在项目中经常需要选择手机系统里面的图片，但是直接启动系统页面，只能选择单张图片，而且UI不受我们自己控制，不灵活，所以这里仿照微信的大致效果，做一个图片选择器
加载图片的时候，使用的开源项目Universal-Image-Loader，示例代码如下：
MyApplication类：
package com.home.imgscan;
import android.app.Application;
import android.content.Context;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
public class MyApplication extends Application {
@Override
public void onCreate() {
super.onCreate();
initImageLoader(this,false);
}
/**
* 初始化ImageLoader(在Application的onCreate()中调用)
*
* @param context
* 上下文对象
* @param isDebug
* 是否启用Debug模式
*/
public static void initImageLoader(Context context, boolean isDebug) {
// 创建默认的ImageLoader配置参数
ImageLoaderConfiguration.Builder builder = new ImageLoaderConfiguration.Builder(
context);
if (isDebug) {
builder.writeDebugLogs();
}
ImageLoaderConfiguration configuration = builder.build();
ImageLoader.getInstance().init(configuration);
}
}主页面：MainActivity：
package com.home.imgscan;
import java.util.ArrayList;
import java.util.List;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.GridView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
// GridView控件
private GridView gridView;
// 进度对话框
private ProgressDialog mProgressDialog;
// 本地图片路径集合
private List<String> list = new ArrayList<String>();
// 加载完成标示
private final static int SCAN_OK = 1;
// 适配器
private ScanAdapter adapter;
// 发送按钮
private TextView sendView;
@SuppressLint("HandlerLeak")
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case SCAN_OK:
mProgressDialog.dismiss();
setAdapter();
break;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
initView();
getImages();
}
/**
* 初始化页面控件
*/
private void initView() {
gridView = (GridView) findViewById(R.id.main_grid);
// 发送按钮
sendView = (TextView) findViewById(R.id.main_btn_send);
sendView.setOnClickListener(this);
}
/**
* 设置适配器
*/
private void setAdapter() {
if (adapter == null) {
adapter = new ScanAdapter(MainActivity.this, list);
gridView.setAdapter(adapter);
} else {
adapter.setList(list);
adapter.notifyDataSetChanged();
}
}
/**
* 获取手机上的图片
*/
private void getImages() {
if (!Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
Toast.makeText(this, "SD卡不存在", Toast.LENGTH_SHORT).show();
return;
}
mProgressDialog = ProgressDialog.show(this, null, "正在加载请稍后...");
new Thread(new Runnable() {
@Override
public void run() {
Uri mImageUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
ContentResolver mContentResolver = MainActivity.this
.getContentResolver();
Cursor mCursor = mContentResolver.query(mImageUri, null,
MediaStore.Images.Media.MIME_TYPE + "=? or "
+ MediaStore.Images.Media.MIME_TYPE + "=?",
new String[] { "image/jpeg", "image/png" },
MediaStore.Images.Media.DATE_MODIFIED);
while (mCursor.moveToNext()) {
String path = mCursor.getString(mCursor
.getColumnIndex(MediaStore.Images.Media.DATA));
list.add(path);
}
mCursor.close();
mHandler.sendEmptyMessage(SCAN_OK);
}
}).start();
}
/**
* 更新发送按钮
*/
public void updateSendBtn() {
List<String> hasCheckedList = adapter.getHasCheckList();
if (hasCheckedList == null || hasCheckedList.size() == 0) {
sendView.setText("发送");
} else {
int size = hasCheckedList.size();
sendView.setText("发送(" + size + "/9)");
}
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.main_btn_send) {
List<String> hasCheckedList = adapter.getHasCheckList();
if (hasCheckedList == null || hasCheckedList.size() == 0) {
Toast.makeText(this, "请选择图片", Toast.LENGTH_SHORT).show();
return;
}
// 发送。。。
}
}
}
自定义适配器ScanAdapter：
package com.home.imgscan;
import java.util.ArrayList;
import java.util.List;
import android.graphics.Bitmap;
import android.text.TextUtils;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.Toast;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.download.ImageDownloader.Scheme;
public class ScanAdapter extends BaseAdapter {
private List<String> list;
private LayoutInflater inflater;
// 已经选择的图片本地路径集合
private List<String> hasCheckList = new ArrayList<String>();
private MainActivity activity;
public ScanAdapter(MainActivity activity, List<String> list) {
this.list = list;
this.activity = activity;
