Android 按button顯示AlertDialog造成程式閃退，求大佬解答。

要做一個登入偵測是否有空白phone或password
第一次按下去會成功顯示
如果還是空白再按一次程式就會閃退
請問要怎麼辦呢?

private TextView title,msg;
        title = new TextView(this);
        title.setText("Alert");
        title.setPadding(10, 10, 10, 10);
        title.setGravity(Gravity.CENTER);
        title.setTextSize(23);

        msg = new TextView(this);
        msg.setText("Please enter your phone number");
        msg.setPadding(10, 10, 10, 10);
        msg.setGravity(Gravity.CENTER);
        msg.setTextSize(18);
 Button  nextPageLogin = (Button)findViewById(R.id.login);
        nextPageLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if("".equals(Phone.getText().toString().trim())){
                    new AlertDialog.Builder(MainActivity.this)
                            .setCustomTitle(title)
                            .setView(msg)
                            .setPositiveButton("OK", null)
                            .setCancelable(true)
                            .show();
                }else if("".equals(Password.getText().toString().trim())){
                    msg.setText("Please enter your password");
                    new AlertDialog.Builder(MainActivity.this)
                            .setCustomTitle(title)
                            .setView(msg)
                            .setPositiveButton("OK", null)
                            .setCancelable(true)
                            .show();
                }
                else{
                    Intent intent = new Intent();
                    intent.setClass(MainActivity.this,MainActivity3.class);
                    startActivity(intent);}

            }
        });
    }
        ```

Phone PassWord是什么？

你可以看看报错的日志，log里会报问题在哪里

new AlertDialog.Builder(MainActivity.this)
                        .setPositiveButton("OK", null)
                        .setView(msg)
                        .setCustomTitle(title)
                        .setCancelable(true)
                        .setOnDismissListener(new DialogInterface.OnDismissListener() {
                            @Override
                            public void onDismiss(DialogInterface dialogInterface) {
                                ((ViewGroup) title.getParent()).removeView(title);
                                ((ViewGroup) msg.getParent()).removeView(msg);
                            }
                        })
                        .show();

或者将两个TextView初始化放在点击事件里面也是可以的