如何使用ExpandableListView工作？ [英] How to work with ExpandableListView?

问题描述

惠康所有

我有我测试ExpanableListView。我有一个项目的展开图标的问题。该图标被绘制覆盖每个项目的文字标题。这意味着，例如，如果第一项的标题是Ducados，图标被覆盖杜，只有cados是可见的

I have a ExpanableListView that i'm testing. I have a problem with the expand icon of the items. The icon is being painted overlaying the text title of each item. It means that for example, if the title of the first items is "Ducados", the icon is overlaying "Du" and only "cados" is visible

我能做些什么来对准展开图标的吧？

What can i do to align the text on the right of the expand icon?

这是code：

public class MainActivity extends ExpandableListActivity {
ExpandableListAdapter mAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Set up our adapter
    mAdapter = new MyExpandableListAdapter();
    setListAdapter(mAdapter);
    registerForContextMenu(getExpandableListView());
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
    menu.setHeaderTitle("Sample menu");
    menu.add(0, 0, 0, "Sample action");
}

@Override
public boolean onContextItemSelected(MenuItem item) {
    ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();

    String title = ((TextView) info.targetView).getText().toString();

    int type = ExpandableListView.getPackedPositionType(info.packedPosition);
    if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
        int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);
        int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition);
        Toast.makeText(this, title + ": Child " + childPos + " clicked in group " + groupPos, Toast.LENGTH_SHORT).show();
        return true;
    } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
        int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);
        Toast.makeText(this, title + ": Group " + groupPos + " clicked", Toast.LENGTH_SHORT).show();
        return true;
    }

    return false;
}

public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    // Sample data set.  children[i] contains the children (String[]) for groups[i].
    private String[] groups = { "Names", "Designation", "Gender", "Company" };
    private String[][] children = {
            { "abc", "xyz", "ash", "anu" },
            { "SSE", "TJ", "PM", "SE" },
            { "Male", "Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female Female " },
            { "yyyyyy", "xxxxx" }
    };

    public Object getChild(int groupPosition, int childPosition) {
        return children[groupPosition][childPosition];
    }

    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    public int getChildrenCount(int groupPosition) {
        return children[groupPosition].length;
    }

    public TextView getGenericView() {
        // Layout parameters for the ExpandableListView
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);

        TextView textView = new TextView(MainActivity.this);
        textView.setLayoutParams(lp);
        textView.setTextSize(20);
        // Center the text vertically
        textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
        return textView;
    }

    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        TextView textView = getGenericView();
        textView.setText(getChild(groupPosition, childPosition).toString());
        textView.setTextSize(15);
        return textView;
    }

    public Object getGroup(int groupPosition) {
        return groups[groupPosition];
    }

    public int getGroupCount() {
        return groups.length;
    }

    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        TextView textView = getGenericView();
        textView.setText(getGroup(groupPosition).toString());
        return textView;
    }

    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    public boolean hasStableIds() {
        return true;
    }   
}
}

感谢

推荐答案

我记得运行到类似的问题在我自己的应用程序之一。

I remember running into a similar issue in one of my own apps.

在你的 getGenericView 方法，你可以使用<一个href=\"http://developer.android.com/reference/android/view/View.html#setPadding%28int,%20int,%20int,%20int%29\"相对=nofollow> TextView.setPadding ，以便它进一步显示在右侧，而不是由图标重叠来指定文本的左侧填充。由于该方法设置在像素的填充（这将取决于屏幕的密度），其向所述像素转换为密度独立像素使填充和外观是从屏幕标准化屏幕。

In your getGenericView method, you can use TextView.setPadding to specify the left padding of the text so that it appears further to the right, and is not overlapped by the icon. Since the method sets the padding in pixels (which will vary depending on the screen's density), it is important to convert the pixels to density-independent pixels so that the padding and appearance is standardized from screen to screen.

下面是从我自己的code中的方法的完整的例子：

Here's a full example of the method from my own code:

public TextView getGenericView() {
    // Padding values (in pixels)
    int left = 36; // to avoid being overlapped by the icon
    int right = 0; // not needed
    int top = 15; // space out the list a bit more
    int bottom = top; // space out the list a bit more

    // Get density of screen to convert px to dp
    float scale = m_Context.getResources().getDisplayMetrics().density;

    // Layout parameters for the ExpandableListView
    AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);

    TextView textView = new TextView(MyActivity.this);
    textView.setLayoutParams(lp);
    // Center the text vertically
    textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
    // Set the text starting position
    textView.setPadding((int)(left * scale), (int)(top * scale), right, (int)(bottom * scale)); // left, top, right, bottom
    textView.setTextSize(20);
    return textView;
}

如果您在整个你的应用程序的多个ExpandableListViews，它可能是最好指定在您的应用程序的资源（RES /价值/ dimen.xml），而不是在这里 getGenericView <顶部的像素大小/ code>，所以它是在一个地方定义（并且可以更改），你可以在所有列表引用它。

If you have multiple ExpandableListViews throughout your app, it may be better to specify the pixel sizes in the your app resources (res/values/dimen.xml) rather than here at the top of getGenericView, so that it is defined (and can be changed) in one place and you can reference it in all the lists.

希望这有助于！

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