android实现手机App实现拍照功能示例

 <?xml version="1.0" encoding="utf-8"?>
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/activity_takephoto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingbottom="@dimen/activity_vertical_margin"
  android:paddingleft="@dimen/activity_horizontal_margin"
  android:paddingright="@dimen/activity_horizontal_margin"
  android:paddingtop="@dimen/activity_vertical_margin"
  tools:context="com.example.android_27.takephotoactivity">
      <surfaceview
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/sv_takephoto"
        />
  <linearlayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="拍照"
      android:id="@+id/b_ok"
      />
    <button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="切换"
      android:id="@+id/b_qh"
      />
  </linearlayout>
</relativelayout>

public class takephotoactivity extends appcompatactivity {

  private surfaceview sv_takephoto;
  private button b_ok;
  private button b_qh;
  private camera camera;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_takephoto);
    //获得surfaceview的id
    sv_takephoto =(surfaceview) findviewbyid(r.id.sv_takephoto);
    //获得拍照的id
    b_ok =(button)findviewbyid(r.id.b_ok);
    //获得切换镜头的id
    b_qh =(button)findviewbyid(r.id.b_qh);

    sv_takephoto.getholder().addcallback(new surfaceholder.callback() {
      @override
      public void surfacecreated(surfaceholder surfaceholder) {
      //打开相机
        camera = camera.open();
        //给相机设置参数
        camera.parameters parameters= camera.getparameters();
        //设置保存的格式
        parameters.setpictureformat(pixelformat.jpeg);
        parameters.set("jpeg-quality",85);
        camera.setparameters(parameters);

        //将画面展示到surfaceview中
        try {
          camera.setpreviewdisplay(sv_takephoto.getholder());
          //开启预览
          camera.startpreview();
        } catch (ioexception e) {
          e.printstacktrace();
        }

      }

      @override
      public void surfacechanged(surfaceholder surfaceholder, int i, int i1, int i2) {

      }

      @override
      public void surfacedestroyed(surfaceholder surfaceholder) {

      }
    });

    //拍照的点击事件
    b_ok.setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view view) {
        //拍照
        camera.takepicture(null, null, new camera.picturecallback() {
          @override
          public void onpicturetaken(byte[] bytes, camera camera) {
            //将字节数组转成图片
            bitmap bitmap= bitmapfactory.decodebytearray(bytes,0,bytes.length);
            try {
              fileoutputstream fos=new fileoutputstream("/mnt/sdcard/dcim/"+system.currenttimemillis()+".jpg");
              bitmap.compress(bitmap.compressformat.png,85,fos);
              camera.stoppreview();
              camera.startpreview();
            } catch (filenotfoundexception e) {
              e.printstacktrace();
            }
          }
        });

    }
    });

  }
}

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