Xamarin：如何更改代码中添加的按钮的颜色？

Question

My Xamarin app creates buttons in code. I can change the color of a button I click, as the button is referenced in its Clicked handler's sender argument, but I want to change the color of buttons that I didn't click. The problem is, how do I find the buttons I want to change?

I thought about using FindByName, but Name doesn't appear to be an attribute.

One way I can think of: loop through all of the buttons until I find the one with the StyleId of the desired button. Is there an easier way than that?

Answer 1

when you create a button in code you need to keep a reference to it, like you would with any C# object you want to reference later

Button MyButton = new Button { ... };
MyButton.BackgroundColor = Color.Purple;

if you need to access it from multiple places in your code, you should declare it as a class level variable to that it has scope throughout your class

Answer 2

If you want to find the button created in code behind without XAML, like @Jason said, use the variable name of the Button you created or set it directly.

 Button button = new Button { ClassId = "button1", BackgroundColor = Color.Red };

If you want to access a view with FindByName , you need to create the button with x:Name in XAML.

There is an XAML example:

<Button x:Name="button1" ></Button>

And in your code behind you could do something like:

 button1.BackgroundColor = Color.Red;

If you need to find a view in xaml for some reason, do this:

var button = this.FindByName<Button>("button1");
button.BackgroundColor = Color.Red;