Asked  6 Months ago    Answers:  5   Viewed   43 times

I want to know: What is android:weightSum and layout weight, and how do they work?

 Answers

54

Per documentation, android:weightSum defines the maximum weight sum, and is calculated as the sum of the layout_weight of all the children if not specified explicitly.

Let's consider an example with a LinearLayout with horizontal orientation and 3 ImageViews inside it. Now we want these ImageViews always to take equal space. To acheive this, you can set the layout_weight of each ImageView to 1 and the weightSum will be calculated to be equal to 3 as shown in the comment.

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    <!-- android:weightSum="3" -->
    android:orientation="horizontal"
    android:layout_gravity="center">

   <ImageView
       android:layout_height="wrap_content"       
       android:layout_weight="1"
       android:layout_width="0dp"/>
  .....

weightSum is useful for having the layout rendered correctly for any device, which will not happen if you set width and height directly.

Tuesday, June 1, 2021
 
WooDzu
answered 6 Months ago
65

A continue statement without a label will re-execute from the condition the innermost while or do loop, and from the update expression of the innermost for loop. It is often used to early-terminate a loop's processing and thereby avoid deeply-nested if statements. In the following example continue will get the next line, without processing the following statement in the loop.

while (getNext(line)) {
  if (line.isEmpty() || line.isComment())
    continue;
  // More code here
}

With a label, continue will re-execute from the loop with the corresponding label, rather than the innermost loop. This can be used to escape deeply-nested loops, or simply for clarity.

Sometimes continue is also used as a placeholder in order to make an empty loop body more clear.

for (count = 0; foo.moreData(); count++)
  continue;

The same statement without a label also exists in C and C++. The equivalent in Perl is next.

This type of control flow is not recommended, but if you so choose you can also use continue to simulate a limited form of goto. In the following example the continue will re-execute the empty for (;;) loop.

aLoopName: for (;;) {
  // ...
  while (someCondition)
  // ...
    if (otherCondition)
      continue aLoopName;
Tuesday, June 1, 2021
 
mozlima
answered 6 Months ago
78

Use Like this:

Remove Linear layout. use relative layout and inside that place your two list view like this.

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/scrollojt"
android:fillViewport="true" >

   <RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >

<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#f00" >
 </ListView>

 <ListView
android:id="@+id/listView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/listView1"
android:background="#0f0" >
</ListView>
    </RelativeLayout>
  </ScrollView>

add Utility.java

public class Utility {

    public static void setListViewHeightBasedOnChildren(ListView listView) {
        ListAdapter listAdapter = listView.getAdapter();
        if (listAdapter == null) {
            // pre-condition
            return;
        }

        int totalHeight = 0;
        int desiredWidth = MeasureSpec.makeMeasureSpec(listView.getWidth(), MeasureSpec.AT_MOST);
        for (int i = 0; i < listAdapter.getCount(); i++) {
            View listItem = listAdapter.getView(i, null, listView);
            listItem.measure(desiredWidth, MeasureSpec.UNSPECIFIED);
            totalHeight += listItem.getMeasuredHeight();
        }

        ViewGroup.LayoutParams params = listView.getLayoutParams();
        params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
        listView.setLayoutParams(params);
        listView.requestLayout();
    }
}

In your Activity:

 lv1.setAdapter(adapter);
 lv2.setAdapter(adapter);

Utility.setListViewHeightBasedOnChildren(lv1);
Utility.setListViewHeightBasedOnChildren(lv2);
Wednesday, June 2, 2021
 
Fernando
answered 6 Months ago
96

SharedUserId is used to share the data,processes etc between two or more applications. It is defined in AndroidManifest.xml like,

<manifest
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:sharedUserId="android.uid.shared"
    android:sharedUserLabel="@string/sharedUserLabel"
    ...>

and define the shared parameter in Android.mk for that app, like

LOCAL_CERTIFICATE := shared

Hope its helpful to you.

Wednesday, June 2, 2021
 
Jimenemex
answered 6 Months ago
40

You can pass it in as part of the LinearLayout.LayoutParams constructor:

LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
    LayoutParams.MATCH_PARENT,
    LayoutParams.MATCH_PARENT,
    1.0f
);
YOUR_VIEW.setLayoutParams(param);

The last parameter is the weight.

Sunday, June 6, 2021
 
seaders
answered 6 Months ago
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