Dynamic Variable Name Use in C# for WinForms
Not sure what is the best way to word this, but I am wondering if a dynamic variable name access can be done in C# (3.5).
Here is the code I am currently looking to "smarten up" or make more elegant with a loop.
private void frmFilter_Load(object sender, EventArgs e)
{
chkCategory1.Text = categories[0];
chkCategory2.Text = categories[1];
chkCategory3.Text = categories[2];
chkCategory4.Text = categories[3];
chkCategory5.Text = categories[4];
chkCategory6.Text = categories[5];
chkCategory7.Text = categories[6];
chkCategory8.Text = categories[7];
chkCategory9.Text = categories[8];
chkCategory10.Text = ca开发者_如何学编程tegories[9];
chkCategory11.Text = categories[10];
chkCategory12.Text = categories[11];
}
Is there a way to do something like ("chkCategory" + i.ToString()).Text?
Yes, you can use
Control c = this.Controls.Find("chkCategory" + i.ToString(), true).Single();
(c as textBox).Text = ...;
Add some errorchecking and wrap it in a nice (extension) method.
Edit: It returns Control[]
so either a [0]
or a .Single()
are needed at the end. Added.
for(...)
{
CheckBox c = this.Controls["chkCategory" + i.ToString()] as CheckBox ;
c.Text = categories[i];
}
You can do that with reflection. But don't.
It's more proper to instantiate a list of contols, add them programmatically to your form, and index that.
Sometimes it can help to put your controls into an array or collection as such:
Checkbox[] chkCataegories = new Checkbox[] { chkCategory1, chkCategory2 ... };
for(int i = 0; i < chkCategories.Length; i++)
chkCategories[i].Text = categories[i];
As another approach, you can dynamically create your checkboxes at runtime instead of design time:
for(int i = 0; i < categories.Length; i++)
{
Checkbox chkCategory = new chkCategory { Text = categories[i] };
someContainer.Controls.Add(chkCategory);
}
At least with dynamically created controls, you don't need to modify your GUI or your form code whenever you add new categories.
You don't need dynamic for that. Put chkCategory1 - 12 in an array, and loop through it with a for loop. I would suggest you keep it around in a field and initialize it at form construction time, because chkCategory seems to be related. But if you want a simple example of how to do it in that simple method, then it would be something like this:
private void frmFilter_Load(object sender, EventArgs e)
{
var chkCategories = new [] { chkCategory1, chkCategory2, chkCategory3, .......... };
for(int i = 0 ; i < chkCategories.Length ; i++ )
chkCategoies[i].Text = categories[i];
}
You know more about the application, so you could perhaps avoid writing out all the control names - for instance, if they are placed on a common parent control, then you could find them by going through it's children.
No, but you could do something like this (untested, beware of syntax errors):
private readonly CheckBox[] allMyCheckboxes = new CheckBox[] { chkCategory1, chkCategory2, ... }
Then you just need to do
for (i = 0; i < 12; i++) allMyCheckboxes[i].Text = categories[i];
The "this.Controls["chkCategory" + i.ToString()]" and "this.Controls.Find("chkCategory" + i.ToString(), true)" both do not work... the former informs you that the contents of the [] are not an int and the latter that ControlCollection does not contain a definition for Find.
Use "Control myControl1 = FindControl("TextBox2");" instead.
I needed this form as I was looping through another array, extracting values and using them to populate form fields. Much easier to look for label1, label2, label3, etc.
精彩评论