ImageView 中不需要的填充或边距

Question

I am brand new to android to android development and just playing around with xmls for building layouts. I wrote the following code stuffs for printing a hello ubuntu and inserting an image in it. But the Image seems to have a unwanted upper and bottom padding or margin (not sure what it's called) which looks wierd. Please anyone help me removing it. Here is my code:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:background="@color/colorAccent"
    android:orientation="vertical"
    android:padding="10dp">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="8dp"
        android:layout_margin="8dp"
        android:text="Hello Ubuntu (16.06LTS)"
        android:background="@color/colorPrimary"/>

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="0dp"
        android:src="@mipmap/Ubuntu"
        android:layout_margin="0dp"/>

</LinearLayout>

Screenshot here(see the preiew on right side):

Answer 1

those extra padding is autogenerated since the android would try to get the original aspect ratio. please try below

scaletype = "fitCenter"
android:adjustViewBounds="true"
android:layout_width="match_parent"
android:layout_height="wrap_content"

Answer 2

You should use android:scaleType (see documentation ). This will allow you to tell the view how to react if the image does not have the exact size of the view.

Answer 3

You can try

android:adjustViewBounds="true" ,

it works for me.

   <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:background="@color/colorAccent"
    android:orientation="vertical"
    android:padding="10dp"
    >
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="8dp"
        android:layout_margin="8dp"
        android:text="Hello Ubuntu (16.06LTS)"
        android:background="@color/colorPrimary"/>
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:src="@drawable/asd"
        android:layout_margin="0dp"
        android:adjustViewBounds="true"

        />
</LinearLayout>

Answer 4

There is a margin above the imageview but it is not the part of imageview. It is actually because of margin applied to the textview above the imageview. You can do the following code.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:background="#00ffff"
android:orientation="vertical"
android:padding="10dp"
>
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginTop="8dp"
    android:text="Hello Ubuntu (16.06LTS)"
    android:background="#000000"/>

<ImageView
    android:layout_width="371dp"
    android:layout_height="match_parent"
    android:padding="0dp"
    android:background="#ff0000"
    android:layout_margin="0dp"
    />

EDIT - In your above code, you have applied Margin to all the sides of the view. ( android:layout_margin="8dp ") This gives the margin to the view from all the 4 sides including the bottom one, which appears as the imageview's top margin.

Hence, what you need to do is to apply margin to the view side by side by changing android:layout_margin="8dp" to

android:layout_marginLeft="8dp" android:layout_marginRight="8dp" android:layout_marginUpper="8dp"

EDIT 2 - Make sure you have 0 padding and 0 margin in the parent (root) container.