为什么在视图上调用setBackgroundColor打破其长按颜色变化，并强调？ [英] Why does calling setBackgroundColor on a view break its long click color change and highlighting?

问题描述

在Android中，默认情况下，当你长按上一个列表项，它会从高亮颜色为白色，表明用户已举行了下来，一个上下文项目将被显示出来。此外，您还可以使用轨迹球（或箭头在某些手机上的按钮），选择列表中的项目而不是用你的手指。

不过，我有一个ListView的项目的意见，我呼吁setBackgroundColor，都与预期的行为不再起作用。任何人都知道这是为什么，以及如何解决它？

注：设置在XML的背景颜色是不是一种选择，因为我需要能够动态设置/改变颜色

。

在code为我NewView的功能如下：

  @覆盖
公共查看NewView的（上下文CTX，光标光标的ViewGroup父）
{
    查看查看=新景（mCtx）;
    最后LayoutInflater李=（LayoutInflater）mCtx.getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
    鉴于= li.inflate（R.layout.task_list_item，NULL）;    返回视图。
}
 

解决方案

默认情况下，的ListView 有一个选择这将起到 TransitionDrawable 当你长preSS列表项。但是，如果你的列表项视图有一个坚实的背景，那么你将无法看到选择的长期preSS动画（或任何其他国家），因为它涵盖了由列表项的背景。

如果你想看到选择的长期preSS动画/选择/ pressed状态，则列表项的必须有项目时所选的透明背景/ pressed /长pressed。您可以通过使用做一个<一个href=\"http://developer.android.com/reference/android/graphics/drawable/StateListDrawable.html\">StateListDrawable为您的项目的背景，而不是纯色。

下面是<一个样本href=\"http://developer.android.com/reference/android/graphics/drawable/StateListDrawable.html\">StateListDrawable为此目的：

 公共类ColorfulListItemDrawable扩展StateListDrawable {
    私人最终PaintDrawable mColor;    公共ColorfulListItemDrawable（INT颜色）{
        mColor =新PaintDrawable（彩色）;
        初始化（）;
    }
    私人无效初始化（）{
        可绘制彩色= mColor;
        可绘制选择=新ColorDrawable（Color.TRANSPARENT）;
        addState（新INT [] {android.R.attr.state_ pressed，android.R.attr.state_enabled，
                android.R.attr.state_window_focused}，选择）;
        addState（新INT [] {android.R.attr.state_ pressed，android.R.attr.state_enabled，
                android.R.attr.state_window_focused，android.R.attr.state_selected}，选择）;
        addState（新INT [] {android.R.attr.state_enabled，android.R.attr.state_window_focused，android.R.attr.state_selected}，选择）;
        addState（新INT [] {}，颜色）;
    }
    公共无效的setColor（INT颜色）{
        。mColor.getPaint（）的setColor（彩色）;
        mColor.invalidateSelf（）;
    }
}
 

In Android, by default when you long click on a list item, it goes from the highlight color to white indicating that the user has held it down and a context item will be displayed. Also, you can use the trackball (or arrow buttons on some phones) to select list items rather then using your fingers.

However, I have a ListView whose item's views I am calling setBackgroundColor on, and both of those expected behaviors no longer work. Anybody know why this is and how to fix it?

Notes: Setting the background color in the xml is not an option because I need to be able to set/change the color dynamically.

The code for my newView function is as follows:

@Override
public View newView(Context ctx, Cursor cursor, ViewGroup parent)
{
    View view = new View(mCtx);
    final LayoutInflater li = (LayoutInflater) mCtx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    view = li.inflate(R.layout.task_list_item, null);

    return view;
}

解决方案

By default, ListView has a Selector that will play a TransitionDrawable when you longpress a list item. However, if your list item view has a solid background, then you won't be able to see the selector's longpress animation (or on any other states) , because it's covered up by the list item's background.

If you want to see the selector's longpress animation/selected/pressed state, then the list item's has to have a transparent background when the item is selected/pressed/longpressed. You can do it by using a StateListDrawable as your item's background instead of a solid color.

Here is a sample of StateListDrawable for that purpose:

public class ColorfulListItemDrawable extends StateListDrawable {
    private final PaintDrawable mColor;

    public ColorfulListItemDrawable(int color) {
        mColor = new PaintDrawable(color);
        initialize();
    }
    private void initialize() {
        Drawable color = mColor;
        Drawable selected = new ColorDrawable(Color.TRANSPARENT);
        addState(new int[] {android.R.attr.state_pressed, android.R.attr.state_enabled, 
                android.R.attr.state_window_focused}, selected);
        addState(new int[] {android.R.attr.state_pressed, android.R.attr.state_enabled, 
                android.R.attr.state_window_focused,android.R.attr.state_selected}, selected);
        addState(new int[] {android.R.attr.state_enabled,android.R.attr.state_window_focused, android.R.attr.state_selected}, selected);
        addState(new int[] {}, color);
    }
    public void setColor(int color) {
        mColor.getPaint().setColor(color);
        mColor.invalidateSelf();
    }   
}

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