问题
Currently, I have the following bottom log in button.
When button is not being pressed
When button is being pressed
The XML looks like this
<LinearLayout
android:background="?attr/welcomeBottomNavBarBackground"
android:orientation="horizontal"
android:id="@+id/sign_in_bottom_nav_bar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
<Button
style="?android:attr/buttonBarButtonStyle"
android:id="@+id/sign_in_button"
android:layout_width="0dp"
android:width="0dp"
android:layout_weight="1.0"
android:layout_height="48dp"
android:gravity="center"
android:layout_gravity="center"
android:enabled="true"
android:textAllCaps="true"
android:text="@string/log_in" />
</LinearLayout>
I would like to remove the padding (Or should I call it margin? Please refer to my bottom most p/s section) around button when it is being pressed.
I look at How to remove padding around buttons in Android?
I had tried
<Button
...
...
android:minHeight="0dp"
android:minWidth="0dp" />
It doesn't work and has no effect.
I further try
<Button
...
...
android:background="@null"
android:minHeight="0dp"
android:minWidth="0dp" />
No more padding when pressed. However, the material designed pressed visual effect will gone too.
May I know what is the best way to remove button padding during pressed, yet retain the material designed pressed visual effect?
P/S
I don't really know whether I should call it padding or margin. What I wish to achieve is that, when we press on the bottom region, press visual effect change should be covered entire 100% bottom bar region (@+id/sign_in_bottom_nav_bar), instead of current 95% bottom bar region.
回答1:
A standard button is not supposed to be used at full width which is why you experience this.
Background
If you have a look at the Material Design - Button Style you will see that a button has a 48dp height click area, but will be displayed as 36dp of height for...some reason.
This is the background outline you see, which will not cover the whole area of the button itself.
It has rounded corners and some padding and is supposed to be clickable by itself, wrap its content, and not span the whole width at the bottom of your screen.
Solution
As mentioned above, what you want is a different background. Not a standard button, but a background for a selectable item with this nice ripple effect.
For this use case there is the ?selectableItemBackground theme attribute which you can use for your backgrounds (especially in lists).
It will add a platform standard ripple (or some color state list on < 21) and will use your current theme colors.
For your usecase you might just use the following:
<Button
android:id="@+id/sign_in_button"
style="?android:attr/buttonBarButtonStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Login"
android:background="?attr/selectableItemBackground" />
<!-- /\ that's all -->
There is also no need to add layout weights if your view is the only one and spans the whole screen
If you have some different idea on what your background should look like you have to create a custom drawable yourself, and manage color and state there.
回答2:
In styles.xml
<style name="MyButtonStyle" parent="Base.Widget.AppCompat.Button">
<item name="android:background">@drawable/selector</item>
<item name="android:textColor">@android:color/black</item>
</style>
In values/drawable:
my_drawable.xml
<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="rectangle" xmlns:android="http://schemas.android.com/apk/res/android">
<corners android:radius="2dp" />
<!-- specify your desired color here -->
<solid android:color="#9e9b99" />
</shape>
selector.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_focused="true" android:drawable="@drawable/my_drawable"/>
<item android:state_pressed="true" android:drawable="@drawable/my_drawable"/>
<item android:drawable="@android:color/transparent"/>
</selector>
In values/drawable-v21:
my_drawable.xml
<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="rectangle"
android:tint="?attr/colorButtonNormal"
xmlns:android="http://schemas.android.com/apk/res/android">
<corners android:radius="2dp" />
<solid android:color="@android:color/white" />
</shape>
selector.xml
<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
android:color="?attr/colorControlHighlight">
<item android:id="@android:id/mask"
android:drawable="@drawable/my_drawable" />
</ripple>
In layout:
<Button
android:id="@+id/button"
style="@style/MyButtonStyle"
android:layout_width="match_parent"
android:layout_height="100dp"
android:text="Test"/>
Result on API 19:
Result on API 21:
Source code
回答3:
I think the best solution to solve that is create your own Ripple Effect. The padding when you press the button is respecting the default Ripple Effect of the component.
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
android:color="?attr/colorControlHighlight">
<item android:drawable="?attr/colorPrimary"/>
</ripple>
Or you can try change the style of your button to style="?android:textAppearanceSmall"
Remember: This effect is only shown on Android Lollipop (API 21) or higher.
回答4:
I have been through what you are going through. Long story short, you just cannot do it cleanly with a <Button> tag alone, while ensuring backwards compatibility.
The simplest and the most widely practiced method is to use a <RelativeLayout> underlay, around a <Button>.
