Android How do I correctly get the value from a Sw

问题:

I'm creating a Android application which uses a Switch.
I'm trying to listen for changes and get the value when changed.
I have two questions when using switches:

1. What action listener do I use?
2. How do I get the the switch value?

回答1:

Switch s = (Switch) findViewById(R.id.SwitchID);

if (s != null) {
    s.setOnCheckedChangeListener(this);
}

/* ... */

public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    Toast.makeText(this, "The Switch is " + (isChecked ? "on" : "off"),
                   Toast.LENGTH_SHORT).show();
    if(isChecked) {
        //do stuff when Switch is ON
    } else {
        //do stuff when Switch if OFF
    }
}

Hint: isChecked is the new switch value [true or false] not the old one.

回答2:

Since it extends from CompoundButton (docs), you can use setOnCheckedChangeListener() to listen for changes; use isChecked() to get the current state of the button.

回答3:

Switch switch = (Switch) findViewById(R.id.Switch2);

switch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if (isChecked) {
                        ...switch on..
                    } else {
                       ...switch off..
                    }
                }
            });

i hope this will solve your problem