最近有看到有朋友在讨论QQ头像的裁剪上传是怎么实现的，吼吼，小马也没做过，好奇之下学习下，发现以前项目中有类型的功能，结合官方文档里面的解释，就更好玩了，周末，急急忙忙写的，记录在博客里，希望能与大家交流学习，也恳请高手能解答小马在代码注释中提出的疑问，不管有没有人回答，小马先谢谢了，一样的，先看下效果图（效果图小马不解释了，直接流水写下去，小马是直接在模拟器里写的，能在真机上使用，因为很简单），再看代码是怎么实现的：
一：主布局界面
二：点击控件触发事件后效果图
三：拍照完之后效果图
四：裁剪界面效果图
五：点击相册后返回的图片效果图
六：裁剪完从相册PICK的保存后的效果图
下面直接来看下主控制类代码，如下：
package com.xiaoma.piccut.demo; import java.io.File; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.net.Uri; import android.os.Bundle; import android.os.Environment; import android.provider.MediaStore; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ImageButton; import android.widget.ImageView; /** * @Title: PicCutDemoActivity.java * @Package com.xiaoma.piccut.demo * @Description: 图片裁剪功能测试 * @author XiaoMa */ public class PicCutDemoActivity extends Activity implements OnClickListener { private ImageButton ib = null; private ImageView iv = null; private Button btn = null; private String tp = null; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //初始化 init(); } /** * 初始化方法实现 */ private void init() { ib = (ImageButton) findViewById(R.id.imageButton1); iv = (ImageView) findViewById(R.id.imageView1); btn = (Button) findViewById(R.id.button1); ib.setOnClickListener(this); iv.setOnClickListener(this); btn.setOnClickListener(this); } /** * 控件点击事件实现 * * 因为有朋友问不同控件的背景图裁剪怎么实现， * 我就在这个地方用了三个控件，只为了自己记录学习 * 大家觉得没用的可以跳过啦 */ @Override public void onClick(View v) { switch (v.getId()) { case R.id.imageButton1: ShowPickDialog(); break; case R.id.imageView1: ShowPickDialog(); break; case R.id.button1: ShowPickDialog(); break; default: break; } } /** * 选择提示对话框 */ private void ShowPickDialog() { new AlertDialog.Builder(this) .setTitle("设置头像...") .setNegativeButton("相册", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); /** * 刚开始，我自己也不知道ACTION_PICK是干嘛的，后来直接看Intent源码， * 可以发现里面很多东西，Intent是个很强大的东西，大家一定仔细阅读下 */ Intent intent = new Intent(Intent.ACTION_PICK, null); /** * 下面这句话，与其它方式写是一样的效果，如果： * intent.setData(MediaStore.Images.Media.EXTERNAL_CONTENT_URI); * intent.setType(""image/*");设置数据类型 * 如果朋友们要限制上传到服务器的图片类型时可以直接写如："image/jpeg 、 image/png等的类型" * 这个地方小马有个疑问，希望高手解答下：就是这个数据URI与类型为什么要分两种形式来写呀？有什么区别？ */ intent.setDataAndType( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*"); startActivityForResult(intent, 1); } }) .setPositiveButton("拍照", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { dialog.dismiss(); /** * 下面这句还是老样子，调用快速拍照功能，至于为什么叫快速拍照，大家可以参考如下官方 * 文档，you_sdk_path/docs/guide/topics/media/camera.html * 我刚看的时候因为太长就认真看，其实是错的，这个里面有用的太多了，所以大家不要认为 * 官方文档太长了就不看了，其实是错的，这个地方小马也错了，必须改正 */ Intent intent = new Intent( MediaStore.ACTION_IMAGE_CAPTURE); //下面这句指定调用相机拍照后的照片存储的路径 intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri .fromFile(new File(Environment .getExternalStorageDirectory(), "xiaoma.jpg"))); startActivityForResult(intent, 2); } }).show(); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { // 如果是直接从相册获取 case 1: startPhotoZoom(data.getData()); break; // 如果是调用相机拍照时 case 2: File temp = new File(Environment.getExternalStorageDirectory() + "/xiaoma.jpg"); startPhotoZoom(Uri.fromFile(temp)); break; // 取得裁剪后的图片 case 3: /** * 非空判断大家一定要验证，如果不验证的话， * 在剪裁之后如果发现不满意，要重新裁剪，丢弃 * 当前功能时，会报NullException，小马只 * 在这个地方加下，大家可以根据不同情况在合适的 * 地方做判断处理类似情况 * */ if(data != null){ setPicToView(data); } break; default: break; } super.onActivityResult(requestCode, resultCode, data); } /** * 裁剪图片方法实现 * @param uri */ public void startPhotoZoom(Uri uri) { /* * 至于下面这个Intent的ACTION是怎么知道的，大家可以看下自己路径下的如下网页 * yourself_sdk_path/docs/reference/android/content/Intent.html * 直接在里面Ctrl+F搜：CROP ，之前小马没仔细看过，其实安卓系统早已经有自带图片裁剪功能, * 是直接调本地库的，小马不懂C C++ 这个不做详细了解去了，有轮子就用轮子，不再研究轮子是怎么 * 制做的了...