Button Code:
<RelativeLayout
android:id="@+id/myButtonUnderlay"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPrimary"
android:visibility="visible">
<Button
android:id="@+id/myButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/selectableItemBackgroundBorderless"
android:text="I am as cute as a Button"/>
</RelativeLayout>
Wherever you need to use a button, you use this complete code.
Here is the breakdown:
- OnClick events will be hooked to
myButton. - Control dimensions of your button, by changing attributes of
myButtonUnderlay. - In
myButton,android:background="?attr/selectableItemBackgroundBorderless". This will make it a transparent button with just the text, and backwards compatible ripples. - In
myButtonUnderlay, you will do all the other background applications, like setting the color of the button, margins, paddings, borders, gradients, and shadows etc. - If manipulation of the button's visibility (programmatic or not) is wish, you do it on
myButtonUnderlay.
Note: To ensure backwards compatibility, make sure that you use
android:background="?attr/selectableItemBackgroundBorderless", and NOT
android:background="?android:attr/selectableItemBackgroundBorderless"
回答5:
As @David Medenjak answer you can read the Google Material design Button-style to its developer site. Use button style as @David Medenjak explained in his answer. You can also do by the following way also It is not a padding or margin but it is actually background effect of button. If you want to remove that then you can do as following.
Option 1:
Step 1: Put the below code in styles.xml
<style name="myColoredButton">
<item name="android:textColor">#FF3E96</item>
<item name="android:padding">0dp</item>
<item name="android:minWidth">88dp</item>
<item name="android:minHeight">36dp</item>
<item name="android:elevation">1dp</item>
<item name="android:translationZ">1dp</item>
<item name="android:background">#FF0000</item>
</style>
Step 2:Create a new XML file under drawables folder and add the following code: I named my XML file as button_prime.xml
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
android:color="@color/colorPrimary">
<item>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<corners android:radius="1dp" />
<solid android:color="#8B8386" />
</shape>
</item>
</ripple>
Step 3: Use the style and drawable in your Button as follows.
<Button
style="@style/myColoredButton"
android:layout_width="250dp"
android:layout_height="50dp"
android:text="Cancel"
android:gravity="center"
android:background="@drawable/button_prime"
android:colorButtonNormal="#3578A9" />
Option 2:
With the Support Library v7, all the styles are actually already defined and ready to use, for the standard buttons, all of these styles are available.So you can set your button style like this
<Button
style="@style/Widget.AppCompat.Button.Borderless"
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="BUTTON"
android:gravity="center"
android:minHeight="0dp"
android:minWidth="0dp"
android:background="@color/colorAccent"/>
For more detail of Button style please check this answer
I think you will check this answer also. I hope you will get your solution.
回答6:
The padding and margin may be a result of the original resources used in the button.
So you could try to change the resources used, using a selector:
<selector
xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" android:drawable="@drawable/btn_action_hover" />
<item android:state_selected="true" android:drawable="@drawable/btn_action_hover" />
<item android:state_focused="true" android:drawable="@drawable/btn_action_hover" />
<item android:drawable="@drawable/btn_action_normal" />
</selector>
That would change the default images/shapes for your buttons, so you could try using drawables and set every item to a drawable. The drawable being either a bitmap, or a .xml file(style file) defining the look of the button in its current state. I assume there still are some native styles included even though you have set the button-style yourself. This may be because you aren't using a custom theme. So the issue may also be solved by defing
theme="@style/myNewTheme"
where myNewTheme is your theme, and it should have any parents(parent="" should not be defined).
Take any given theme(designed by Google/Android, for an instance Theme.AppCompat.[name]), it does also come with a buttonStyle. This is a part of Theme.Holo.Light:
<!-- Button styles -->
<item name="buttonStyle">@style/Widget.Holo.Light.Button</item>
<item name="buttonStyleSmall">@style/Widget.Holo.Light.Button.Small</item>
<item name="buttonStyleInset">@style/Widget.Holo.Light.Button.Inset</item>
<item name="buttonStyleToggle">@style/Widget.Holo.Light.Button.Toggle</item>
<item name="switchStyle">@style/Widget.Holo.Light.CompoundButton.Switch</item>
<item name="mediaRouteButtonStyle">@style/Widget.Holo.Light.MediaRouteButton</item>
<item name="selectableItemBackground">@drawable/item_background_holo_light</item>
<item name="selectableItemBackgroundBorderless">?attr/selectableItemBackground</item>
<item name="borderlessButtonStyle">@style/Widget.Holo.Light.Button.Borderless</item>
<item name="homeAsUpIndicator">@drawable/ic_ab_back_holo_light</item>
As you see, this theme defines how your buttons will look/work in basic features. You can override parts of it, but you haven't overridden the important parts(being buttonStyle and similar). So if you create a new theme yourself and style it to your liking and set the theme(using theme="themename") and that theme does not inherit any theme, you should be able to style your buttons to your liking without having to worry about the default styles in the theme
Basically:
calling padding/margin="0dp" will not help. The default drawable defined by the theme has this in the button drawable, meaning you cannot change it. So you have to either change the button style, or change the theme completely. Make sure that theme does not have any parents, because many themes define the button style. You do not want the button style defined by the theme.
