Android网格布局(GridView)---实现漂亮的多选效果

           接上文

          上一篇文章中主要讲了GridView的简单应用，以网格的形式展示了一些图片，对于图片也有点击

     监听操作。但是，如果我们在浏览图片的时候需要一些选中操作、甚至是多选操作的时候。这样的

     功能我们又该如何实现呢？

           可以使用ActionBar +GridView的形式实现！在谈及具体实现之前，首先我们先了解一下什么是

     ActionBar：

            Action Bar是活动中的一种控件，用以代替传统的品目顶端的标题栏，它提供了多便利性。有关

      其详细内容会在以后研究，现在主要考虑上述需求的实现。

                  先上效果图

           首先是关于ActionBar的布局文件：主要是用于实现全选与全不选的功能的。

         其次是其样式文件：

           字符资源文件：

    GridView
    选中%s个
    全选
    全不选

             grid_item.xml文件

                  main.xml

            actionBar_layout.xml文件：

              GridItem.java文件：

package com.kiritor;
/**
 * @author Kiritor
 * 实现自己的View继承Checable接口*/
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Checkable;
import android.widget.ImageView;
import android.widget.RelativeLayout;

public class GridItem extends RelativeLayout implements Checkable {

    private Context mContext;
    private boolean mChecked;//判断该选项是否被选上的标志量
    private ImageView mImgView = null;
    private ImageView mSecletView = null;

    public GridItem(Context context) {
        this(context, null, 0);
    }

    public GridItem(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public GridItem(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
        mContext = context;
        LayoutInflater.from(mContext).inflate(R.layout.grid_item, this);
        mImgView = (ImageView) findViewById(R.id.img_view);
        mSecletView = (ImageView) findViewById(R.id.select);
    }

    @Override
    public void setChecked(boolean checked) {
        // TODO Auto-generated method stub
        mChecked = checked;
        setBackgroundDrawable(checked ? getResources().getDrawable(
                R.drawable.background) : null);
        mSecletView.setVisibility(checked ? View.VISIBLE : View.GONE);//选上了则显示小勾图片
    }

    @Override
    public boolean isChecked() {
        // TODO Auto-generated method stub
        return mChecked;
    }

    @Override
    public void toggle() {
        setChecked(!mChecked);
    }

    public void setImgResId(int resId) {
        if (mImgView != null) {
            mImgView.setBackgroundResource(resId);//设置背景
        }
    }

}

       主activity文件：

package com.kiritor;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.ActionMode;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView.LayoutParams;
import android.widget.AbsListView.MultiChoiceModeListener;
import android.widget.BaseAdapter;
import android.widget.Checkable;
import android.widget.FrameLayout;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.TextView;

public class HomeActivity extends Activity implements MultiChoiceModeListener {

	private GridView mGridView;
	private GridAdapter mGridAdapter;
	private TextView mActionText;
	private static final int MENU_SELECT_ALL = 0;
	private static final int MENU_UNSELECT_ALL = MENU_SELECT_ALL + 1;
	private Map mSelectMap = new HashMap();

	private int[] mImgIds = new int[] { R.drawable.img_1, R.drawable.img_2,
			R.drawable.img_3, R.drawable.img_4, R.drawable.img_5,
			R.drawable.img_6, R.drawable.img_7, R.drawable.img_8,
			R.drawable.img_9, R.drawable.img_1, R.drawable.img_2,
			R.drawable.img_3, R.drawable.img_4, R.drawable.img_5,
			R.drawable.img_6, R.drawable.img_7, R.drawable.img_3,
			R.drawable.img_4, R.drawable.img_5, R.drawable.img_5 };

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		mGridView = (GridView) findViewById(R.id.gridview);
		mGridView.setChoiceMode(GridView.CHOICE_MODE_MULTIPLE_MODAL);// 设置为多选模式
		mGridAdapter = new GridAdapter(this);
		mGridView.setAdapter(mGridAdapter);// 数据适配
		mGridView.setMultiChoiceModeListener(this);// 设置多选模式监听器
	}

	/** Override MultiChoiceModeListener start **/
	@Override
	public boolean onCreateActionMode(ActionMode mode, Menu menu) {
		// TODO Auto-generated method stub
		// 得到布局文件的View
		View v = LayoutInflater.from(this).inflate(R.layout.actionbar_layout,
				null);
		mActionText = (TextView) v.findViewById(R.id.action_text);
		// 设置显示内容为GridView选中的项目个数
		mActionText.setText(formatString(mGridView.getCheckedItemCount()));
		// 设置动作条的视图
		mode.setCustomView(v);
		// 得到菜单
		getMenuInflater().inflate(R.menu.action_menu, menu);
		return true;
	}

	@Override
	public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
		// TODO Auto-generated method stub
		/* 初始状态下,如果选中的项数不等于总共的项数,设置"全选"的状态为True */
		menu.getItem(MENU_SELECT_ALL).setEnabled(
				mGridView.getCheckedItemCount() != mGridView.getCount());
		return true;
	}

	@Override
	public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
		// TODO Auto-generated method stub
		/*
		 * 当点击全选的时候,全选 点击全不选的时候全不选
		 */
		switch (item.getItemId()) {
		case R.id.menu_select:
			for (int i = 0; i < mGridView.getCount(); i++) {
				mGridView.setItemChecked(i, true);
				mSelectMap.put(i, true);
			}
			break;
		case R.id.menu_unselect:
			for (int i = 0; i < mGridView.getCount(); i++) {
				mGridView.setItemChecked(i, false);
				mSelectMap.clear();
			}
			break;
		}
		return true;
	}

	@Override
	public void onDestroyActionMode(ActionMode mode) {
		// TODO Auto-generated method stub
		mGridAdapter.notifyDataSetChanged();
	}

	@Override
	public void onItemCheckedStateChanged(ActionMode mode, int position,
			long id, boolean checked) {
		// TODO Auto-generated method stub
		// 当每个项状态改变的时候的操作
		mActionText.setText(formatString(mGridView.getCheckedItemCount()));
		mSelectMap.put(position, checked);/* 放入选中的集合中 */
		mode.invalidate();
	}

	/** Override MultiChoiceModeListener end **/

	private String formatString(int count) {
		return String.format(getString(R.string.selection), count);
	}

	private class GridAdapter extends BaseAdapter {

		private Context mContext;

		public GridAdapter(Context ctx) {
			mContext = ctx;
		}

		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return mImgIds.length;
		}

		@Override
		public Integer getItem(int position) {
			// TODO Auto-generated method stub
			return Integer.valueOf(mImgIds[position]);
		}

		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		@SuppressWarnings("deprecation")
		@Override
		/* 得到View */
		public View getView(int position, View convertView, ViewGroup parent) {
			GridItem item;
			if (convertView == null) {
				item = new GridItem(mContext);
				item.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
						LayoutParams.FILL_PARENT));
			} else {
				item = (GridItem) convertView;
			}
			item.setImgResId(getItem(position));
			item.setChecked(mSelectMap.get(position) == null ? false
					: mSelectMap.get(position));
			return item;
		}
	}

}

                 完整源码:

                       http://download.csdn.net/detail/kiritor/5144666