Android 图片裁剪功能实现详解（类似QQ自定义头像裁剪）

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