回答7:
I'd suggest you taking a look at this just in case before all.
Then, if not working i'd suggest you to create your own style (like azizbekian suggest)using android xml drawables, and drawable states to differentiate pressed/notpressed.
I think using your own style may be the best answer as it will further give you more control on how your app is displaying, but using android default themes and styles also allows the user to have custom styles which is a good idea. However, you cannot test every custom style so you cannot check that your app will display correctly on ALL custom styles, and therefore may encounter problems with some.
回答8:
Set the Button background as android:background="?selectableItemBackground"
<LinearLayout
android:background="?attr/welcomeBottomNavBarBackground"
android:orientation="horizontal"
android:id="@+id/sign_in_bottom_nav_bar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
<Button
style="?android:attr/buttonBarButtonStyle"
android:background="?selectableItemBackground"
android:id="@+id/sign_in_button"
android:layout_width="0dp"
android:width="0dp"
android:layout_weight="1.0"
android:layout_height="48dp"
android:gravity="center"
android:layout_gravity="center"
android:enabled="true"
android:textAllCaps="true"
android:text="@string/log_in" />
</LinearLayout>
回答9:
After trying lots of solution, Finally I came to a conclusion that with tag alone we can't achieve this. to remove this unwanted space around button my solution is as below:
<RelativeLayout
android:id="@+id/myButtonUnderlay"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:visibility="visible">
<Button
android:id="@+id/save_button"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="-5dp"
android:layout_marginBottom="-5dp"
android:layout_above="@+id/content_scrollview"
android:layout_gravity="bottom"
android:background="@drawable/ripple_theme"
android:enabled="true"
android:text="SetUp Store"
android:textColor="#fff"
android:textSize="18sp"
android:visibility="gone"
tools:visibility="visible"
style="@style/MediumFontTextView" />
</RelativeLayout>
回答10:
As simple, use the inset property like:
android:insetTop="0dp"
android:insetBottom="0dp"
android:insetRight="0dp"
android:insetLeft="0dp"
回答11:
The best solution these days is just to use MaterialButton in place of Button.
Note: MaterialButton is visually different from Button and AppCompatButton. One of the main differences is that AppCompatButton has a 4dp inset on the left and right sides, whereas MaterialButton does not. To add an inset to match AppCompatButton, set android:insetLeft and android:insetRight on the button to 4dp, or change the spacing on the button’s parent layout.
When replacing buttons in your app with MaterialButton, you should inspect these changes for sizing and spacing differences.
Source: https://material.io/develop/android/components/material-button/
回答12:
1.add a drawable resource file named maybe button_background.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true">
<shape>
<solid android:color="#ff0000"/>
<stroke android:width="5dp" android:color="#00ff00"/>
</shape>
</item>
<item>
<shape>
<solid android:color="#00ff00"/>
</shape>
</item>
</selector>
2.Use the button_background.xml as the button background, done!
github
blog
回答13:
I don't really know whether I should call it padding or margin.
The button is enacting surface elevation for providing visual feedback in response to touch. It is one of two feedbacks used for surface reaction; the first one being the ripple effect. For example, a raised button has resting state elevation of 2dp and pressed state elevation of 8dp (See raised button under Shadows). The button meets the finger as it touches the surface.
May I know what is the best way to remove button padding during pressed, yet retain the material designed pressed visual effect?
Having answered the first part, I do not believe you are having all of the material design if you wish to remove the surface elevation effect.
Anyways, here is how to remove surface elevation visual feedback:
Add animator file button_raise.xml to animator directory under res directory having the following code:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_enabled="true"
android:state_pressed="true">
<objectAnimator
android:duration="@android:integer/config_shortAnimTime"
android:propertyName="translationZ"
android:valueTo="0dp"
android:valueType="floatType" />
</item>
</selector>
Refer newly created animator in the button using stateListAnimator property:
<Button
...
android:stateListAnimator="@animator/button_raise"
... />
Hope this helps.
来源：https://stackoverflow.com/questions/43192378/how-to-properly-remove-padding-or-margin-around-buttons-in-android