AlertDialog点击确定不消失

AlertDialog alertDialog = new AlertDialog.Builder(this)
                    .setTitle("标题")
                    .setMessage("内容")
                    .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            
                        }
                    })
                    .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            
                        }
                    })
                    .show();

          //创建输入框
          EditText et = new EditText(this);
          AlertDialog alertDialog = new AlertDialog.Builder(this).setTitle("备注")
                  .setMessage("经度：" + lng + "纬度：" + lat)
                  //添加输入框
                  .setView(et)
                  .setPositiveButton("确定", null)
                  .setNegativeButton("取消", null)
                  .show();
          //拿到按钮并判断是否是POSITIVEBUTTON，然后我们自己实现监听
          alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  String input = et.getText().toString();
                  if (input.equals("")) {
                      Toast.makeText(getApplicationContext(), "内容不能为空！" + input, Toast.LENGTH_LONG).show();
                      return;
                  } else {
                      //让AlertDialog消失
                      alertDialog.cancel();
                  }
              }
          });