Android：设置圆形头像，Android截取圆形图片

在有一些程序开发中,有时候会用到圆形,截取一张图片的一部分圆形,作为头像或者其他.

本实例就是截图圆形,设置头像的.

  

 

首先讲解一些代码

 <ImageView android:id="@+id/screenshot_img"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="matrix"/>

图片属性要设置成android:scaleType="matrix",这样图片才可以通过触摸,放大缩小.

主类功能:点击按钮选择图片或者拍照

 public class MainActivity extends Activity {

     private Button btnImg;

     /**
      * 表示选择的是相机--0
      */
     private final int IMAGE_CAPTURE = 0;
     /**
      * 表示选择的是相册--1
      */
     private final int IMAGE_MEDIA = 1;

     /**
      * 图片保存SD卡位置
      */
     private final static String IMG_PATH = Environment
             .getExternalStorageDirectory() + "/chillax/imgs/";

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);

         btnImg = (Button)findViewById(R.id.btn_find_img);
         btnImg.setOnClickListener(BtnClick);
     }

     OnClickListener BtnClick = new OnClickListener() {
         @Override
         public void onClick(View v) {
             // TODO Auto-generated method stub
             setImage();
         }
     };

     /**
      * 选择图片
      */
     public void setImage() {
         final AlertDialog.Builder builder = new AlertDialog.Builder(this);
         builder.setTitle("选择图片");
         builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
             @Override
             public void onClick(DialogInterface dialog, int which) {}
         });
         builder.setPositiveButton("相机", new DialogInterface.OnClickListener() {
             @Override
             public void onClick(DialogInterface dialog, int which) {
                 Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                 startActivityForResult(intent, IMAGE_CAPTURE);
             }
         });
         builder.setNeutralButton("相册", new DialogInterface.OnClickListener() {
             @Override
             public void onClick(DialogInterface dialog, int which) {
                 Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                 intent.setType("image/*");
                 startActivityForResult(intent, IMAGE_MEDIA);
             }
         });
         AlertDialog alert = builder.create();
         alert.show();
     }

     /**
      * 根据用户选择,返回图片资源
      */
     public void onActivityResult(int requestCode, int resultCode, Intent data) {

         ContentResolver resolver = this.getContentResolver();

         BitmapFactory.Options options = new BitmapFactory.Options();
         options.inSampleSize = 2;// 图片高宽度都为本来的二分之一，即图片大小为本来的大小的四分之一
         options.inTempStorage = new byte[5 * 1024];

         if (data != null){
             if (requestCode == IMAGE_MEDIA){
                 try {
                     if(data.getData() == null){
                     }else{

                         // 获得图片的uri
                         Uri uri = data.getData();

                         // 将字节数组转换为ImageView可调用的Bitmap对象
                         Bitmap bitmap = BitmapFactory.decodeStream(
                                 resolver.openInputStream(uri), null,options);

                         //图片路径
                         String imgPath = IMG_PATH+"Test.png";

                         //保存图片
                         saveFile(bitmap, imgPath);

                         Intent i = new Intent(MainActivity.this,ScreenshotImg.class);
                         i.putExtra("ImgPath", imgPath);
                         this.startActivity(i);

                     }
                 } catch (Exception e) {
                     System.out.println(e.getMessage());
                 }

             }else if(requestCode == IMAGE_CAPTURE) {// 相机
                 if (data != null) {
                     if(data.getExtras() == null){
                     }else{

                         // 相机返回的图片数据
                         Bitmap bitmap = (Bitmap) data.getExtras().get("data");

                         //图片路径
                         String imgPath = IMG_PATH+"Test.png";

                         //保存图片
                         saveFile(bitmap, imgPath);

                         Intent i = new Intent(MainActivity.this,ScreenshotImg.class);
                         i.putExtra("ImgPath", imgPath);
                         this.startActivity(i);
                     }
                 }
             }
         }
     }

     /**
      * 保存图片到app指定路径
      * @param bm头像图片资源
      * @param fileName保存名称
      */
     public static void saveFile(Bitmap bm, String filePath) {
             try {
                 String Path = filePath.substring(0, filePath.lastIndexOf("/"));
                 File dirFile = new File(Path);
                 if (!dirFile.exists()) {
                     dirFile.mkdirs();
                 }
                 File myCaptureFile = new File(filePath);
                 BufferedOutputStream bo = null;
                 bo = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
                 bm.compress(Bitmap.CompressFormat.PNG, 100, bo);

                 bo.flush();
                 bo.close();

             } catch (FileNotFoundException e) {
                 e.printStackTrace();
             } catch (IOException e) {
                 e.printStackTrace();
             }
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
         getMenuInflater().inflate(R.menu.main, menu);
         return true;
     }

 }

注意:有时候要对图片进行压缩,不然在程序中很容易就造成内存溢出.

