相机的简单使用

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button button;
    private Button button2;
    private ImageView imageView;
    private String sdpath;
    private String picpath;
    private static int SLT=1;//请求缩略图的标识
    private static int YT=2;//请求原图的标识


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sdpath= Environment.getExternalStorageDirectory().getPath();
        picpath= sdpath+"/"+"temp.png";

        initView();


    }

    private void initView() {
        button = (Button) findViewById(R.id.button);
        button2 = (Button) findViewById(R.id.button2);
        imageView = (ImageView) findViewById(R.id.imageView);

        button.setOnClickListener(this);
        button2.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button:
//              Intent intent=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                Intent intent = new Intent(Intent.ACTION_PICK, null);
                intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
                startActivityForResult(intent,YT);
                break;
            case R.id.button2:
                Intent intent2=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                //定义一个路径
                Uri uri=Uri.fromFile(new File(picpath));
                //为拍照指定一个路径
                intent2.putExtra(MediaStore.EXTRA_OUTPUT,uri);
                startActivityForResult(intent2,YT);

                break;
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode==RESULT_OK){
            if (requestCode==SLT){
                //通过Bundle 取图片
                Bundle extras = data.getExtras();
                Bitmap bitmap = (Bitmap) extras.get("data");
                imageView.setImageBitmap(bitmap);
            }else if (requestCode==YT){
                FileInputStream fileInputStream=null;
                try {
                    fileInputStream=new FileInputStream(picpath);
                    //把流转化为BITMAP
                    Bitmap bitmap= BitmapFactory.decodeStream(fileInputStream);
                    imageView.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }finally {
                    try {
                        fileInputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }

    }
}

记住添加权限

<uses-permission android:name="android.permission.CAMERA"></uses-permission>