系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListVi - android

系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView, ExpandableList

作者：webabcd

介绍
在 Android 中使用各种控件(View)
TextSwitcher - 文字转换器控件（改变文字时增加一些动画效果）
Gallery - 缩略图浏览器控件
ImageSwitcher - 图片转换器控件（改变图片时增加一些动画效果）
GridView - 网格控件
ListView - 列表控件
ExpandableList - 支持展开/收缩功能的列表控件

1、TextSwitcher 的 Demo
textswitcher.xml

代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">

<Button android:id="@+id/btnChange" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="改变文字" />


<TextSwitcher android:id="@+id/textSwitcher"
android:layout_width="fill_parent" android:layout_height="wrap_content" />

</LinearLayout>

_TextSwitcher.java

代码
package com.webabcd.view;

import java.util.Random;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.TextSwitcher;
import android.widget.TextView;
import android.widget.ViewSwitcher;

public class _TextSwitcher extends Activity implements ViewSwitcher.ViewFactory {

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.setContentView(R.layout.textswithcer);

setTitle("TextSwithcer");

final TextSwitcher switcher = (TextSwitcher) findViewById(R.id.textSwitcher);
// 指定转换器的 ViewSwitcher.ViewFactory
switcher.setFactory(this);

// 设置淡入和淡出的动画效果
Animation in = AnimationUtils.loadAnimation(this, android.R.anim.fade_in);
Animation out = AnimationUtils.loadAnimation(this, android.R.anim.fade_out);
switcher.setInAnimation(in);
switcher.setOutAnimation(out);

// 单击一次按钮改变一次文字
Button btnChange = (Button) this.findViewById(R.id.btnChange);
btnChange.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
switcher.setText(String.valueOf(new Random().nextInt()));
}
});
}

// 重写 ViewSwitcher.ViewFactory 的 makeView()，返回一个 View
@Override
public View makeView() {
TextView textView = new TextView(this);
textView.setTextSize(36);
return textView;
}
}

2、Gallery 的 Demo
gallery.xml

代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">


<Gallery android:id="@+id/gallery" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:spacing="20px" />

</LinearLayout>

_Gallery.java

代码
package com.webabcd.view;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.Toast;
import android.widget.Gallery.LayoutParams;

public class _Gallery extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.setContentView(R.layout.gallery);

setTitle("Gallery");

Gallery gallery = (Gallery) findViewById(R.id.gallery);
// 为缩略图浏览器指定一个适配器
gallery.setAdapter(new ImageAdapter(this));
// 响应在缩略图列表上选中某个缩略图后的事件
gallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View v,
int position, long id) {
Toast.makeText(_Gallery.this, String.valueOf(position), Toast.LENGTH_SHORT).show();
}

@Override
public void onNothingSelected(AdapterView<?> arg0) {

}
});
}

// 继承 BaseAdapter 用以实现自定义的图片适配器
public class ImageAdapter extends BaseAdapter {

private Context mContext;

public ImageAdapter(Context context) {
mContext = context;
}

public int getCount() {
return mThumbIds.length;
}

public Object getItem(int position) {
return position;
}

public long getItemId(int position) {
return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
ImageView image = new ImageView(mContext);

image.setImageResource(mThumbIds[position]);
image.setAdjustViewBounds(true);
image.setLayoutParams(new Gallery.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

return image;
}
}

// 需要显示的图片集合
private Integer[] mThumbIds = { R.drawable.icon01, R.drawable.icon02,
R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };
}

3、ImageSwitcher 的 Demo
imageswitcher.xml

代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">

<Gallery android:id="@+id/gallery" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:spacing="20px" />


<ImageSwitcher android:id="@+id/imageSwitcher"
android:layout_width="fill_parent" android:layout_height="wrap_content" />

</LinearLayout>

_ImageSwitcher.java

代码
package com.webabcd.view;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher;
import android.widget.Gallery.LayoutParams;

