由于我刚入职现在的这家公司的时候，他们对涉及到图片的比较多，所以打算写一系列图片的文章，首先就从制造图片的地方开始写起--Camera如果你的app里面只是需要拍一张照片，只需要调用系统的照相机就可以满足你的需求了通过ACTION_IMAGE_CAPTURE调用系统的照相机
intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
然后在通过startActivityForResult方法跳转onActivityResult：
Bundle extras = data.getExtras();
Bitmap bitmap = (Bitmap) extras.get("data");
showImage.setImageBitmap(bitmap);
一般的情况下这样就满足了你的需求，也不需要增加权限，但是这里需要注意的是通过data获得的是一张缩略图，如果想获得一张原图，就需要指定图片的保存地址
Uri uri = Uri.fromFile(new File(path)); intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE); intent.putExtra(MediaStore.EXTRA_OUTPUT,uri);
同样使用startActivityForResult方法跳转onActivityResult：
FileInputStream fileInputStream = null;
Bitmap output;
try {
int degree = PhotoUtil.readPictureDegree(path);
fileInputStream = new FileInputStream(new File(path));
output = BitmapFactory.decodeStream(fileInputStream);
showImage.setImageBitmap(
PhotoUtil.rotaingImageView(degree,output));
} catch (FileNotFoundException e) {
e.printStackTrace();
}finally {
if (fileInputStream != null){
try { fileInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
其实拿到这个需要一下两句话就能拿到这个bitmap
fileInputStream = new FileInputStream(new File(path));
output = BitmapFactory.decodeStream(fileInputStream);
但是保存在本地的图片，直接这样取得的照片旋转了90度，其中图片的旋转角度是记录在exif中的，所以为了把图片旋转过来，索性直接利用exif去取角度
public static int readPictureDegree(String path) {
int degree = 0;
try {
ExifInterface exifInterface = new ExifInterface(path);
int orientation = exifInterface.getAttributeInt( ExifInterface.TAG_ORIENTATION,ExifInterface.ORIENTATION_NORMAL);
switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_90:
degree = 90;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
degree = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_270:
degree = 270;
break;
}
} catch (IOException e) {
e.printStackTrace();
}
return degree;
}
然后根据取到的角度旋转bitmap
public static Bitmap rotaingImageView(int angle , Bitmap bitmap) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
return resizedBitmap;
}
对于图片的操作后面再说这样就能实现获得原图，并且能够正向的显示图片，但是很多app不只是拍一张照片而已，所以下面开始介绍自定义Camera
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
private Camera camera;
private SurfaceHolder holder;
private Context context;
private String picUrl;
public CameraView(Context context) {
super(context);
this.context = context;
initHolder();
}
public CameraView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
initHolder();
}
public CameraView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.context = context;
initHolder();
}
private void initHolder() {
holder = this.getHolder(); holder.addCallback(this);
}
private boolean existCamera(Context context) {
return context.getPackageManager().
hasSystemFeature(PackageManager.FEATURE_CAMERA);
}
private void initCamera() {
if (camera == null) {
camera = Camera.open();
}
}
private void imagePreview(SurfaceHolder holder) {
try {
if (camera != null) {
camera.setPreviewDisplay(holder);
camera.setDisplayOrientation(90);
camera.startPreview();
}
} catch (IOException e) {
e.printStackTrace();
}
}
private void setParameters() {
if (camera != null) {
Camera.Parameters parameters =
camera.getParameters();
parameters.setPictureFormat(ImageFormat.JPEG);
parameters.setRotation(90);
parameters.setFlashMode(
Camera.Parameters.FLASH_MODE_AUTO);
camera.setParameters(parameters);
}
}
private void releaseCamera() {
if (camera != null) {
camera.setPreviewCallback(null);
camera.stopPreview();
camera.release();
camera = null;
}
}
public void autoFocus(){
if (camera != null){
camera.autoFocus(new Camera.AutoFocusCallback() {
@Override
public void onAutoFocus(boolean success, Camera camera) {
if (success){
takePicture();
}
}
}); }
}
public void takePicture(){
if (camera != null){
camera.takePicture(null, null, new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
if (picUrl == null) {
picUrl = Environment.getExternalStorageDirectory() + File.separator + "zimo.jpg";
}
File file = new File(picUrl);
if (file.exists()) {
file.delete();
}
try {
FileOutputStream fos = new FileOutputStream(file);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
imagePreview(holder);
}
});
}}
@Override
public void surfaceCreated(SurfaceHolder holder) {
if (existCamera(context)){
initCamera();
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
setParameters();
imagePreview(holder);
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
releaseCamera();
}
public void setPicUrl(String picUrl) {
this.picUrl = picUrl;
}
上面是一个自定义的Camera，继承了SurfaceView 1. 检查Camera是否存在 2. 初始化Camera 3. 设置参数 4. 预览图片 5. 拍照 6. 释放Camera这就是自定义Camera实现的步骤了，当然还有增加权限
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
只要把CameraView当成自定义控件使用就好
<com.zimo.guo.customcamera.view.CameraView
android:id="@+id/camera"
android:layout_width="match_parent"
android:layout_height="match_parent" />
点击拍照按钮直接调用takePicture()，当然也可以自己定义图片地址
cameraView.setPicUrl(path);
cameraView.takePicture();
还可以实现聚焦之后自动拍照
cameraView.autoFocus();
下篇开始研究图片了，这篇就先到这！
