Java 如何在GridLayout中获得与GridView类似的选定子项
我想达到以下能力:Java 如何在GridLayout中获得与GridView类似的选定子项,java,android,android-adapter,grid-layout,view-hierarchy,Java,Android,Android Adapter,Grid Layout,View Hierarchy,我想达到以下能力: 通过长时间单击GridLayout,每次仅在GridLayout中选择一个子View 单击GridLayout或可视化层次结构中的任何父级将取消选择所选子级视图(如果已选择) 问题在于注册视图时。仅长按Listener回调到子视图,单击时既不会调用父GridLayout,也不会调用任何祖先注册的回调(无论是视图。OnClickListener还是视图。onTouchEvent) 如何在GridLayout中获得与AdapterView.OnItemSelectedList
- 通过长时间单击
,每次仅在GridLayout
中选择一个子GridLayout
View
- 单击
或可视化层次结构中的任何父级将取消选择所选子级GridLayout
(如果已选择)视图
视图时。仅长按Listener
回调到子视图
,单击时既不会调用父GridLayout
,也不会调用任何祖先注册的回调(无论是视图。OnClickListener
还是视图。onTouchEvent
)
如何在
GridLayout
中获得与AdapterView.OnItemSelectedListener
或AdapterView.OnItemLongClickListener
类似的选定子级并解决上述问题?使用以下代码:
int last_pos = -1;
GridLayout gridLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridLayout = (GridLayout) findViewById(R.id.gridLayout);
int child_count = gridLayout.getChildCount();
for(int i =0;i<child_count;i++){
gridLayout.getChildAt(i).setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
//Deselect previous
if(last_pos!=-1) gridLayout.getChildAt(last_pos).setSelected(false);
//Select the one you clicked
view.setSelected(true);
last_pos = gridLayout.indexOfChild(view);
return false;
}
});
}
//Remove focus if the parent is clicked
gridLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
gridLayout.getChildAt(last_pos).setSelected(false);
}
});
int last_pos=-1;
网格布局;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridLayout=(gridLayout)findViewById(R.id.gridLayout);
int child_count=gridLayout.getChildCount();
对于(int i=0;i使用以下代码:
int last_pos = -1;
GridLayout gridLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridLayout = (GridLayout) findViewById(R.id.gridLayout);
int child_count = gridLayout.getChildCount();
for(int i =0;i<child_count;i++){
gridLayout.getChildAt(i).setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
//Deselect previous
if(last_pos!=-1) gridLayout.getChildAt(last_pos).setSelected(false);
//Select the one you clicked
view.setSelected(true);
last_pos = gridLayout.indexOfChild(view);
return false;
}
});
}
//Remove focus if the parent is clicked
gridLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
gridLayout.getChildAt(last_pos).setSelected(false);
}
});
int last_pos=-1;
网格布局;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridLayout=(gridLayout)findViewById(R.id.gridLayout);
int child_count=gridLayout.getChildCount();
对于(int i=0;i如何将“选定”视图存储为全局变量,并在其焦点改变时将其删除?通过使用focusable
、focusableInTouchMode
和onClick
监听器,您可以得到正确的结果。我不确定这是最佳解决方案,但它可以工作
您需要什么:
- 全局视图变量:选中的
网格布局
的子项长时间单击
- (可选)自定义父容器作为任何
视图组
:它将在其所有子对象[*]上设置聚焦侦听器。在我的测试中,我使用了线性布局
和相对布局
[*]如果不使用可选的父自定义类,则必须在父视图组的所有子级上设置android:focusableInTouchMode=“true”和android:focusableInTouchMode=“true”
,并且必须设置OnClickListener
才能调用removeViewSelected()
单击父视图组时
- 添加单击
GridLayout
子项的侦听器:更新所选视图
- 实现一个焦点侦听器:如果选定视图失去焦点,它将删除该视图
它将处理父层次结构和子层次结构上的所有焦点更改状态,请参见输出:
我使用了以下模式:
CoordinatorLayout --- simple root group
ParentLayout --- aka "parentlayout"
Button --- simple Button example
GridLayout --- aka "gridlayout"
FloattingActionButton --- simple Button example
让我们在活动中准备选定的视图
及其更新方法
:
private View selectedView;
...