// 图片转换器的使用基本同文字转换器
// 以下是一个用 ImageSwitcher + Gallery 实现的经典的图片浏览器的 Demo
public class _ImageSwitcher extends Activity implements
ViewSwitcher.ViewFactory {

private ImageSwitcher mSwitcher;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.setContentView(R.layout.imageswithcer);

setTitle("ImageSwithcer");

mSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
mSwitcher.setFactory(this);
mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_in));
mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_out));

Gallery gallery = (Gallery) findViewById(R.id.gallery);
gallery.setAdapter(new ImageAdapter(this));
gallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View v,
int position, long id) {
mSwitcher.setImageResource(mImageIds[position]);
}

@Override
public void onNothingSelected(AdapterView<?> arg0) {

}
});
}

public class ImageAdapter extends BaseAdapter {

private Context mContext;

public ImageAdapter(Context context) {
mContext = context;
}

public int getCount() {
return mThumbIds.length;
}

public Object getItem(int position) {
return position;
}

public long getItemId(int position) {
return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
ImageView image = new ImageView(mContext);

image.setImageResource(mThumbIds[position]);
image.setAdjustViewBounds(true);
image.setLayoutParams(new Gallery.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

return image;
}
}

private Integer[] mThumbIds = { R.drawable.icon01, R.drawable.icon02,
R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };

private Integer[] mImageIds = { R.drawable.icon01, R.drawable.icon02,
R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };

@Override
public View makeView() {
ImageView image = new ImageView(this);
image.setMinimumHeight(200);
image.setMinimumWidth(200);
image.setScaleType(ImageView.ScaleType.FIT_CENTER);
image.setLayoutParams(new ImageSwitcher.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
return image;
}
}

4、GridView 的 Demo
gridview.xml

代码
<?xml version="1.0" encoding="utf-8"?>


<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridView" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:padding="10px"
android:verticalSpacing="10px" android:horizontalSpacing="10px"
android:numColumns="auto_fit" android:columnWidth="60px"
android:stretchMode="columnWidth" android:gravity="center">
</GridView>

_GridView.java

代码
package com.webabcd.view;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class _GridView extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.setContentView(R.layout.gridview);

setTitle("GridView");

GridView gridView = (GridView) findViewById(R.id.gridView);
// 指定网格控件的适配器为自定义的图片适配器
gridView.setAdapter(new ImageAdapter(this));
}

// 自定义的图片适配器
public class ImageAdapter extends BaseAdapter {

private Context mContext;

public ImageAdapter(Context context) {
mContext = context;
}

public int getCount() {
return mThumbIds.length;
}

public Object getItem(int position) {
return position;
}

public long getItemId(int position) {
return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(48, 48));
imageView.setAdjustViewBounds(false);
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(5, 5, 5, 5);
} else {
imageView = (ImageView) convertView;
}

imageView.setImageResource(mThumbIds[position]);

return imageView;
}

// 网格控件所需图片数据的数据源
private Integer[] mThumbIds = { R.drawable.icon01, R.drawable.icon02,
R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };
}
}

5、ListView 的 Demo
main_list_adapter.xml

代码
<?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/text" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:textSize="16sp">
</TextView>

</LinearLayout>

MainListAdapter.java

代码
package com.webabcd.view;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

// 继承 BaseAdapter 以实现自定义的列表适配器
public class MainListAdapter extends BaseAdapter {

private LayoutInflater mInflater;
private List<String> mData;

public MainListAdapter(Context context, List<String> data) {
mInflater = LayoutInflater.from(context);
mData = data;
}

@Override
public int getCount() {
return mData.size();
}

@Override
public Object getItem(int position) {
return mData.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

TextView text;

if (convertView == null) {
// 指定一个 layout 作为自定义列表适配器的 layout
convertView = mInflater.inflate(R.layout.main_list_adapter, null);
text = (TextView) convertView.findViewById(R.id.text);
convertView.setTag(text);
} else {
text = (TextView) convertView.getTag();
}

