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 - 文字转换器控件(改变文字时增加一些动画效果)
-->
<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 - 缩略图浏览器控件
spacing - 缩略图列表中各个缩略图之间的间距
-->
<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 - 图片转换器控件(改变图片时增加一些动画效果)
-->
<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 - 网格控件
numColumns="auto_fit" - 列数自适应
stretchMode - 缩放模式(stretchMode="columnWidth" - 缩放与列宽大小同步)
-->
<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"?>
<!--
自定义列表适配器的 layout
-->
<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>