问题
I need to draw a horizontal line below a text field such that the width of the line equals the text width (not the width of the full screen).
In my app I have a textview below a view(Horizontal line). The width of the line view should be equal to the width of the textview. I tried android:layout_width="wrap_content" and "match_parent", which does not solve the problem.
This is xml coding sample:
......
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="28dp"
android:text="PopUpWindow"
android:textAppearance="?android:attr/textAppearanceLarge" />
<View
android:id="@+id/separator"
android:layout_width="wrap_content"
android:layout_height="0.3dp"
android:layout_below="@+id/textView1"
android:background="#ffffff" />
......
image of the screen is:
please help me.
回答1:
If you use a RelativeLayout you can use the align-attributes:
<View
android:id="@+id/separator"
android:layout_width="0dp"
android:layout_height="0.3dp"
android:layout_below="@+id/textView1"
android:layout_alignLeft="@+id/textView1"
android:layout_alignRight="@+id/textView1"
android:background="#ffffff" />
回答2:
If you're using a Layout other than a RelativeLayout, you can match the widths of your widgets programmatically, such as in this example:
layout.xml:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TextView
android:id="@+id/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Here's some text"
/>
<TextView
android:id="@+id/text2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Some more text"
/>
</LinearLayout>
Notice that both text fields are both set to wrap_content.
Main.java:
TextView tv1 = (TextView) findViewById(R.id.text1);
TextView tv2 = (TextView) findViewById(R.id.text2);
if(tv1.getWidth() < tv2.getWidth())
tv1.setWidth(tv2.getWidth());
else
tv2.setWidth(tv1.getWidth());
If you have multiple widgets that you want to have a uniform width, just repeat the above code for the new element. For example, let's say there was a button I wanted to adjust the width to, to match the other elements:
if(tv2.getWidth() < button)
tv2.setWidth(button.getWidth());
else
button.setWidth(tv2.getWidth());
回答3:
Use RelativeLayout and use these two attribute in horizontal line view
android:layout_alignLeft="@+id/textView1" android:layout_alignRight="@+id/textView1"
<RelativeLayout
android:id="@+id/relativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1.23" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="67dp"
android:text="this is TextView" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="10dp"
android:layout_alignLeft="@+id/textView1"
android:layout_alignRight="@+id/textView1"
android:layout_below="@+id/textView1"
android:background="#FF0000"
android:text="" />
</RelativeLayout>
回答4:
What Jave said is correct - and the easiest, but what if you're not using a RelativeLayout to contain the View's ?
If you're customizing your UI within onCreate() then you'll find that obtaining the width from another widget will give you an incorrect result ! That's because the UI hasn't been set up yet.
But you can still set up your UI within onCreate... simply run code that executes after the UI is set up. This is achieved through use of the View.post() command.
The XML :
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:gravity="center">
<Button
android:id="@+id/button_one"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:text="short string" />
<Button
android:id="@+id/button_two"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="this is a longer string" />
</LinearLayout>
</RelativeLayout>
Java code:
private Button mButtonOne;
private Button mButtonTwo;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// inflate UI
setContentView(R.layout.activity_example);
// get references to UI elements
mButtonOne = (Button)findViewById(R.id.button_one);
mButtonTwo = (Button)findViewById(R.id.button_two);
// Make buttons the same size (i.e. Button1.width = Button2.width)
if ((mButtonOne != null) && (mButtonTwo != null))
{
mButtonOne.post(new Runnable()
{
@Override
public void run()
{
mButtonOne.setWidth(mButtonTwo.getWidth());
}
});
}
}
The result is that the Width of button_one will match the Width of button_two. This is a nicer look when the amount of text varies heavily between the two View's.
回答5:
If you don't want to use RelativeLayout then you can set parent's width to wrap content and parent's width will become equal to biggest child. Then you can set the width of the small child to match_parent and it'll match the width of required view.
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical|left"
android:orientation="vertical"
android:layout_gravity="center_vertical"
android:padding="5dp">
<TextView
android:id="@+id/navHeaderName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/profile_progress_bar"
android:text="This is a large text"
android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
<ProgressBar
android:id="@id/profile_progress_bar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:max="100"
android:progress="45" />
</LinearLayout>
回答6:
It depends on your use case. If you plan to modify things in the layout dynamically and have them also sized the same as the TextView, you may want to wrap them in a parent view together. If it's a one-time thing, use RelativeLayout as suggested by the other answer here.
<LinearLayout android:orientation="vertical" ... > <!-- layout parameters as appropriate-->
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="28dp"
android:text="PopUpWindow"
android:textAppearance="?android:attr/textAppearanceLarge" />
<View
android:id="@+id/separator"
android:layout_width="match_parent"
android:layout_height="0.3dp"
android:layout_below="@+id/textView1"
android:background="#ffffff" />
</LinearLayout>
回答7:
use following width attribute.
<TextView
android:id="@+id/textView1"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="28dp"
android:text="PopUpWindow"
android:textAppearance="?android:attr/textAppearanceLarge" />
<View
android:id="@+id/separator"
android:layout_width="150dp"
android:layout_height="0.3dp"
android:layout_below="@+id/textView1"
android:background="#ffffff" />
来源：https://stackoverflow.com/questions/9977721/how-to-set-width-which-is-equal-to-another-widget-on-android