[转载]Android 分享机顶盒项目的封装类《GridView》 – Terry_龙 – 博客园.
由于使用系统自带的GridView 不够灵活,不能允许拖拉控件,故自己结合LinearLayout 封装的一个GridView ,通过本篇文章的阅读你可以学会如何自定义控件,如何使用组合控件,如何为自己的组合控件添加数据源和如何为自定义控件添加属性。
首先,我们要实现的效果是这样的:
上面1 2也是一个封装控件,用来为应用程序分页,具体如何实现下篇文章会提到,本篇先讲GridView。如图,这是一个标准的800*480大小的屏幕,所以设置了一页GridView 显示的应用程序数据为 三行五列,不足五列则按需显示。
按照上面的图例需求,大致上可以把GridView 画成如下的方式:
思路如下:
默认将我们的组合控件设置为Orientation 是VERTICAL。 首先一行五个,那么一行以一个Orientation 为HORIZONTAL 的线性布局包起来。然后在一行结束后,将Orientation 的线性布局添加进组合控件里面来,不足五个则按需添加进来。
实现这一效果我们需要两个类,一个类用来表示GridView 的行,这里我们起名为TableRow,代码如下:
private TableCell[] cell; public TableRow(TableCell[] cell) {
this.cell = cell;
} public int getSize() {
return cell.length;
} public TableCell getCellValue(int index) {
if (index >= getSize()) {
return null;
}
return cell[index];
} public int getCellCount() { return cell.length;
}
public int getLastCellCount() {return lastRowCount;
}
}
另外一个类用来表示GridView 每行的列个,这里我们取名为TableCell,代码如下:
private Object value; public TableCell(Object value) {
this.value = value;
} public Object getValue() {
return value;
}
}
并且我们还需要为GridView 设置一个外部可添加数据的方法,代码如下:
this.adapter = appsAdapter;
this.setOrientation(LinearLayout.VERTICAL);
bindView();
}
其中,AppsAdapter 是一个自定义的BaseAdapter ,代码很简单,这里就不列出来了。关键的还是要看bindView ,这个方法是本篇GridView 显示数据的核心方法,代码如下:
removeAllViews();
int count = adapter.getCount();
TableCell[] cell = null;
int j = 0;
LinearLayout layout;
tableRowsList = new ArrayList<HashMap<String, Object>>();
for (int i = 0; i < count; i++) {
j++;
final int position = i;
if (j > getColumnCount() || i == 0) {
cell = new TableCell[getColumnCount()];
}
final View view
= adapter.getView(i, null, null);view.setOnTouchListener(
new OnTouchListener() {@Override
// TODO Auto-generated method stub
unCheckPressed();
checkRowID = –1;
checkColumnID = –1;
if (onItemClickEvent != null) {
onItemClickEvent.onItemClick(position,
event, view);}
return false;
}
});
view.setOnLongClickListener(
new OnLongClickListener() {@Override
if (onLongPress != null) {
onLongPress.onLongPress(v);
}
return true;
}
});
cell[j – 1] = new TableCell(view);
if (j == getColumnCount()) {
lastRowCount = j;
j = 0;
HashMap<String, Object> map = new HashMap<String, Object>();
TableRow tr = new TableRow(cell);
map.put(“tableRow“, tr);
tableRowsList.add(map);
layout = new LinearLayout(getContext());
addLayout(layout, cell, tr.getSize(), tr);
}
else if (i >= count – 1 && j > 0) {lastRowCount = j;
HashMap<String, Object> map = new HashMap<String, Object>();
TableRow tr = new TableRow(cell);
map.put(“tableRow“, tr);
tableRowsList.add(map);
layout = new LinearLayout(getContext());
addLayout(layout, cell, j, tr);
}
}
}
getColumnCount()是一个属性,表示可以从xml或者从代码动态改变GridView 每列显示的个数,属性点的代码为如下:
super(context, attrs);
int resouceID = –1;
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.GridViewExt);
int N = typedArray.getIndexCount();
for (int i = 0; i < N; i++) {
int attr = typedArray.getIndex(i);
switch (attr) {
case R.styleable.GridViewExt_ColumnCount:
resouceID = typedArray.getInt(
R.styleable.GridViewExt_ColumnCount, 0);
setColumnCount(resouceID);
break;
}
}
typedArray.recycle();
}
当然,你必须在res 创建属性xml ,这里不多讲,可以去我博客看看如何为 View 添加属性 。
还有,还必须实现它的支持键盘的上下左右的焦点,下面的代码将会提供该功能,但还必须配合Activity 的操作,等下文再讲述。效果是这样的:
该 类的全部源码为:
