如何在展开式视图中为各个组名设置不同的背景颜色?
我有代码创建具有组名的组 - 组1到组10.每个组都有子项 - 子项1到子项3.
我想根据群组名称为每个群组及其子群提供不同的背景颜色。如果未满足条件,则默认为黑色
例如:
第1组 - 白色背景
第2组 - 红色背景
第3组 - 灰色背景
第4组 - 黄色背景
main.XML:可扩展列表布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<ExpandableListView
android:id="@+id/expandable_list"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<ListView
android:id="@+id/android:list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:choiceMode="multipleChoice" />
</LinearLayout>
grouprow.xml:组文字布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:id="@+id/rowname"
android:paddingLeft="50px"
android:textSize="30px"
android:textColor="@drawable/blue"
android:textStyle="normal"
android:layout_width="fill_parent"
android:layout_height="50px"/>
</LinearLayout>
childrow.xml:子文字布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView android:id="@+id/grpchild"
android:paddingLeft="50px"
android:focusable="false"
android:textSize="14px"
android:textStyle="normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
父组类:用于创建每个父项的类
public class CategoryGroup {
private String mTitle;
private ArrayList<String> mArrayChildren;
public String getTitle() {
return mTitle;
}
public void setTitle(String mTitle) {
this.mTitle = mTitle;
}
public ArrayList<String> getArrayChildren() {
return mArrayChildren;
}
public void setArrayChildren(ArrayList<String> mArrayChildren) {
this.mArrayChildren = new ArrayList(mArrayChildren);
}
}
可扩展列表类
public class ExpandableListItems extends BaseExpandableListAdapter {
private LayoutInflater inflater;
private ArrayList<CategoryGroup> mParent;
public ExpandableListItems(Context context, ArrayList<CategoryGroup> parent) {
mParent = parent;
inflater = LayoutInflater.from(context);
}
@Override
//counts the number of group/parent items so the list knows how many times calls getGroupView() method
public int getGroupCount() {
return mParent.size();
}
@Override
//counts the number of children items so the list knows how many times calls getChildView() method
public int getChildrenCount(int i) {
return mParent.get(i).getArrayChildren().size();
}
@Override
//gets the title of each parent/group
public Object getGroup(int i) {
return mParent.get(i).getTitle();
}
@Override
//gets the name of each item
public Object getChild(int i, int i1) {
return mParent.get(i).getArrayChildren().get(i1);
}
@Override
public long getGroupId(int i) {
return i;
}
@Override
public long getChildId(int i, int i1) {
return i1;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
//in this method you must set the text to see the parent/group on the list
public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
if (view == null) {
System.out.println("i: " + i + "; b: " + b );
view = inflater.inflate(R.layout.grouprow, viewGroup, false);
}
TextView textView = (TextView) view.findViewById(R.id.rowname);
//"i" is the position of the parent/group in the list
textView.setText(getGroup(i).toString());
//return the entire view
return view;
}
@Override
//in this method you must set the text to see the children on the list
public View getChildView(int i, int i1, boolean b, View view, ViewGroup viewGroup) {
if (view == null) {
view = inflater.inflate(R.layout.childrow, viewGroup, false);
}
TextView textView = (TextView) view.findViewById(R.id.grpchild);
//"i" is the position of the parent/group in the list and
//"i1" is the position of the child
textView.setText(mParent.get(i).getArrayChildren().get(i1));
//return the entire view
return view;
}
@Override
public boolean isChildSelectable(int i, int i1) {
return true;
}
@Override
public void registerDataSetObserver(DataSetObserver observer) {
/* used to make the notifyDataSetChanged() method work */
super.registerDataSetObserver(observer);
}
}
主要活动类:
public class GetResourcesListActivity extends ListActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
private ExpandableListView mExpandableList;
private ExpandableListItems mAdapter;
ArrayList<CategoryGroup> arrayParentsGroups = new ArrayList<CategoryGroup>();
mExpandableList = (ExpandableListView)findViewById(R.id.expandable_list);
arrayParents = createGroupList();
mAdapter = new ExpandableListItems(this, arrayParentsGroups);
mExpandableList.setAdapter(mAdapter);
private List createGroupList() {
ArrayList arrayParents = new ArrayList();
for( int i = 0 ; i < 10 ; ++i ) { // 10 groups........
