这是新表格的顶部:
namespace test
{
public partial class Youtube_Uploader : Form
{
public class ComboboxItem
{
public string Text { get; set; }
public object Value { get; set; }
public override string ToString()
{
return Text;
}
}
YouTubeService service;
string devKey = "";
string apiKey = "";";
string userName = "";
string Password = "";
string feedUrl = "";
string FileNameToUpload = "";
string[] stringProgressReport = new string[5];
long totalBytes = 0;
DateTime dt;
Upload upload;
public Youtube_Uploader()
{
InitializeComponent();
service = AuthenticateOauth(apiKey);
var videoCatagories = service.VideoCategories.List("snippet");
videoCatagories.RegionCode = "IL";
var result = videoCatagories.Execute();
for (int i = 0; i < result.Items.Count; i++)
{
ComboboxItem item = new ComboboxItem();
item.Text = result.Items[i].Snippet.Title;
item.Value = result.Items[i].Id;
upload.comboBox1.Items.Add(item);
}
upload.comboBox1.SelectedIndex = 0;
MakeRequest();
}
例如,从上传上传变量上传 上传是一个新表单,通过变量上传我可以访问上传设计器中的控件。
“上传”表单中没有代码,只有我将其设置为公开的控件。
我的问题是为什么我看到上传绿线表示它未分配并且将为空? 你可以在构造函数中看到我做的例如:
upload.comboBox1.Items.Add(item);
我没有收到错误。也不例外。 我只是想知道我收到这个警告是不是一件坏事? 我所做的上传var就是访问上传表单的控件。
答案 0 :(得分:1)
以下是您可以做的事情,可以做一个简单的例子:
void Main()
{
Foo f1 = new Foo("good",6);
Foo f2;
string temp_string;
// You can do this
temp_string = f1.S;
// Bot not this
// temp_string = f2.S; --> Use of unassigned local variable 'f2'
// You can also do this:
int temp_int = Foo.I;
// But not
// temp_int = f1.I;
// You can do
bool b = TestFoo(f1);
// But not
// b = TestFoo(f2); --> Use of unassigned local variable 'f2'
}
public class Foo {
// static class property, can be accessed with "Foo.I"
public static int I {get; set;}
// instance property, can be accessed with "f1.S"
public string S { get; set; }
public Foo(string s, int i = 0) {
S = s;
I = i;
}
}
public bool TestFoo(Foo foo) {
return foo != null;
}