inflater = LayoutInflater.from(activity);
}
@Override
public int getCount() {
return list == null ? 0 : list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup arg2) {
if (convertView == null) {
convertView = inflater.inflate(R.layout.grid_content, null);
}
String path = list.get(position);
// 选择框
ImageView box = getAdapterView(convertView, R.id.grid_content_box, path);
box.setOnClickListener(new MyOnClickListener());
// 图片控件
ImageView iv = getAdapterView(convertView, R.id.grid_content_iv, path);
setLocalImg(iv, path);
return convertView;
}
private class MyOnClickListener implements OnClickListener {
@Override
public void onClick(View v) {
if (v.getId() != R.id.grid_content_box) {
return;
}
String path = (String) v.getTag();
if (TextUtils.isEmpty(path)) {
return;
}
if (hasCheckList.contains(path)) {
hasCheckList.remove(path);
v.setBackgroundResource(R.drawable.box_unchecked);
} else {
if (hasCheckList.size() >= 9) {
Toast.makeText(activity, "最多只能选择9张图片", Toast.LENGTH_SHORT)
.show();
return;
}
hasCheckList.add(path);
v.setBackgroundResource(R.drawable.box_checked);
}
activity.updateSendBtn();
}
}
@SuppressWarnings("unchecked")
public <T extends View> T getAdapterView(View convertView, int id,
Object tag) {
SparseArray<View> viewHolder = null;
try {
if (convertView.getTag(R.id.view_holder) instanceof SparseArray<?>) {
viewHolder = (SparseArray<View>) convertView
.getTag(R.id.view_holder);
}
} catch (ClassCastException e) {
}
if (viewHolder == null) {
viewHolder = new SparseArray<View>();
convertView.setTag(R.id.view_holder, viewHolder);
convertView.setTag(R.id.path, tag);
}
View childView = viewHolder.get(id);
if (childView == null) {
childView = convertView.findViewById(id);
childView.setTag(tag);
viewHolder.put(id, childView);
}
return (T) childView;
}
/**
* 加载本地图片
*
* @param imageView
* 图片ImageView控件
* @param imagePath
* 图片本地路径
*/
public static void setLocalImg(ImageView imageView, String imagePath) {
// 显示图片的配置
DisplayImageOptions.Builder builder = new DisplayImageOptions.Builder();
builder.cacheInMemory(true).cacheOnDisk(true)
.bitmapConfig(Bitmap.Config.RGB_565);
DisplayImageOptions options = builder.build();
ImageLoader.getInstance().displayImage(Scheme.FILE.wrap(imagePath),
imageView, options);
}
public List<String> getList() {
return list;
}
public void setList(List<String> list) {
this.list = list;
}
public List<String> getHasCheckList() {
return hasCheckList;
}
public void setHasCheckList(List<String> hasCheckList) {
this.hasCheckList = hasCheckList;
}
}
布局文件main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/background_dark" >
<ImageView
android:id="@+id/main_iv_back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_margin="10dp"
android:background="@drawable/back" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="图片"
android:textColor="@android:color/white"
android:textSize="20sp" />
<TextView
android:id="@+id/main_btn_send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginTop="10dp"
android:background="@android:color/holo_green_light"
android:padding="10dp"
android:text="发送"
android:textColor="@android:color/white"
android:textSize="18sp" />
</RelativeLayout>
<GridView
android:id="@+id/main_grid"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:cacheColorHint="@android:color/transparent"
android:gravity="center"
android:horizontalSpacing="1dp"
android:listSelector="@android:color/transparent"
android:numColumns="3"
android:scrollbars="none"
android:stretchMode="columnWidth"
android:verticalSpacing="1dp" >
</GridView>
</LinearLayout>
布局文件grid_content.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/black" >
<ImageView
android:id="@+id/grid_content_iv"
android:layout_width="match_parent"
android:layout_height="100dp"
android:scaleType="centerCrop" />
<ImageView
android:id="@+id/grid_content_box"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginRight="6dp"
android:layout_marginTop="6dp"
android:background="@drawable/box_unchecked" />
</RelativeLayout>示例下载链接：http://download.csdn.net/detail/u010142437/8854871版权声明：本文为博主原创文章，未经博主允许不得转载。