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import Android.content.Context;
import Android.content.Intent;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.yaomei.activity.adapter.AppsAdapter;
import com.yaomei.activity.info.R;
public List<HashMap<String, Object>> tableRowsList;
private List<HashMap<String, Object>> app = new ArrayList<HashMap<String, Object>>();
private AppsAdapter adapter;
onItemClickListener onItemClickEvent;
onLongPressExt onLongPress;
int checkColumnID = –1; // 选中列的下标
int lastRowCount = –1; // 最后一行的总数
private int ColumnCount; // 每列的总数
public void setColumnCount(int count) {
this.ColumnCount = count;
} public int getColumnCount() {
return ColumnCount;
} public interface onItemClickListener {
public boolean onItemClick(int position, MotionEvent event, View view);
} public interface onLongPressExt {
public boolean onLongPress(View view);
} public gridViewExt(Context context) {
this(context, null);
// TODO Auto-generated constructor stub
} public gridViewExt(Context context, AttributeSet attrs) {
super(context, attrs);
int resouceID = –1;
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.GridViewExt);
int N = typedArray.getIndexCount();
for (int i = 0; i < N; i++) {
int attr = typedArray.getIndex(i);
switch (attr) {
case R.styleable.GridViewExt_ColumnCount:
resouceID = typedArray.getInt(
R.styleable.GridViewExt_ColumnCount, 0);
setColumnCount(resouceID);
break;
}
}
typedArray.recycle();
}
this.onItemClickEvent = click;
} public void setOnLongPressListener(onLongPressExt longPress) {
this.onLongPress = longPress;
} public void NotifyDataChange() {
removeAllViews();
} void bindView() {
removeAllViews();
int count = adapter.getCount();
TableCell[] cell = null;
int j = 0;
LinearLayout layout;
tableRowsList = new ArrayList<HashMap<String, Object>>();
for (int i = 0; i < count; i++) {
j++;
final int position = i;
if (j > getColumnCount() || i == 0) {
cell = new TableCell[getColumnCount()];
}
final View view
= adapter.getView(i, null, null);view.setOnTouchListener(
new OnTouchListener() {@Override
// TODO Auto-generated method stub
unCheckPressed();
checkRowID = –1;
checkColumnID = –1;
if (onItemClickEvent != null) {
onItemClickEvent.onItemClick(position,
event, view);}
return false;
}
});
view.setOnLongClickListener(
new OnLongClickListener() {@Override
if (onLongPress != null) {
onLongPress.onLongPress(v);
}
return true;
}
});
cell[j – 1] = new TableCell(view);
if (j == getColumnCount()) {
lastRowCount = j;
j = 0;
HashMap<String, Object> map = new HashMap<String, Object>();
TableRow tr = new TableRow(cell);
map.put(“tableRow“, tr);
tableRowsList.add(map);
layout = new LinearLayout(getContext());
addLayout(layout, cell, tr.getSize(), tr);
}
else if (i >= count – 1 && j > 0) {lastRowCount = j;
HashMap<String, Object> map = new HashMap<String, Object>();
TableRow tr = new TableRow(cell);
map.put(“tableRow“, tr);
tableRowsList.add(map);
layout = new LinearLayout(getContext());
addLayout(layout, cell, j, tr);
}
}
}
private void addLayout(LinearLayout layout, TableCell[] cell, int size,TableRow tr) {
LinearLayout.LayoutParams
params = new LinearLayout.LayoutParams(130,110);
layout.setGravity(Gravity.LEFT);
layout.setOrientation(LinearLayout.HORIZONTAL);