String mItem = mData.get(position);
text.setText(mItem);

return convertView;
}
}

Main.java

代码
package com.webabcd.view;

import java.util.ArrayList;
import java.util.List;

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;

// 此处要继承 ListActivity ，用以实现 ListView 的功能
public class Main extends ListActivity {

private List<String> mData;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setTheme(android.R.style.Theme_Light);
setContentView(R.layout.main);
mData = getData();

// 使用自定义的列表适配器来展现数据
MainListAdapter adapter = new MainListAdapter(this, mData);

// 如需使用系统内置的列表适配器，则可以使用类似如下的方法
// ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1, mData);

this.setListAdapter(adapter);
}

// ListView 的数据源
private List<String> getData() {
List<String> items = new ArrayList<String>();

items.add("TextView");
items.add("Button");
items.add("ImageButton");
items.add("ImageView");
items.add("CheckBox");
items.add("RadioButton");
items.add("AnalogClock");
items.add("DigitalClock");
items.add("DatePicker");
items.add("TimePicker");
items.add("ToggleButton");
items.add("EditText");
items.add("ProgressBar");
items.add("SeekBar");
items.add("AutoCompleteTextView");
items.add("MultiAutoCompleteTextView");
items.add("ZoomControls");
items.add("Include");
items.add("VideoView");
items.add("WebView");
items.add("RatingBar");
items.add("Tab");
items.add("Spinner");
items.add("Chronometer");
items.add("ScrollView");
items.add("TextSwitcher");
items.add("ListView");
items.add("Gallery");
items.add("ImageSwitcher");
items.add("GridView");
items.add("ExpandableList");

return items;
}

// ListView 中某项被选中后的逻辑
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Intent intent = new Intent();
intent.setClassName(this, "com.webabcd.view._" + mData.get(position));

startActivityForResult(intent, 0);
}
}

6、ExpandableList 的 Demo
_ExpandableList.java

代码
package com.webabcd.view;

import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ExpandableListView.ExpandableListContextMenuInfo;

// ExpandableList - 可展开/收缩列表
// 继承 ExpandableListActivity 以实现列表的可展开/收缩的功能
public class _ExpandableList extends ExpandableListActivity {

private ExpandableListAdapter mAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

setTitle("ExpandableList");

mAdapter = new MyExpandableListAdapter();
setListAdapter(mAdapter);
registerForContextMenu(this.getExpandableListView());
}

// 为列表的每一项创建上下文菜单（即长按后呼出的菜单）
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
menu.setHeaderTitle("ContextMenu");
menu.add(0, 0, 0, "ContextMenu");
}

// 单击上下文菜单后的逻辑
@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 + " - Group Index: " + groupPos + " Child Index: " + childPos, 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 Index: " + groupPos, Toast.LENGTH_SHORT).show();

return true;
}

return false;
}

public class MyExpandableListAdapter extends BaseExpandableListAdapter {

// 父列表数据
private String[] groups =
{
"group1",
"group2",
"group3",
"group4"
};
// 子列表数据
private String[][] children =
{
{ "child1" },
{ "child1", "child2" },
{ "child1", "child2", "child3" },
{ "child1", "child2", "child3", "child4" }
};

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

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

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

// 取子列表中的某一项的 View
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
TextView textView = getGenericView();
textView.setText(getChild(groupPosition, childPosition).toString());
return textView;
}

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

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

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

// 取父列表中的某一项的 View
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
TextView textView = getGenericView();
textView.setText(getGroup(groupPosition).toString());
return textView;
}

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

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

// 获取某一项的 View 的逻辑
private TextView getGenericView() {
AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, 48);
TextView textView = new TextView(_ExpandableList.this);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
textView.setPadding(32, 0, 0, 0);
return textView;
}
}
}

系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListVi

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