吼吼 */ Intent intent = new Intent("com.android.camera.action.CROP"); intent.setDataAndType(uri, "image/*"); //下面这个crop=true是设置在开启的Intent中设置显示的VIEW可裁剪 intent.putExtra("crop", "true"); // aspectX aspectY 是宽高的比例 intent.putExtra("aspectX", 1); intent.putExtra("aspectY", 1); // outputX outputY 是裁剪图片宽高 intent.putExtra("outputX", 150); intent.putExtra("outputY", 150); intent.putExtra("return-data", true); startActivityForResult(intent, 3); } /** * 保存裁剪之后的图片数据 * @param picdata */ private void setPicToView(Intent picdata) { Bundle extras = picdata.getExtras(); if (extras != null) { Bitmap photo = extras.getParcelable("data"); Drawable drawable = new BitmapDrawable(photo); /** * 下面注释的方法是将裁剪之后的图片以Base64Coder的字符方式上 * 传到服务器，QQ头像上传采用的方法跟这个类似 */ /*ByteArrayOutputStream stream = new ByteArrayOutputStream(); photo.compress(Bitmap.CompressFormat.JPEG, 60, stream); byte[] b = stream.toByteArray(); // 将图片流以字符串形式存储下来 tp = new String(Base64Coder.encodeLines(b)); 这个地方大家可以写下给服务器上传图片的实现，直接把tp直接上传就可以了， 服务器处理的方法是服务器那边的事了，吼吼 如果下载到的服务器的数据还是以Base64Coder的形式的话，可以用以下方式转换 为我们可以用的图片类型就OK啦...吼吼 Bitmap dBitmap = BitmapFactory.decodeFile(tp); Drawable drawable = new BitmapDrawable(dBitmap); */ ib.setBackgroundDrawable(drawable); iv.setBackgroundDrawable(drawable); } } } 下面来看下裁剪中用到的类，大家详细看下头注释：
package com.xiaoma.piccut.demo; /** * 下面这些注释是下载这个类的时候本来就有的，本来要删除的，但看了下竟然是license，吼吼， * 好东西，留在注释里，以备不时之用，大家有需要加license的可以到下面的网址找哦 */ //EPL, Eclipse Public License, V1.0 or later, http://www.eclipse.org/legal //LGPL, GNU Lesser General Public License, V2.1 or later, http://www.gnu.org/licenses/lgpl.html //GPL, GNU General Public License, V2 or later, http://www.gnu.org/licenses/gpl.html //AL, Apache License, V2.0 or later, http://www.apache.org/licenses //BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php /** * A Base64 encoder/decoder. * * <p> * This class is used to encode and decode data in Base64 format as described in RFC 1521. * * <p> * Project home page: <a href="http://www.source-code.biz/base64coder/java/">www.source-code.biz/base64coder/java</a><br> * Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland<br> * Multi-licensed: EPL / LGPL / GPL / AL / BSD. */ /** * 这个类在上面注释的网址中有，大家可以自行下载下，也可以直接用这个， * 公开的Base64Coder类（不用深究它是怎么实现的， * 还是那句话，有轮子直接用轮子），好用的要死人了... * 小马也很无耻的引用了这个网址下的东东，吼吼... * @Title: Base64Coder.java * @Package com.xiaoma.piccut.demo * @Description: TODO * @author XiaoMa */ public class Base64Coder { //The line separator string of the operating system. private static final String systemLineSeparator = System.getProperty("line.separator"); //Mapping table from 6-bit nibbles to Base64 characters. private static char[] map1 = new char[64]; static { int i=0; for (char c='A'; c<='Z'; c++) map1[i++] = c; for (char c='a'; c<='z'; c++) map1[i++] = c; for (char c='0'; c<='9'; c++) map1[i++] = c; map1[i++] = '+'; map1[i++] = '/'; } //Mapping table from Base64 characters to 6-bit nibbles. private static byte[] map2 = new byte[128]; static { for (int i=0; i<map2.length; i++) map2[i] = -1; for (int i=0; i<64; i++) map2[map1[i]] = (byte)i; } /** * Encodes a string into Base64 format. * No blanks or line breaks are inserted. * @param s A String to be encoded. * @return A String containing the Base64 encoded data. */ public static String