CODEWITHSUNDEEP
android
quux
quux

Reputation: 918

How to get parent id on Android?

I've tried to get parent id of RadioButton (id of RadioGroup) by

RadioGroup rg = (RadioGroup) arg0.getParent();

but it failed. Following construction

RadioGroup rg = (RadioGroup) findViewById(R.id.radiogr);

works well. How can I get parent id at runtime?

fails with these logs:

12-26 17:11:05.205: E/AndroidRuntime(912): FATAL EXCEPTION: main
12-26 17:11:05.205: E/AndroidRuntime(912): java.lang.ClassCastException: android.widget.LinearLayout
12-26 17:11:05.205: E/AndroidRuntime(912):  at com.letmedraw.shopcart.ShopCartActivity.onCheckedChanged(ShopCartActivity.java:96)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.RadioGroup.setCheckedId(RadioGroup.java:172)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.RadioGroup.access$600(RadioGroup.java:52)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.RadioGroup$CheckedStateTracker.onCheckedChanged(RadioGroup.java:342)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.CompoundButton.setChecked(CompoundButton.java:127)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.CompoundButton.toggle(CompoundButton.java:86)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.RadioButton.toggle(RadioButton.java:69)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.widget.CompoundButton.performClick(CompoundButton.java:98)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.view.View$PerformClick.run(View.java:8816)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.os.Handler.handleCallback(Handler.java:587)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.os.Handler.dispatchMessage(Handler.java:92)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.os.Looper.loop(Looper.java:123)
12-26 17:11:05.205: E/AndroidRuntime(912):  at android.app.ActivityThread.main(ActivityThread.java:4627)
12-26 17:11:05.205: E/AndroidRuntime(912):  at java.lang.reflect.Method.invokeNative(Native Method)
12-26 17:11:05.205: E/AndroidRuntime(912):  at java.lang.reflect.Method.invoke(Method.java:521)
12-26 17:11:05.205: E/AndroidRuntime(912):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
12-26 17:11:05.205: E/AndroidRuntime(912):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
12-26 17:11:05.205: E/AndroidRuntime(912):  at dalvik.system.NativeStart.main(Native Method)

Upvotes: 3

Views: 12791

Answers (4)

Asad Ali Choudhry
Asad Ali Choudhry

Reputation: 5261

Just to more clarify the accepted answer, You can get parent Id (in integer form) of view any view, Like this

int parentId = ((View) arg0.getParent()).getId();

And now you can compare id with R.id to take your action. Because ids of all views are saved in R file in Android in integer format.

if (parentId == R.id.your_id) { //
     // Do whatever you want
}

Upvotes: 0

Tomislav Markovski
Tomislav Markovski

Reputation: 12346

All views (controls) in android are of type View, so you can use getId() to find the id.

int parentId = ((View) arg0.getParent()).getId();

Upvotes: 14

kosa
kosa

Reputation: 66637

It seems arg0 parent is LinearLayout, not Radio group and you are trying it to cast it as RadioGroup that is why it is throwing exception.

Upvotes: 0

Dmitry Zaytsev
Dmitry Zaytsev

Reputation: 23952

Because getParent() is not RadioGroup value, and not an id either. getParent() returns ViewParent type, not a View.

ViewParent is interface and View is a class.

Upvotes: 1

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