Why Does My Android App Throw \'The specified child already has a parent\' When Switching Layouts?

Child View Attachment Error in Android

When switching between layouts頻繁, an exception may arise: "The specified child already has a parent. You must call removeView() on the child's parent first."

Cause:

This error occurs when the view, in this case a TextView ("tv"), is already attached to a parent view group (LinearLayout "layout") when attempting to add it again to the new layout.

Context:

The provided code snippet demonstrates a layout-switching mechanism in Android. When the "ConsoleWindow()" method is executed initially, it sets the layout and adds "tv" to the "layout" without issue. However, when the layout is switched to a blank one and then back to the original layout, the error is thrown.

Solution:

The error message suggests the appropriate solution: removing the view from its current parent before adding it to the new parent. To accomplish this:

<code class="java">// TEXTVIEW
if(tv.getParent() != null) {
    ((ViewGroup)tv.getParent()).removeView(tv); // <- fix
}
layout.addView(tv);</code>

This check ensures that if "tv" is already attached to another parent view group, it is first removed before being added to the new layout, resolving the attachment issue.

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