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I've got an Android Switch which when turned on, expands a LinearLayout below it. For this I use an animation. When I start the screen the button is turned off, but the LinearLayout is shown. When I now turn the Switch to on, and then back off again, it indeed hides the LinearLayout, but like I said, whenever the screen starts, the LinearLayout is shown by default. Does anybody know how I can hide the LinearLayout by default when the screen starts?

The code I have now is as follows:

public class MyClass extends Activity implements OnCheckedChangeListener {
    Switch mySwitch;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_layout);

        mySwitch = (Switch) findViewById(R.id.my_switch);
        mySwitch.setOnCheckedChangeListener(this);
    }

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if (isChecked){
            LinearLayout view = (LinearLayout) findViewById(R.id.view_to_expand);
            Animation anim = expand(view, true);
            view.startAnimation(anim);
        }
        else {
            LinearLayout view = (LinearLayout) findViewById(R.id.view_to_expand);
            Animation anim = expand(view, false);
            view.startAnimation(anim);
        }
    }

    public static Animation expand(final View v, final boolean expand) {
        try {
            Method m = v.getClass().getDeclaredMethod("onMeasure", int.class, int.class);
            m.setAccessible(true);
            m.invoke(v, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(((View) v.getParent()).getMeasuredWidth(), MeasureSpec.AT_MOST));
        } catch (Exception e) {
            e.printStackTrace();
        }
        final int initialHeight = v.getMeasuredHeight();
        if (expand) {
            v.getLayoutParams().height = 0;
        } else {
            v.getLayoutParams().height = initialHeight;
        }
        v.setVisibility(View.VISIBLE);
        Animation a = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime,
                    Transformation t) {
                int newHeight = 0;
                if (expand) {
                    newHeight = (int) (initialHeight * interpolatedTime);
                } else {
                    newHeight = (int) (initialHeight * (1 - interpolatedTime));
                }
                v.getLayoutParams().height = newHeight;
                v.requestLayout();
                if (interpolatedTime == 1 && !expand)
                    v.setVisibility(View.GONE);
            }

            @Override
            public boolean willChangeBounds() {
                return true;
            }
        };
        a.setDuration(250);
        return a;
    }
}
4

1 に答える 1

2

ViewSwitcher を使用してみることができます。それをxmlレイアウトに追加し、それにLinearLayoutを追加し、空のレイアウトも追加します。アプリケーションの開始時に、空のレイアウトから開始してから、別のレイアウトに切り替えることができます

<ViewSwitcher xmlns:android = "http://schemas.android.com/apk/res/android"
    android:id="@+id/layoutSwitcher"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <LinearLayout></LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:padding="6dip" >

        <ImageView.... 
    </<LinearLayout>
</ViewSwitcher>

次に、コードで

switcher = (ViewSwitcher) findViewById(R.id.layoutSwitcher);
switcher.showNext();
于 2013-10-06T21:16:05.967 に答える