BitmapFactory.Options options = new BitmapFactory.Options();

options.inSampleSize = 2;// 图片高宽度都为本来的二分之一

options.inTempStorage = new byte[5 * 1024];

// 获得图片的uri

Uri uri = data.getData();

// 将字节数组转换为ImageView可调用的Bitmap对象
Bitmap bitmap = BitmapFactory.decodeStream(resolver.openInputStream(uri), null,options);

图片缩放,截图类:

 public class ScreenshotImg extends Activity {

     private LinearLayout imgSave;
     private ImageView imgView,imgScreenshot;
     private String imgPath;

     private static final int NONE = 0;
     private static final int DRAG = 1;
     private static final int ZOOM = 2;

     private int mode = NONE;
     private float oldDist;
     private Matrix matrix = new Matrix();
     private Matrix savedMatrix = new Matrix();
     private PointF start = new PointF();
     private PointF mid = new PointF();

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         // TODO Auto-generated method stub
         super.onCreate(savedInstanceState);
         this.setContentView(R.layout.img_screenshot);

         imgView = (ImageView)findViewById(R.id.screenshot_img);
         imgScreenshot = (ImageView)findViewById(R.id.screenshot);
         imgSave = (LinearLayout)findViewById(R.id.img_save);

         Intent i = getIntent();
         imgPath = i.getStringExtra("ImgPath");

         Bitmap bitmap = getImgSource(imgPath);

         if(bitmap!=null){
             imgView.setImageBitmap(bitmap);
             imgView.setOnTouchListener(touch);
             imgSave.setOnClickListener(imgClick);
         }

     }

     OnClickListener imgClick = new OnClickListener() {
         @Override
         public void onClick(View v) {
             // TODO Auto-generated method stub
             imgView.setDrawingCacheEnabled(true);
             Bitmap bitmap = Bitmap.createBitmap(imgView.getDrawingCache());

             int w = imgScreenshot.getWidth();
             int h = imgScreenshot.getHeight();

             int left = imgScreenshot.getLeft();
             int right = imgScreenshot.getRight();
             int top = imgScreenshot.getTop();
             int bottom = imgScreenshot.getBottom();

             Bitmap targetBitmap = Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888);

             Canvas canvas = new Canvas(targetBitmap);
             Path path = new Path();

             path.addCircle((float)((right-left) / 2),((float)((bottom-top)) / 2), (float)(w / 2),
             Path.Direction.CCW);

             canvas.clipPath(path);

             canvas.drawBitmap(bitmap,new Rect(left,top,right,bottom),new Rect(left,top,right,bottom),null);

             MainActivity.saveFile(targetBitmap, imgPath);

             Toast.makeText(getBaseContext(), "保存成功", Toast.LENGTH_LONG).show();

             finish();
         }
     };

     /**
      * 触摸事件
      */
     OnTouchListener touch = new OnTouchListener() {
         @Override
         public boolean onTouch(View v, MotionEvent event) {
             ImageView view = (ImageView) v;
             switch (event.getAction() & MotionEvent.ACTION_MASK) {
             case MotionEvent.ACTION_DOWN:
                 savedMatrix.set(matrix); // 把原始 Matrix对象保存起来
                 start.set(event.getX(), event.getY()); // 设置x,y坐标
                 mode = DRAG;
                 break;
             case MotionEvent.ACTION_UP:
             case MotionEvent.ACTION_POINTER_UP:
                 mode = NONE;
                 break;
             case MotionEvent.ACTION_POINTER_DOWN:
                 oldDist = spacing(event);
                 if (oldDist > 10f) {
                     savedMatrix.set(matrix);
                     midPoint(mid, event); // 求出手指两点的中点
                     mode = ZOOM;
                 }
                 break;
             case MotionEvent.ACTION_MOVE:
                 if (mode == DRAG) {
                     matrix.set(savedMatrix);

                     matrix.postTranslate(event.getX() - start.x, event.getY()
                             - start.y);
                 } else if (mode == ZOOM) {
                     float newDist = spacing(event);
                     if (newDist > 10f) {
                         matrix.set(savedMatrix);
                         float scale = newDist / oldDist;
                         matrix.postScale(scale, scale, mid.x, mid.y);
                     }
                 }
                 break;
             }
             System.out.println(event.getAction());
             view.setImageMatrix(matrix);
             return true;
         }
     };

     //求两点距离
     private float spacing(MotionEvent event) {
     float x = event.getX(0) - event.getX(1);
     float y = event.getY(0) - event.getY(1);
     return FloatMath.sqrt(x * x + y * y);
     }

     //求两点间中点
     private void midPoint(PointF point, MotionEvent event) {
     float x = event.getX(0) + event.getX(1);
     float y = event.getY(0) + event.getY(1);
     point.set(x / 2, y / 2);
     }

     /**
      * 從指定路徑讀取圖片資源
      */
     public Bitmap getImgSource(String pathString) {

         Bitmap bitmap = null;
         BitmapFactory.Options opts = new BitmapFactory.Options();
 //      opts.inSampleSize = 2;

         try {
             File file = new File(pathString);
             if (file.exists()) {
                 bitmap = BitmapFactory.decodeFile(pathString, opts);
             }
             if (bitmap == null) {
                 return null;
             } else {
                 return bitmap;
             }
         } catch (Exception e) {
             e.printStackTrace();
             return null;
         }
     }

 }

截图关键语句:

Bitmap targetBitmap = Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888);
               
 Canvas canvas = new Canvas(targetBitmap);
Path path = new Path();
       
path.addCircle((float)((right-left) / 2),((float)((bottom-top)) / 2), (float)(w / 2),
Path.Direction.CCW);     //绘制圆形
       
canvas.clipPath(path);
       
canvas.drawBitmap(bitmap,new Rect(left,top,right,bottom),new Rect(left,top,right,bottom),null);    //截图

项目源码:http://download.csdn.net/detail/chillax_li/7120673

(有人说保存图片之后,没打开图片.这是因为我没打开它,要看效果的话,要自己用图库打开,就能看到效果了.这里说明一下)

尊重原创,转载请注明出处:http://blog.csdn.net/chillax_li/article/details/22591681