Apache Royale中j:Button无enabled属性，如何用AS3代码控制启用/禁用？

Got it, let's walk through how to toggle your j:Button's enabled state using AS3. Since you’ve already added the j:Disabled bead in your MXML, the key is to access that bead in your ActionScript code and adjust its property.

Step-by-Step Implementation #

1. Reference your button instance
   If your button has the ID bp_next (like in your MXML snippet), you can grab it directly in your AS3 code (assuming it’s in the same scope):

   var nextButton:Button = bp_next as Button;
   

2. Retrieve the Disabled bead
   Use the getBeadByType() method to fetch the Disabled bead attached to the button:

   var disabledBead:Disabled = nextButton.getBeadByType(Disabled) as Disabled;
   

3. Toggle the enabled state
   Now you can control whether the button is enabled or disabled by setting the disabled property of the bead:

   • To enable the button:

     if (disabledBead) {
         disabledBead.disabled = false;
     }
     

   • To disable the button:

     if (disabledBead) {
         disabledBead.disabled = true;
     }
     

Full Example Code #

Here’s a complete snippet you can use to wrap this logic into a reusable function:

// Don't forget to import the required classes
import org.apache.flex.html.Button;
import org.apache.flex.html.beads.Disabled;

private function setButtonEnabled(button:Button, isEnabled:Boolean):void {
    var disabledBead:Disabled = button.getBeadByType(Disabled) as Disabled;
    if (disabledBead) {
        disabledBead.disabled = !isEnabled;
    }
}

// Usage: Enable the "Next" button
setButtonEnabled(bp_next, true);

// Usage: Disable the "Next" button
setButtonEnabled(bp_next, false);

A quick reminder: Make sure you’ve imported the correct Button and Disabled classes to avoid compilation errors. Since you already added the j:Disabled bead in MXML, the bead will exist on the button instance once it’s initialized, so the getBeadByType() call should return a valid reference.

内容的提问来源于stack exchange，提问作者Fred