如何关注Angular 2中新增的输入？

Question

我的模板

 static void Upload()
    {
        int count = 0;
        string connstring = "Data Source=(local);Initial Catalog=Images;Persist Security Info=True;User ID=test;Password=testpassword";

        DataTable dtconnection = Query("Select ConnectionString from IT.Connection where isnull(ConnectionString,'')!=''", connstring);
        foreach (DataRow dtcon in dtconnection.Rows)
        {

            DataTable convimage = Query("Select Keyfield,Path from dbo.ConvertedImage where isnull(Path,'')!='' and ISNULL(ConvertedImage,'')='' ", dtcon[0].ToString());

            foreach (DataRow dtrow in convimage.Rows)
            {
                count++;
                Console.WriteLine("Converting: " + dtrow[0].ToString() + " , " + count.ToString() + " of " + convimage.Rows.Count);
                Image img = Image.FromFile(@dtrow[1].ToString());
                ImageFormat thisFormat = img.RawFormat;
                string message = string.Format("Converting {0} ", @dtrow[1].ToString());
                byte[] arr;
                using (MemoryStream ms = new MemoryStream())
                {
                    img.Save(ms, thisFormat);
                    arr = ms.ToArray();
                }
                string convertedimg = "";
                convertedimg = Convert.ToBase64String(arr);
                Gears.RetriveData2("update dbo.ConvertedImage set ConvertedImage='" + convertedimg + "' where Keyfield = '" + dtrow[0].ToString() + "'", dtcon[0].ToString());
                ClearCurrentConsoleLine();

                Console.WriteLine("Converted: " + dtrow[0].ToString() + " , " + count.ToString() + " of " + convimage.Rows.Count);
            }
        }
        if (count == dtconnection.Rows.Count)
        {
            Console.WriteLine("Conversion is Finished. Press enter key to exit.");
        }
        Console.ReadLine();
    }

{{1}}

我尝试使用@ViewChild获取'搜索'但未定义 当我尝试使用@ViewChildren'搜索'时，我得到了

QueryList_dirty：false_emitter：EventEmitter_results：Array [1]更改：（...）dirty：（...）first：（...）last：（...）length：（...） proto ：对象

Answer 1

尝试添加此内容：

ngAfterViewChecked() {  // Called after child views changed
  if(this.showSearch && this.searchInput.first) {  // check is showSearch and ViewChildren has result
    this.searchInput.first.nativeElement.focus();  // set focus on native input element
  }
}