我的开发环境包含用于ARM OMAP Sitata的g ++交叉编译器。当将unsigned int添加到unsigned int *时，我发现了一个简单的指针算法的不寻常的细微差别，如下所示：
public class ExpandableListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List<String> _listDataHeader; // header titles
// child data in format of header title, child title
private List<Integer> _group;
private DrawerLayout _drawer;
private static final int[] EMPTY_STATE_SET = {};
private static final int[] GROUP_EXPANDED_STATE_SET =
{android.R.attr.state_expanded};
private static final int[][] GROUP_STATE_SETS = {
EMPTY_STATE_SET, // 0
GROUP_EXPANDED_STATE_SET // 1
};
private HashMap<String, List<String>> _listDataChild;
ExpandableListView expandList;
public ExpandableListAdapter(Context context, List<String> listDataHeader, List<Integer> group,
HashMap<String, List<String>> listChildData, DrawerLayout drawer) {
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
this._group=group;
this._drawer=drawer;
}
@Override
public Object getChild(int groupPosition, int childPosititon) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition))
.get(childPosititon);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(final int groupPosition, final int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
final String childText = (String) getChild(groupPosition, childPosition);
int childpositionaa= (int) getChildId(groupPosition,childPosition);
int gropuposi= (int) getGroupId(groupPosition);
Log.i("groupposi", String.valueOf(+groupPosition));
Log.i("groupposicc", String.valueOf(+childPosition));
Log.i("groupposiccee", String.valueOf(+childpositionaa));
int child3position=(int)getChildId(1,childPosition);
Log.i("groupposiccee33", String.valueOf(+child3position));
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.list_item, null);
}
Log.i("childposition",""+childPosition);
Typeface roboto = Typeface.createFromAsset(_context.getAssets(),
"font/Roboto-Light.ttf");
AppCompatTextView txtListChild = (AppCompatTextView) convertView
.findViewById(R.id.lblListItem);
txtListChild.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()) {
case MotionEvent.ACTION_DOWN:
_drawer.closeDrawer(GravityCompat.START);
switch (groupPosition) {
case 0:
break;
case 1:
switch (childPosition){
case 0:
BaseActivity.dointent(_context.getApplicationContext(),Handled_follow.class);
break;
case 1:
BaseActivity.dointent(_context.getApplicationContext(), Unhanded_follow.class);
break;
case 2:
BaseActivity.dointent(_context.getApplicationContext(), Navi_recyview.class);
break;
case 3:
BaseActivity.dointent(_context.getApplicationContext(), Unhandled_appoint.class);
break;
case 4:
BaseActivity.dointent(_context.getApplicationContext(), Cold_calls.class);
break;
}
break;
}
break;
}
return false;
}
});
AppCompatTextView txtchildcount= (AppCompatTextView) convertView
.findViewById(R.id.lblistnavcount);
txtListChild.setText(childText);
txtListChild.setTypeface(roboto);
txtchildcount.setText(myList.get(childpositionaa));
if(gropuposi==2){
if(childpositionaa==0){
txtchildcount.setText(myList.get(5));
}
else{
txtchildcount.setText(myList.get(4));
}
txtchildcount.setText(myList.get(childpositionaa+5));
}
else{
txtchildcount.setText(myList.get(childpositionaa));
}
return convertView;
}
@Override
public int getChildrenCount(int groupPosition) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition))
.size();
}
@Override
public Object getGroup(int groupPosition) {
return this._listDataHeader.get(groupPosition);
}
@Override
public int getGroupCount() {
return this._listDataHeader.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(final int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
String headerTitle = (String) getGroup(groupPosition);
int headerimg = _group.get(groupPosition);
Log.i("groupposigroupview", String.valueOf(+groupPosition));
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.list_group, null);
}
AppCompatTextView lblListHeader = (AppCompatTextView) convertView
.findViewById(R.id.lblListHeader);
View ind = convertView.findViewById( R.id.indicicon);
if( ind != null ) {
ImageView indicator = (ImageView)ind;
if( getChildrenCount( groupPosition ) == 0 ) {
indicator.setVisibility( View.INVISIBLE );
} else {
indicator.setVisibility(View.VISIBLE);
if (isExpanded) {
lblListHeader.setTextColor(_context.getResources().getColor(R.color.colorPrimary));
indicator.setImageResource(R.drawable.ic_expand_less_black_18dp);
} else {
lblListHeader.setTextColor(_context.getResources().getColor(R.color.colorlisthead));
indicator.setImageResource(R.drawable.ic_expand_more_black_18dp);
}
}
}
Typeface roboto = Typeface.createFromAsset(_context.getAssets(),
"font/Roboto-Regular.ttf"); //use this.getAssets if you are calling from an Activity
lblListHeader.setTypeface(roboto);
lblListHeader.setText(headerTitle);
ImageView imgsListHeader = (ImageView) convertView
.findViewById(R.id.imagview);
imgsListHeader.setImageResource(headerimg);
lblListHeader.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()) {
case MotionEvent.ACTION_DOWN:
switch (groupPosition) {
case 0:
_drawer.closeDrawer(GravityCompat.START);
BaseActivity.dointent(_context.getApplicationContext(),Dashboard.class);
break;
case 1:
break;
case 2:
case 3:
_drawer.closeDrawer(GravityCompat.START);
break;
case 4:
_drawer.closeDrawer(GravityCompat.START);
break;
}
break;
}
return false;
}
});
return convertView;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
`
只是尝试将（unsigned int）添加到（unsigned int *）
unsigned int* dst_base_addr;
unsigned int* dst_addr;
unsigned int dst_offset;
上述内容并未被解释为人们可能会天真地想到，但实际上会产生以下等效结果
dst_addr = dst_base_addr + dst_offset;
补救措施当然是按照以下方式进行适当的类型转换
dst_addr = (unsigned int*)((unsigned int)dst_base_addr + (dst_offset << 2));
问题：为什么在这种情况下甚至需要正确的类型转换？
答案 0 :(得分：7)
上述内容并未被解释为人们可能会天真地想到，但实际上会产生以下等效结果
C中的指针算法（可能是C ++）是以指向的东西的大小为单位完成的。如果将n添加到jQuery(document).ready(function ($) {
$(".events_link").click(function () {
var eventname = $(this).attr('id');
var ajaxurl = "<?php echo admin_url('admin-ajax.php'); ?>";
jQuery.ajax({
type: 'POST',
url: ajaxurl,
data: {
action: "all_event",
eventname: eventname
},
success: function (response) {
$(".events-thumbs").html(response);
$('.flexslider').flexslider({
animation: "slide",
slideshow: "false",
animationLoop: true,
itemWidth: 192,
itemMargin: 9,
controlNav: true,
directionNav: false
});
}
});
});
});
，则生成的代码将添加表示n int* s所需的字节数，即如果int为32位，则可能为4 * n（大多数情况下为4个字节）理智的建筑）。
这是标准的C行为。