encodeString (String s) { return new String(encode(s.getBytes())); } /** * Encodes a byte array into Base 64 format and breaks the output into lines of 76 characters. * This method is compatible with <code>sun.misc.BASE64Encoder.encodeBuffer(byte[])</code>. * @param in An array containing the data bytes to be encoded. * @return A String containing the Base64 encoded data, broken into lines. */ public static String encodeLines (byte[] in) { return encodeLines(in, 0, in.length, 76, systemLineSeparator); } /** * Encodes a byte array into Base 64 format and breaks the output into lines. * @param in An array containing the data bytes to be encoded. * @param iOff Offset of the first byte in <code>in</code> to be processed. * @param iLen Number of bytes to be processed in <code>in</code>, starting at <code>iOff</code>. * @param lineLen Line length for the output data. Should be a multiple of 4. * @param lineSeparator The line separator to be used to separate the output lines. * @return A String containing the Base64 encoded data, broken into lines. */ public static String encodeLines (byte[] in, int iOff, int iLen, int lineLen, String lineSeparator) { int blockLen = (lineLen*3) / 4; if (blockLen <= 0) throw new IllegalArgumentException(); int lines = (iLen+blockLen-1) / blockLen; int bufLen = ((iLen+2)/3)*4 + lines*lineSeparator.length(); StringBuilder buf = new StringBuilder(bufLen); int ip = 0; while (ip < iLen) { int l = Math.min(iLen-ip, blockLen); buf.append (encode(in, iOff+ip, l)); buf.append (lineSeparator); ip += l; } return buf.toString(); } /** * Encodes a byte array into Base64 format. * No blanks or line breaks are inserted in the output. * @param in An array containing the data bytes to be encoded. * @return A character array containing the Base64 encoded data. */ public static char[] encode (byte[] in) { return encode(in, 0, in.length); } /** * Encodes a byte array into Base64 format. * No blanks or line breaks are inserted in the output. * @param in An array containing the data bytes to be encoded. * @param iLen Number of bytes to process in <code>in</code>. * @return A character array containing the Base64 encoded data. */ public static char[] encode (byte[] in, int iLen) { return encode(in, 0, iLen); } /** * Encodes a byte array into Base64 format. * No blanks or line breaks are inserted in the output. * @param in An array containing the data bytes to be encoded. * @param iOff Offset of the first byte in <code>in</code> to be processed. * @param iLen Number of bytes to process in <code>in</code>, starting at <code>iOff</code>. * @return A character array containing the Base64 encoded data. */ public static char[] encode (byte[] in, int iOff, int iLen) { int oDataLen = (iLen*4+2)/3; // output length without padding int oLen = ((iLen+2)/3)*4; // output length including padding char[] out = new char[oLen]; int ip = iOff; int iEnd = iOff + iLen; int op = 0; while (ip < iEnd) { int i0 = in[ip++] & 0xff; int i1 = ip < iEnd ? in[ip++] & 0xff : 0; int i2 = ip < iEnd ? in[ip++] & 0xff : 0; int o0 = i0 >>> 2; int o1 = ((i0 & 3) << 4) | (i1 >>> 4); int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6); int o3 = i2 & 0x3F; out[op++] = map1[o0]; out[op++] = map1[o1]; out[op] = op < oDataLen ? map1[o2] : '='; op++; out[op] = op < oDataLen ? map1[o3] : '='; op++; } return out; } /** * Decodes a string from Base64 format. * No blanks or line breaks are allowed within the Base64 encoded