android自定义Camera拍照并查看图片

本文实例为大家分享了android自定义camera拍照并查看图片的具体代码，供大家参考，具体内容如下

1、打开相机

a.预览拍摄图片，需用到surfaceview，并且实现其回调函数implements surfaceholder.callback；
activity_camera.xml

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical" >

  <surfaceview
    android:id="@+id/sv"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1" />

  <button
    android:id="@+id/btn_camera"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="拍照" />

</linearlayout>

2、获取相机并开启预览

/**
   * 获取系统相机
   * 
   * @return
   */
  private camera getccamera() {
    camera camera = null;
    try {
      camera = camera.open();
    } catch (exception e) {
      camera = null;
    }
    return camera;
  }

/**
   * 显示相机预览图片
   * 
   * @return
   */
  private void showcameraview(camera camera,surfaceholder holder)
  {
    try {
      camera.setpreviewdisplay(holder);
      camera.setdisplayorientation(90);
      camera.startpreview();
    }catch (exception e){
      e.printstacktrace();
    };

  }

/**
** 实现界面回调处理
*/
  @override
  public void surfacecreated(surfaceholder holder) {
    showcameraview(mcamera, holder);
  }

  @override
  public void surfacechanged(surfaceholder holder, int format, int width, int height) {
    mcamera.stoppreview();
    showcameraview(mcamera, holder);
  }

  @override
  public void surfacedestroyed(surfaceholder holder) {
    clearcamera();
  }
}

3、相机主页面处理

public class cameraactivity extends appcompatactivity implements surfaceholder.callback{

  private surfaceview sv;
  private camera mcamera;
  private surfaceholder holder;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_camera);
    sv = (surfaceview)findviewbyid(r.id.sv);
    holder = sv.getholder();
    holder.addcallback(this);

    findviewbyid(r.id.btn_camera).setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view v) {
        // 获取当前相机参数
        camera.parameters parameters = mcamera.getparameters();
        // 设置相片格式
        parameters.setpictureformat(imageformat.jpeg);
        // 设置预览大小
        parameters.setpreviewsize(800, 480);
        // 设置对焦方式，这里设置自动对焦
        parameters.setfocusmode(camera.parameters.focus_mode_auto);
        mcamera.autofocus(new camera.autofocuscallback() {

          @override
          public void onautofocus(boolean success, camera camera) {
            // 判断是否对焦成功
            if (success) {
              // 拍照 第三个参数为拍照回调
              mcamera.takepicture(null, null, new camera.picturecallback() {
                @override
                public void onpicturetaken(byte[] data, camera camera) {
                  // data为完整数据
                  file file = new file("/sdcard/photo.png");
                  // 使用流进行读写
                  try {
                    fileoutputstream fos = new fileoutputstream(file);
                    try {
                      fos.write(data);
                      // 关闭流
                      fos.close();
                      // 查看图片
                      intent intent = new intent();
                      // 传递路径
                      intent.putextra("path", file.getabsolutepath());
                      setresult(0,intent);
                      finish();
                    } catch (ioexception e) {
                      // todo auto-generated catch block
                      e.printstacktrace();
                    }
                  } catch (filenotfoundexception e) {
                    // todo auto-generated catch block
                    e.printstacktrace();
                  }
                }
              });
            }
          }
        });
      }
    });

  }

 @override
  protected void onresume() {
    super.onresume();
    if (mcamera == null) {
      mcamera = getcamera();
      if (holder != null) {
        showcameraview(mcamera, holder);
      }
    }
  }
  @override
  protected void onpause() {
    // todo auto-generated method stub
    super.onpause();
    // activity暂停时我们释放相机内存
    clearcamera();

  }
  @override
  protected void ondestroy() {
    super.ondestroy();
  }

  /**
   * 释放相机的内存
   */
  private void clearcamera() {

    // 释放hold资源
    if (mcamera != null) {
      // 停止预览
      mcamera.stoppreview();
      mcamera.setpreviewcallback(null);
      // 释放相机资源
      mcamera.release();
      mcamera = null;
    }
  }

4、启动activity（设置拍照完图片路径返回显示图片处理，一定要对图片进行采样率操作（很可能拍照的图片太多而无法显示，又不报任何异常））

public class mainactivity extends appcompatactivity {

  private imageview cameraiv;

  @override
  protected void onactivityresult(int requestcode, int resultcode, intent data) {
    if(resultcode == 0 && requestcode == 100)
    {
      string path = data.getstringextra("path");
      bitmapfactory.options options = new bitmapfactory.options();
      options.injustdecodebounds = true;
      bitmapfactory.decodefile(path, options);
      imagesize imagesize = getimageviewsize(cameraiv);
      options.insamplesize = caculateinsamplesize(options,
          imagesize.width, imagesize.height);

      // 使用获得到的insamplesize再次解析图片
      options.injustdecodebounds = false;
      bitmap bitmap = bitmapfactory.decodefile(path, options);
      cameraiv.setimagebitmap(bitmap);
    }

    super.onactivityresult(requestcode, resultcode, data);
  }

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);

    button openbutton = (button) findviewbyid(r.id.button);
    cameraiv = (imageview) findviewbyid(r.id.imageview);



    openbutton.setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view v) {
        intent intent = new intent(mainactivity.this,cameraactivity.class);
        startactivityforresult(intent,100);
      }
    });
  }

   /* 根据需求的宽和高以及图片实际的宽和高计算samplesize
   *
       * @param options
   * @param width
   * @param height
   * @return
       */
  public static int caculateinsamplesize(bitmapfactory.options options, int reqwidth,
                      int reqheight)
  {
    int width = options.outwidth;
    int height = options.outheight;

    int insamplesize = 1;

    if (width > reqwidth || height > reqheight)
    {
      int widthradio = math.round(width * 1.0f / reqwidth);
      int heightradio = math.round(height * 1.0f / reqheight);

      insamplesize = math.max(widthradio, heightradio);
    }

    return insamplesize;
  }

  public static imagesize getimageviewsize(imageview imageview)
  {

    imagesize imagesize = new imagesize();
    displaymetrics displaymetrics = imageview.getcontext().getresources()
        .getdisplaymetrics();

    linearlayout.layoutparams lp = (linearlayout.layoutparams)imageview.getlayoutparams();

    int width = imageview.getwidth();// 获取imageview的实际宽度
    if (width <= 0)
    {
      width = lp.width;// 获取imageview在layout中声明的宽度
    }

    if (width <= 0)
    {
      width = displaymetrics.widthpixels;
    }

    int height = imageview.getheight();// 获取imageview的实际高度
    if (height <= 0)
    {
      height = lp.height;// 获取imageview在layout中声明的宽度
    }

    if (height <= 0)
    {
      height = displaymetrics.heightpixels;
    }
    imagesize.width = width;
    imagesize.height = height;

    return imagesize;
  }

  public static class imagesize
  {
    int width;
    int height;
  }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。