《Android开发卷——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