请参阅

同时要显示对话框，请更改

 builder.Create ();
 builder.Show ();

到

---

有关更多信息，请参见

尝试以下操作：builder.Create（）.show（）；我在发帖前也试过了，结果没有改变。我感谢你的答复。

 if (!"".equals(val))

 if (val.length() != 0)

 builder.Create ();
 builder.Show ();

 builder.create().show();