CategoryGroup parent = new CategoryGroup();
parent.setTitle("Group" + i);
ArrayList<String> arrayChildren = new ArrayList<String>();
for (int j = 0; j < 3; j++) {
arrayChildren.add("Child " + j);
}
parent.setArrayChildren(arrayChildren);
arrayParents.add(parent);
}
return arrayParents;
}
}
)
答案 0 :(得分:1)
以下是一种简单的方法。
为您的CategoryGroup
对象提供另一个名为int mBackgroundRes
的属性。还要添加相应的getter和setter方法。
在createGroupList()
方法中,您可以根据逻辑设置后台资源:
private ArrayList<CategoryGroup> createGroupList() {
ArrayList arrayParents = new ArrayList();
for (int i = 0; i < 10; ++i) { // 10 groups........
CategoryGroup parent = new CategoryGroup();
parent.setTitle("Group" + i);
int background = android.R.color.black;
if (i == 0) {
background = android.R.color.white;
} else if (i == 1) {
background = android.R.color.holo_red_light;
} else if (i == 2) {
background = android.R.color.darker_gray;
}
parent.setBackgroundRes(background);
ArrayList<String> arrayChildren = new ArrayList<String>();
for (int j = 0; j < 3; j++) {
arrayChildren.add("Child " + j);
}
parent.setArrayChildren(arrayChildren);
arrayParents.add(parent);
}
return arrayParents;
}
最后,在BaseExpandableListAdapter
更改getGroup()
方法以返回正确的对象类型。您可以简单地将Object
更改为CategoryGroup
:
@Override
public CategoryGroup getGroup(int i) {
return mParent.get(i);
}
并在getGroupView()
和getChildView()
方法的相应视图中设置背景:
@Override
public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
if (view == null) {
System.out.println("i: " + i + "; b: " + b);
view = inflater.inflate(R.layout.grouprow, viewGroup, false);
}
view.setBackgroundResource(getGroup(i).getBackgroundRes());
TextView textView = (TextView) view.findViewById(R.id.rowname);
textView.setText(getGroup(i).getTitle());
return view;
}
@Override
public View getChildView(int i, int i1, boolean b, View view,
ViewGroup viewGroup) {
if (view == null) {
view = inflater.inflate(R.layout.childrow, viewGroup, false);
}
view.setBackgroundResource(getGroup(i).getBackgroundRes());
TextView textView = (TextView) view.findViewById(R.id.grpchild);
textView.setText(mParent.get(i).getArrayChildren().get(i1));
return view;
}
答案 1 :(得分:0)
将适配器更新为以下内容:
@Override
//in this method you must set the text to see the parent/group on the list
public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
if (view == null) {
System.out.println("i: " + i + "; b: " + b );
view = inflater.inflate(R.layout.grouprow, viewGroup, false);
switch(i){ // i is the groupPosition - 0-based indexing
case 0: view.setBackgroundColor(android.R.color.white); break;
case 1: view.setBackgroundColor(android.R.color.holo_dark_red); break;
...
}
}
TextView textView = (TextView) view.findViewById(R.id.rowname);
//"i" is the position of the parent/group in the list
textView.setText(getGroup(i).toString());
//return the entire view
return view;
}
如果提供的颜色不够(android.R.color.xxx
),那么您可以制作自己的颜色。
在res / values中创建一个名为colors.xml的新文件,然后定义自己的颜色:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="white">#FFFFFF</color>
<color name="yellow">#FFFF00</color>
<color name="red">#FF0000</color>
<color name="gray">#808080</color>
<color name="purple">#800080</color>
<color name="green">#008000</color>
<color name="blue">#0000FF</color>
<color name="black">#000000</color>
</resources>
然后您可以在代码中引用它们,如下所示:
view.setBackgroundColor(R.color.blue);
编辑:如果不能以这种方式工作,请使用已解析的颜色尝试:
view.setBackgroundColor(getResources().getColor(android.R.color.white));
我刚刚粘贴到我自己的ExpandableListView
并没有问题。