有没有办法让ellipsize ="marquee"总是滚动？

Question

我想在TextView上使用选取框效果,但只有在TextView获得焦点时才会滚动文本.这是一个问题,因为在我的情况下,它不能.

我在用:

  android:ellipsize="marquee"
  android:marqueeRepeatLimit="marquee_forever"

有没有办法让TextView始终滚动其文本？我已经看到这是在Android Market应用程序中完成的,其中应用程序名称将在标题栏中滚动,即使它没有获得焦点,但我无法在API文档中找到这一点.

Answer 1

我今天终于遇到了这个问题,因此hierarchyviewer在Android Market应用程序上激动了.

在应用程序的详细信息屏幕上查看标题,它们使用的是旧版本TextView.检查其属性表明,它不集中,不能集中和普遍很普通-除了事实,即它被标记为选中.

一行代码后来我工作了:)

textView.setSelected(true);

考虑到Javadoc的说法,这是有道理的:

可以选择或不选择视图.请注意,选择与焦点不同.视图通常在AdapterView(如ListView或GridView)的上下文中选择.

即,当您在列表视图中滚动项目时(例如在市场应用程序中),只有那时现在选择的文本才会开始滚动.而且由于这个特殊TextView功能无法集中或可点击,因此它永远不会失去其选择状态.

不幸的是,据我所知,没有办法从布局XML预先设置选定的状态.
但上面的单线程对我来说很好.

Answer 2

只需将这些参数放在TextView中即可.有用 :)

    android:singleLine="true" 
    android:ellipsize="marquee"
    android:marqueeRepeatLimit ="marquee_forever"
    android:scrollHorizontally="true"
    android:focusable="true"
    android:focusableInTouchMode="true" 

Answer 3

我一直面临着这个问题,我提出的最简单的解决方案是创建一个从TextView派生的新类.该类应该覆盖onFocusChanged,onWindowFocusChanged和isFocused三个方法,以使TextView全部聚焦.

@Override
protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
    if(focused)
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
}

@Override
public void onWindowFocusChanged(boolean focused) {
    if(focused)
        super.onWindowFocusChanged(focused);
}


@Override
public boolean isFocused() {
    return true;
}

Answer 4

TranslateAnimation通过在一个方向上"拉"视图指定的量来工作.您可以设置从哪里开始"拉动"以及从何处结束.

TranslateAnimation(fromXDelta, toXDelta, fromYDelta, toYDelta);

fromXDelta设置X轴上运动起始位置的偏移量.

fromXDelta = 0 //no offset. 
fromXDelta = 300 //the movement starts at 300px to the right.
fromXDelta = -300 //the movement starts at 300px to the left

toXDelta定义X轴上运动的偏移结束位置.

toXDelta = 0 //no offset. 
toXDelta = 300 //the movement ends at 300px to the right.
toXDelta = -300 //the movement ends at 300px to the left.

如果文本的宽度大于fromXDelta和toXDelta之间差异的模块,则文本将无法在屏幕内完全和强制移动.

例

我们假设我们的屏幕尺寸为320x240像素.我们有一个TextView,其文本宽度为700px,我们希望创建一个"拉动"文本的动画,以便我们可以看到短语的结尾.

                                       (screen)
                             +---------------------------+
                             |<----------320px---------->|
                             |                           |
                             |+---------------------------<<<< X px >>>>
               movement<-----|| some TextView with text that goes out...
                             |+---------------------------
                             |  unconstrained size 700px |
                             |                           |
                             |                           |
                             +---------------------------+


                             +---------------------------+
                             |                           |
                             |                           |
               <<<< X px >>>>---------------------------+|
movement<----- some TextView with text that goes out... ||
                             ---------------------------+|
                             |                           |
                             |                           |
                             |                           |
                             +---------------------------+

首先,我们设置fromXDelta = 0为运动没有起始偏移量.现在我们需要计算toXDelta值.为了达到预期的效果,我们需要将文本"拉"出与屏幕完全相同的px.(在该方案中由<<<< X px >>>>表示)由于我们的文本有700宽度,可见区域是320px(屏幕宽度),我们设置:

tXDelta = 700 - 320 = 380

我们如何计算屏幕宽度和文字宽度？

码

以Zarah Snippet为出发点:

    /**
     * @param view The Textview or any other view we wish to apply the movement
     * @param margin A margin to take into the calculation (since the view
     *               might have any siblings in the same "row")
     *
     **/
public static Animation scrollingText(View view, float margin){

    Context context = view.getContext(); //gets the context of the view

            // measures the unconstrained size of the view
            // before it is drawn in the layout
    view.measure(View.MeasureSpec.UNSPECIFIED, 
                         View.MeasureSpec.UNSPECIFIED); 

            // takes the unconstrained wisth of the view
    float width = view.getMeasuredWidth();

            // gets the screen width
    float screenWidth = ((Activity) context).getWindowManager().getDefaultDisplay().getWidth();


            // perfrms the calculation
    float toXDelta = width - (screenWidth - margin);

            // sets toXDelta to 0 if the text width is smaller that the screen size
    if (toXDelta < 0) {toXDelta = 0; } else { toXDelta = 0 - toXDelta;}

            // Animation parameters
    Animation mAnimation = new TranslateAnimation(0, toXDelta, 0, 0);
    mAnimation.setDuration(15000); 
    mAnimation.setRepeatMode(Animation.RESTART);
    mAnimation.setRepeatCount(Animation.INFINITE);

    return mAnimation;
}

可能有更简单的方法来执行此操作,但这适用于您可以想到并且可重用的每个视图.如果您想要在ListView中为TextView设置动画而不破坏textView的enabled/onFocus功能,这将非常有用.即使视图没有聚焦,它也会连续滚动.

Answer 5

我不知道你是否还需要答案,但我找到了一个简单的方法.

像这样设置你的动画:

Animation mAnimation = new TranslateAnimation(START_POS_X, END_POS_X, 
                START_POS_Y, END_POS_Y);
mAnimation.setDuration(TICKER_DURATION); 
mAnimation.setRepeatMode(Animation.RESTART);
mAnimation.setRepeatCount(Animation.INFINITE);

START_POS_X,END_POS_X,START_POS_Y和END_POS_Y是float价值观,同时TICKER_DURATION是一个int与我的其他常量声明我.

然后,您现在可以将此动画应用于TextView:

TextView tickerText = (TextView) findViewById(R.id.ticker);
tickerText.setAnimation(mAnimation);

就是这样.:)

我的动画在屏幕右侧(300f)开始,在屏幕左侧(-300f)结束,持续时间为15s(15000).

Answer 6

我为带有选框文本项的ListView编写了以下代码.它基于上面描述的setSelected解决方案.基本上,我正在扩展ArrayAdapter类并覆盖getView方法以在返回之前选择TextView:

    // Create an ArrayAdapter which selects its TextViews before returning      
    // them. This would enable marqueeing while still making the list item
    // clickable.
    class SelectingAdapter extends ArrayAdapter<LibraryItem>
    {
        public
        SelectingAdapter(
            Context context, 
            int resource, 
            int textViewResourceId, 
            LibraryItem[] objects
        )
        {
            super(context, resource, textViewResourceId, objects);
        }

        @Override
        public
        View getView(int position, View convertView, ViewGroup parent)
        {
            View view = super.getView(position, convertView, parent);
            TextView textview = (TextView) view.findViewById(
                R.id.textview_playlist_item_title
            );
            textview.setSelected(true);
            textview.setEnabled(true);
            textview.setFocusable(false);
            textview.setTextColor(0xffffffff);
            return view;

        }
    }