Bitmap切割，GridView显示，更新

GridView一些属性介绍

android:numColumns="auto_fit" --------每行多少个，这个是自动
android:columnWidth="20dp"，----------每列的宽度，也就是Item的宽度
android:stretchMode="columnWidth"------缩放与列宽大小同步
android:verticalSpacing="10dp"----------垂直边距
android:horizontalSpacing="10dp"-------水平边距

思路：

1，在xml文件中定义了一个Button,和一个GridView

2，在MainActivity中的Button点击事件里，点击启动线程，通过Bitmap进行分割。

3，分割完成后通过GridView添加到适配器BaseAdapter里

4，通过消息机制Handler更新UI

5，实现GridView监听方法setOnItemClickListener.实现删除

代码xml文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity" >    <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="sendBitmap"        android:text="点击切割图片" />    <GridView         android:id="@+id/main_gview"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginTop="50dp"         android:verticalSpacing="3dp"         android:horizontalSpacing="3dp"         android:numColumns="4"        />   </RelativeLayout> <span style="color:#ff0000;font-weight: bold; ">    </span>

MainActivity中代码

package com.example.bitmap;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.util.Log;import android.view.View;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.BaseAdapter;import android.widget.GridView;import android.widget.ImageView;public class MainActivity extends Activity implements OnItemClickListener {private GridView gv;// 定义集合装填图片，数据源private List<Bitmap> list;// 适配器private GridViewAdapter adapter;private Handler handle = new Handler() {public void handleMessage(Message msg) {if (msg.what == 1) {// 显示gv.setAdapter(adapter);}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);// 初始话GritViewgv = (GridView) findViewById(R.id.main_gview);// 调用适配器删除gv.setOnItemClickListener(this);}// 将图片分割并显示到页面上public void sendBitmap(View v) {new Thread() {public void run() {//声明集合装填图片，数据源list = new ArrayList<Bitmap>();//获取图片Bitmap bm = BitmapFactory.decodeResource(getResources(),R.drawable.mm);// 定义切割的宽和高int xwidth = 5;int yheight = 5;// 每份的长度 = 总长度/切割的长度int xbm = bm.getWidth() / xwidth;int ybm = bm.getHeight() / yheight;// 循环遍历for (int i = 0; i < xwidth; i++) {for (int j = 0; j < yheight; j++) {// 切割。异常原因，宽度必须小于图片的宽度// java.lang.IllegalArgumentException: x + width must be// <= bitmap.width()// 需要切割的图片资源、切割起始点的X坐标、切割起始点的Y坐标、切割多宽、切割多高。Bitmap newbm = Bitmap.createBitmap(bm, j * xbm,i * ybm, xbm, ybm);list.add(newbm);// 核心代码完毕，传参数传bm,切割高和宽}}adapter = new GridViewAdapter(list, MainActivity.this);handle.sendEmptyMessage(1);}}.start();}@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position,long id) {// 删除list.remove(list.get(position));//更新adapter.notifyDataSetChanged();}}<span style="color:#ff0000;font-weight: bold; "></span>

BaseAdapter适配器里

package com.example.bitmap;import java.util.List;import android.graphics.Bitmap;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;public class GridViewAdapter extends BaseAdapter {private List<Bitmap> datas;private MainActivity mat;public GridViewAdapter(List<Bitmap> datas, MainActivity mat) {this.datas = datas;this.mat = mat;}@Overridepublic int getCount() {// TODO Auto-generated method stubreturn datas.size();}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn datas.get(position);}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View v;ViewHolder vh;if (convertView==null) {v = mat.getLayoutInflater().inflate(R.layout.gview_main, null);vh = new ViewHolder();vh.iv = (ImageView) v.findViewById(R.id.gview_iv);v.setTag(vh);}else{v = convertView;vh = (ViewHolder) v.getTag();}//这里显示的是Bitmapvh.iv.setImageBitmap(datas.get(position));return v;}static class ViewHolder{ImageView iv;}}<span style="color:#ff0000;font-weight: bold; "></span>

子布局的xml文件

<?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="match_parent" >    <ImageView         android:id="@+id/gview_iv"        android:layout_width="wrap_content"        android:layout_height="wrap_content"                /></RelativeLayout><strong></strong>

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