遍历指定目录下的图片文件 显示在gridview

<?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:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center"
/>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/root"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
>
<ImageView
android:id="@+id/image"
android:layout_width="100dp"
android:layout_height="150dp"
android:layout_gravity="center"
android:scaleType="fitXY"
android:padding="4dp"
/>
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center_horizontal"
/>
</LinearLayout>

package com.su.testgrid3;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.GridView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class TestGrid3Activity extends Activity {
private GridView gridView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

String[] titles = FileUtil.getImageNames("/mnt/sdcard/k/");
String[] imagePaths = new String[titles.length];
for (int i = 0; i < titles.length; i++) {
imagePaths[i]="/mnt/sdcard/k/"+titles[i];
}

gridView = (GridView) findViewById(R.id.gridview);
PictureAdapter adapter = new PictureAdapter(titles, imagePaths, this);
gridView.setAdapter(adapter);

gridView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
Toast.makeText(TestGrid3Activity.this, "你点击了" + (position + 1),
Toast.LENGTH_SHORT).show();
}
});

gridView.setOnItemLongClickListener(new OnItemLongClickListener(){
public boolean onItemLongClick(AdapterView<?> parent, View v,
int position, long id) {
Toast.makeText(TestGrid3Activity.this, "你长按了" + (position + 1),
Toast.LENGTH_SHORT).show();
return true;
/*
* 这里需要true
* 因为:OnItemLongClick事件中：down事件返回值标记此次事
* 件是否为点击事件（返回false，是点击事件；返回true，不记为点击事件），
* 而up事件标记此次事件结束时间，也就是判断是否为长按。
*/

}

});
}
}

// 2012-4-18下午07:46:57

package com.su.testgrid3;

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

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

//自定义适配器
class PictureAdapter extends BaseAdapter {
private LayoutInflater inflater;
private List<Picture> pictures;

public PictureAdapter(String[] titles, String[] images, Context context) {
super();
pictures = new ArrayList<Picture>();
inflater = LayoutInflater.from(context);
for (int i = 0; i < images.length; i++) {
Picture picture = new Picture(titles[i], images[i]);
pictures.add(picture);
}
}

@Override
public int getCount() {
if (null != pictures) {
return pictures.size();
} else {
return 0;
}
}

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

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.picture_item, null);
viewHolder = new ViewHolder();
viewHolder.title = (TextView) convertView.findViewById(R.id.title);
viewHolder.image = (ImageView) convertView.findViewById(R.id.image);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.title.setText(pictures.get(position).getTitle());
viewHolder.image.setImageBitmap(BitmapFactory.decodeFile(pictures.get(
position).getImageId()));
return convertView;
}

}

class ViewHolder {
public TextView title;
public ImageView image;
}

// 2012-4-18下午07:47:44

package com.su.testgrid3;

class Picture {
private String title;
private String imageId;

public Picture() {
super();
}

public Picture(String title, String imageId) {
super();
this.title = title;
this.imageId = imageId;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public String getImageId() {
return imageId;
}

public void setImageId(String imageId) {
this.imageId = imageId;
}
}

// 2012-4-18下午07:49:44

package com.su.testgrid3;

import java.io.File;

public class FileUtil {
public static String[] getImageNames(String folderPath) {
File file01 = new File(folderPath);

String[] files01 = file01.list();

int imageFileNums = 0;
for (int i = 0; i < files01.length; i++) {
File file02 = new File(folderPath + "/" + files01[i]);

if (!file02.isDirectory()) {

if (isImageFile(file02.getName())) {

imageFileNums++;
}
}
}

String[] files02 = new String[imageFileNums];

int j = 0;
for (int i = 0; i < files01.length; i++) {
File file02 = new File(folderPath + "/" + files01[i]);

if (!file02.isDirectory()) {

if (isImageFile(file02.getName())) {
files02[j] = file02.getName();
j++;
}
}
}
return files02;
}

private static boolean isImageFile(String fileName) {
String fileEnd = fileName.substring(fileName.lastIndexOf(".") + 1,
fileName.length());
if (fileEnd.equalsIgnoreCase("jpg")) {
return true;
} else if (fileEnd.equalsIgnoreCase("png")) {
return true;
} else if (fileEnd.equalsIgnoreCase("bmp")) {
return true;
} else {
return false;
}
}

}