private void setViewSelected(View view) {
removeViewSelected();
selectedView = view;
if (selectedView != null) {
// change to a selected background for example
selectedView.setBackgroundColor(
ContextCompat.getColor(this, R.color.colorAccent));
}
}
private View getViewSelected() {
if (selectedView != null) {
return selectedView;
}
return null;
}
private void removeViewSelected() {
if (selectedView != null) {
// reset the original background for example
selectedView.setBackgroundResource(R.drawable.white_with_borders);
selectedView = null;
}
// clear and reset the focus on the parent
parentlayout.clearFocus();
parentlayout.requestFocus();
}
在每个GridLayout
子项上,添加单击
和长单击
侦听器以更新或删除所选视图。我的视图是动态添加的TextView
s,但您可以轻松创建for循环来检索子项:
TextView tv = new TextView(this);
...
gridlayout.addView(tv);
tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
removeViewSelected();
}
});
tv.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
setViewSelected(view);
return true;
}
});
在父容器上设置FocusChange
侦听器:
parentlayout.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean hasFocus) {
View viewSelected = getViewSelected();
// if the selected view exists and it lost focus
if (viewSelected != null && !viewSelected.hasFocus()) {
// remove it
removeViewSelected();
}
}
});
然后,可选的自定义视图组
:它是可选的,因为您可以通过XML和可单击的
侦听器动态设置可聚焦的
状态,但对我来说似乎更容易。我使用以下自定义类
作为父容器:
public class ParentLayout extends RelativeLayout implements View.OnClickListener {
public ParentLayout(Context context) {
super(context);
init();
}
public ParentLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public ParentLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
// handle focus and click states
public void init() {
setFocusable(true);
setFocusableInTouchMode(true);
setOnClickListener(this);
}
// when positioning all children within this
// layout, add their focusable state
@Override
protected void onLayout(boolean c, int l, int t, int r, int b) {
super.onLayout(c, l, t, r, b);
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
child.setFocusable(true);
child.setFocusableInTouchMode(true);
}
// now, even the Button has a focusable state
}
// handle the click events
@Override
public void onClick(View view) {
// clear and set the focus on this viewgroup
this.clearFocus();
this.requestFocus();
// now, the focus listener in Activity will handle
// the focus change state when this layout is clicked
}
}
公共类ParentLayout扩展了RelativeLayout实现View.OnClickListener{
公共父布局(上下文){
超级(上下文);
init();
}
公共父布局(上下文、属性集属性){
超级(上下文,attrs);
init();
}
公共父布局(上下文上下文、属性集属性、int-defStyleAttr){
super(上下文、attrs、defStyleAttr);
init();
}
//处理焦点并单击状态
公共void init(){
设置聚焦(真);
setFocusableInTouchMode(真);
setOnClickListener(此);
}
//当将所有子项放置在此
//布局,添加其可聚焦状态
@凌驾
仅受保护的void布局(布尔c、int l、int t、int r、int b){
超级在线布局(c、l、t、r、b);
最终整数计数=getChildCount();
for(int i=0;i
例如,这是我使用的布局:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout ...>
<com.app.ParentLayout
android:id="@+id/parent_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal">
<Button
android:id="@+id/sample_button"
android:layout_width="250dp"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
android:text="A Simple Button"
android:layout_marginTop="20dp"
android:layout_marginBottom="20dp"/>
<android.support.v7.widget.GridLayout
android:id="@+id/grid_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:layout_above="@id/sample_button" .../>
</com.app.ParentLayout>
<android.support.design.widget.FloatingActionButton .../>
</android.support.design.widget.CoordinatorLayout>
希望这会有用。如何将“选定”视图存储为全局变量,并在其焦点改变时将其删除?通过使用focusable
、focusableInTouchMode
和onClick
监听器,您可以获得正确的结果。我不确定这是最佳解决方案,但它是有效的
您需要什么:
- 全局视图变量:选中的
网格布局
的子项长时间单击
- (可选)自定义父容器作为任何
视图组
:它将在其所有子对象[*]上设置可聚焦的侦听器