input data. * @param s A Base64 String to be decoded. * @return A String containing the decoded data. * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */ public static String decodeString (String s) { return new String(decode(s)); } /** * Decodes a byte array from Base64 format and ignores line separators, tabs and blanks. * CR, LF, Tab and Space characters are ignored in the input data. * This method is compatible with <code>sun.misc.BASE64Decoder.decodeBuffer(String)</code>. * @param s A Base64 String to be decoded. * @return An array containing the decoded data bytes. * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */ public static byte[] decodeLines (String s) { char[] buf = new char[s.length()+3]; int p = 0; for (int ip = 0; ip < s.length(); ip++) { char c = s.charAt(ip); if (c != ' ' && c != '\r' && c != '\n' && c != '\t') buf[p++] = c; } while ((p % 4) != 0) buf[p++] = '0'; return decode(buf, 0, p); } /** * Decodes a byte array from Base64 format. * No blanks or line breaks are allowed within the Base64 encoded input data. * @param s A Base64 String to be decoded. * @return An array containing the decoded data bytes. * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */ public static byte[] decode (String s) { return decode(s.toCharArray()); } /** * Decodes a byte array from Base64 format. * No blanks or line breaks are allowed within the Base64 encoded input data. * @param in A character array containing the Base64 encoded data. * @return An array containing the decoded data bytes. * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */ public static byte[] decode (char[] in) { return decode(in, 0, in.length); } /** * Decodes a byte array from Base64 format. * No blanks or line breaks are allowed within the Base64 encoded input data. * @param in A character array containing the Base64 encoded data. * @param iOff Offset of the first character in <code>in</code> to be processed. * @param iLen Number of characters to process in <code>in</code>, starting at <code>iOff</code>. * @return An array containing the decoded data bytes. * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */ public static byte[] decode (char[] in, int iOff, int iLen) { if (iLen%4 != 0) throw new IllegalArgumentException ("Length of Base64 encoded input string is not a multiple of 4."); while (iLen > 0 && in[iOff+iLen-1] == '=') iLen--; int oLen = (iLen*3) / 4; byte[] out = new byte[oLen]; int ip = iOff; int iEnd = iOff + iLen; int op = 0; while (ip < iEnd) { int i0 = in[ip++]; int i1 = in[ip++]; int i2 = ip < iEnd ? in[ip++] : 'A'; int i3 = ip < iEnd ? in[ip++] : 'A'; if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127) throw new IllegalArgumentException ("Illegal character in Base64 encoded data."); int b0 = map2[i0]; int b1 = map2[i1]; int b2 = map2[i2]; int b3 = map2[i3]; if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0) throw new IllegalArgumentException ("Illegal character in Base64 encoded data."); int o0 = ( b0 <<2) | (b1>>>4); int o1 = ((b1 & 0xf)<<4) | (b2>>>2); int o2 = ((b2 & 3)<<6) | b3; out[op++] = (byte)o0; if (op<oLen) out[op++] = (byte)o1; if (op<oLen) out[op++] = (byte)o2; } return out; } //Dummy constructor. private Base64Coder() {} } // end class Base64Coder 最后，小马还把小DEMO源码放在附件里面，有需要的朋友可以下载下来，共同交流学习，也恳请高人回答下小马在文章注释中提出的问题，谢谢，文章是小马急急忙忙在家写的，在网吧发的，晕...不是我有多用功，这边下雨，讨厌下雨，下雨我就郁闷，来网吧玩的，顺带发下文章，吼吼，该玩的时候死命的玩，该工作的时候死命的工作，年轻时疯狂，老了不后悔，吼吼，加油加油！大家工作，也注意身体健康，嘿嘿，你懂的，不解释...哈哈