android is a strange phenomenon, when calling findviewbyid, display layout changed? ? ! !

            
Today when doing an android application, use a layout to achieve the results shown below: When two buttons on both sides, but when was the middle of the layout match_parent between left and right, that is between the full layout around, here is the layout file:
main.xml

  
android: layout_width = "match_parent" 
android: layout_height = "match_parent" 
android: orientation = "vertical"> 
layout = "@ layout / top_bar" /> 
android: id = "@ + id / realtabcontent" 
android: layout_width = "match_parent" 
android: layout_height = "0dip" 
android: layout_weight = "1" /> 

android: id = "@ + id / tabhost" 
android: layout_width = "match_parent" 
android: layout_height = "wrap_content"> 
 

 

top_bar.xml:

  
android: layout_width = "fill_parent" 
android: layout_height = "wrap_content" 
android: background = "@ drawable / topbar_bg"> 

android: id = "@ + id / topbar_left_btn" 
android: layout_width = "wrap_content" 
android: layout_height = "wrap_content" 
android: layout_alignParentLeft = "true" 
android: layout_centerVertical = "true" 
android: layout_marginLeft = "10dip" 
android: background = "@ color / transparent" 
android: onClick = "leftBtnClick" 
android: src = "@ drawable / add_friend" /> 

android: id = "@ + id / top_bar_title" 
android: layout_width = "wrap_content" 
android: layout_height = "wrap_content" 
android: layout_centerInParent = "true" 
android: gravity = "center" 
android: textColor = "@ color / white" 
android: textSize = "20sp" /> 

android: id = "@ + id / topbar_right_btn" 
android: layout_width = "wrap_content" 
android: layout_height = "wrap_content" 
android: layout_alignParentRight = "true" 
android: layout_centerVertical = "true" 
android: layout_marginRight = "10dip" 
android: background = "@ color / transparent" 
android: onClick = "rightBtnClick" 
android: src = "@ drawable / add_friend" /> 

android: id = "@ + id / radio_group" 
android: layout_width = "match_parent" 
android: layout_height = "wrap_content" 
android: layout_centerVertical = "true" 
android: layout_toLeftOf = "@ id / topbar_right_btn" 
android: layout_toRightOf = "@ id / topbar_left_btn" 
android: orientation = "horizontal" 
android: visibility = "visible"> 

android: id = "@ + id / auth_tab" 
android: layout_width = "wrap_content" 
android: layout_weight = "1" 
android: background = "@ drawable / add_btn_focus" 
android: button = "@ null" 
android: checked = "true" 
android: gravity = "center" /> 

android: id = "@ + id / original_tab" 
android: layout_width = "wrap_content" 
android: layout_weight = "1" 
android: background = "@ drawable / add_btn_focus" 
android: button = "@ null" 
android: gravity = "center" /> 
 

 

Set up between the two button:
android: layout_toLeftOf = "@ id / topbar_right_btn"
android: layout_toRightOf = "@ id / topbar_left_btn"
Meanwhile match_parent
This time I just do not call in the Activity:

 mAddFriendBtn = (ImageButton) findViewById (R.id.topbar_right_btn); 

Displayed correctly:

; If once the call:

 mAddFriendBtn = (ImageButton) findViewById (R.id.topbar_right_btn); 

On display:


I do not know in the end what is the reason when (models is os2.3.5, when the code sdk 4.0)

Finally, only through

 android: onClick event to listen for the 

Reply:
Did not see it, Bangding.
RelativeLayout replaced with LinearLayout you?
Reply:

 android: id = "@ + id / radio_group" 
android: layout_width = "match_parent" 

Changed

 android: id = "@ + id / radio_group" 
android: layout_width = "0dip" 
android: layout_weight = "1" 

Try
Reply:

cited a floor ameyume reply:

not see it, Bangding.
RelativeLayout replaced with LinearLayout you?

reference to the second floor ncepu307 reply:

 android: id = "@ + id / radio_group" 
android: layout_width = "match_parent" 

Changed

 android: id = "@ + id / radio_group" 
android: layout_width = "0dip" 
android: layout_weight = "1" 

Try

According to the first floor and second floor of the answers, you can now achieve that kind of effect, while:

 mAddFriendBtn = (ImageButton) findViewById (R.id.topbar_right_btn); 

Also not affect the layout.

Topbar.xml changed:

  
android: layout_width = "fill_parent" 
android: layout_height = "wrap_content" 
android: background = "@ drawable / topbar_bg" 
android: orientation = "horizontal"> 

android: id = "@ + id / topbar_left_btn" 
android: layout_width = "wrap_content" 
android: layout_height = "wrap_content" 
android: layout_gravity = "center_vertical" 
android: layout_marginLeft = "10dip" 
android: background = "@ color / transparent" /> 

android: id = "@ + id / top_bar_title" 
android: layout_width = "0dip" 
android: layout_height = "wrap_content" 
android: layout_gravity = "center" 
android: layout_weight = "1" 
android: gravity = "center" 
android: textColor = "@ color / white" 
android: textSize = "20sp" /> 

android: id = "@ + id / radio_group" 
android: layout_width = "0dip" 
android: layout_height = "wrap_content" 
android: layout_weight = "1" 
android: orientation = "horizontal" 
android: visibility = "gone"> 

android: id = "@ + id / auth_tab" 
android: layout_width = "wrap_content" 
android: layout_weight = "1" 
android: button = "@ null" 
android: checked = "true" 
android: gravity = "center" /> 

android: id = "@ + id / original_tab" 
android: layout_width = "wrap_content" 
android: layout_weight = "1" 
android: button = "@ null" 
android: gravity = "center" /> 
 

android: id = "@ + id / topbar_right_btn" 
android: layout_width = "wrap_content" 
android: layout_height = "wrap_content" 
android: layout_gravity = "center_vertical" 
android: layout_marginRight = "10dip" 
android: background = "@ color / transparent" /> 
 

But why is there such a problem, or did not get to know the reason
Reply:
RadioGroup above attributes

 android: visibility = "gone" 

TextView should be placed where a misplaced
Reply:
If there is a android: visibility = "gone" certainly changes the layout of your location, the best android: visibility = "invisible"
Reply:

references, 5th Floor lieri111 reply:

if there is a android: visibility = "gone" certainly position your layout changes, the best android: visibility = " invisible "

Ah, I just let textview or below RadioGroup centered
As with the first method, why cause strange to change the layout of this are not clear what is the reason
Reply:
Layout of such a rule, you should use LinearLayout
Reply:
Your original radio_group of android_width = "match_parent", is it the right to occupy all the space, so invisible to the right of the Add button.
Reply:

reference to the 8th floor ncepu307 reply:

your original radio_group of android_width = "match_parent", is it the right to occupy all the space, so that the right side of the invisible the Add button.

But I set

 android: layout_toLeftOf = "@ id / topbar_right_btn" 

Also, if there is no call

 mAddFriendBtn = (ImageButton) findViewById (R.id.topbar_right_btn); 

Displayed normal, if it gets through this button once instance, will occupy space on the right
Reply:

reference to the 9th floor swust_chenpeng reply:

Quote: references to the 8th floor ncepu307 reply:

Your original radio_group of android_width = "match_parent", is it the right to occupy all the space, so invisible to the right of the Add button.

But I set

 android: layout_toLeftOf = "@ id / topbar_right_btn" 

Also, if there is no call

 mAddFriendBtn = (ImageButton) findViewById (R.id.topbar_right_btn); 

Displayed normal, if it gets through this button once instance, will occupy space on the right

This strange performance is concerned with match_parent and RelativeLayout.