View remoteView = (View) tr.getCellValue(k).getValue();
layout.addView(remoteView, k, params);
}
LinearLayout.LayoutParams firstParams = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
firstParams.leftMargin = 60;
addView(layout, firstParams);
} public void setAdapter(AppsAdapter appsAdapter) {
this.adapter = appsAdapter;
this.setOrientation(LinearLayout.VERTICAL);
bindView();
} public void checkPressed(int tableRowId, int tableRowColumnId) {
ViewGroup view = (ViewGroup) this.getChildAt(tableRowId);
checkColumnID
= tableRowColumnId;checkRowID = tableRowId;
changeImageState(view.getChildAt(tableRowColumnId), app);
}
public void onClick(int tableRowId, int tableRowColumnId, Context context) {LinearLayout view = (LinearLayout) ((ViewGroup) this
.getChildAt(tableRowId)).getChildAt(tableRowColumnId);
TextView tv
= (TextView) view.findViewById(R.id.folder);final String[] name = tv.getText().toString().split(“–“);
Intent intent = null;
if (name[0].toString().equals(“com.android.contacts“)) {
if (name[1].toString().equals(
“com.android.contacts.DialtactsActivity“)) {
intent = new Intent(Intent.ACTION_DIAL);
}
if (name[1].toString().equals(
“com.android.contacts.DialtactsContactsEntryActivity“)) {
intent = new Intent(Intent.ACTION_CALL_BUTTON);
}
} else {
intent = getContext().getPackageManager()
.getLaunchIntentForPackage(name[0].toString());
}
context.startActivity(intent);
}
/*** 改变图片状态
*
* @param v
* @param list
*/
private void changeImageState(View v, List<HashMap<String, Object>> list) {
int size = list.size();
for (int i = 0; i < size; i++) {
View view = (View) list.get(i).get(“touch“);
view.setPressed(false);
list.remove(i);
}
v.setPressed(true);
HashMap<String, Object> map = new HashMap<String, Object>();
map.put(“touch“, v);
list.add(map);
}
public void unCheckPressed() {if (checkColumnID != –1 && checkRowID != –1) {
ViewGroup view = (ViewGroup) this.getChildAt(checkRowID);
view.getChildAt(checkColumnID).setPressed(false);
}
}
private TableCell[] cell; public TableRow(TableCell[] cell) {
this.cell = cell;
} public int getSize() {
return cell.length;
} public TableCell getCellValue(int index) {
if (index >= getSize()) {
return null;
}
return cell[index];
} public int getCellCount() { return cell.length;
}
public int getLastCellCount() {return lastRowCount;
}
} static public class TableCell {
private Object value; public TableCell(Object value) {
this.value = value;
} public Object getValue() {
return value;
}
}
}
每行显示的LAYOUT文件:
android:background=”@drawable/lessbtn” android:gravity=”center”
android:layout_width=”fill_parent” android:id=”@+id/grid_layout”
android:layout_height=”fill_parent” xmlns:android=”http://schemas.android.com/apk/res/android”> <ImageView android:id=”@+id/btn_appicon”
android:layout_width=”55dip” android:layout_height=”55dip”></ImageView>
<TextView android:id=”@+id/tv_name” android:layout_width=”wrap_content”
android:textColor=”#030303″ android:layout_height=”wrap_content”></TextView>
<TextView android:id=”@+id/folder” android:layout_width=”wrap_content”
android:visibility=”invisible” android:layout_height=”wrap_content”></TextView> </LinearLayout>
完成这一系列的编写后,你就可以在xml直接写或者在JAVA文件里面new 出来,但注意要设置它每列显示的个数。
下篇将讲述如何实现手势切屏,如何实现分页显示数据,如何实现封装分页控件。