Add a ProgressBar programatically to a Fragment in

问题:

I was able to manipulate some text of an existing TextView in a Fragment. However I was not able to programatically add a new ProgressBar to the existing layout.
In the Fragment class:

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_completed_office_hours, container, false);

        LinearLayout linearLayout = (LinearLayout) view.findViewById(R.id.linearLayoutCompletedOfficeHours);

        progressBar = new ProgressBar(this.getContext());
        progressBar.setMax(daysInTotal);
        progressBar.setProgress(daysCompleted);

        linearLayout.addView(progressBar);

        TextView textView = (TextView) view.findViewById(R.id.completedXOfYDays);
        textView.setText(daysCompleted + " / " + daysInTotal);
        return view;
    }

The xml:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragment.CompletedOfficeHoursFragment">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="@dimen/activity_horizontal_margin"
        android:orientation="horizontal"
        android:id="@+id/linearLayoutCompletedOfficeHours">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/completedXOfYDays" />
    </LinearLayout>
</FrameLayout>

When executing it I get 19 / 299 as text, but without any ProgressBar. What am I doing wrong=

回答1:

It is not showing because you did not specify its child's layout_param and therefore will result to parent not displaying it.

You need to specify the layout params of the child view you want to attach.

progressBar = new ProgressBar(this.getContext());
progressBar.setMax(daysInTotal);
progressBar.setProgress(daysCompleted);
progressBar.setLayoutParams(new LinearLayout.LayoutParams(MATCH_PARENT, WRAP_CONTENT));

回答2:

You have specified "linearLayoutCompletedOfficeHours" as a Linear Layout with android:orientation="horizontal" and given textview android:layout_width="match_parent".Making this will make textview to take entire space and progressbar is created and shown in the screen. Instead change textView width to android:layout_width="wrap_content" and the progress will be visible.

<TextView
   android:layout_width="wrap_content"
   android:layout_height="match_parent"
   android:id="@+id/completedXOfYDays" />