使用摄像头Api在android中打开摄像头
我已经尝试了所有现有的方法。。但每次应用程序关闭时。这是代码。请帮我调试一下 MainActivity.java使用摄像头Api在android中打开摄像头,android,camera,Android,Camera,我已经尝试了所有现有的方法。。但每次应用程序关闭时。这是代码。请帮我调试一下 MainActivity.java package com.example.camera1; import android.os.Bundle; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.hardware.Camera; import android.hardware.Camera.Pict
package com.example.camera1;
import android.os.Bundle;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
private Camera cameraObject;
private ShowCamera showCamera;
private ImageView pic;
public static Camera isCameraAvailiable(){
Camera object = null;
try { object = Camera.open();
} catch (Exception e){
} return object;
}
private PictureCallback capturedIt = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data , 0, data .length);
if(bitmap==null){
Toast.makeText(getApplicationContext(), "not taken", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(getApplicationContext(), "taken", Toast.LENGTH_SHORT).show();
}
cameraObject.release();
}
};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pic = (ImageView)findViewById(R.id.imageView1);
cameraObject = isCameraAvailiable();
showCamera = new ShowCamera(this, cameraObject);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(showCamera);
}
public void snapIt(View view){
cameraObject.takePicture(null, null, capturedIt);
}
@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;
}
}
ShowCamera.java
package com.example.camera1;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class ShowCamera extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder holdMe;
private Camera theCamera;
public ShowCamera(Context context,Camera camera) {
super(context);
theCamera = camera;
holdMe = getHolder();
holdMe.addCallback(this);
// TODO Auto-generated constructor stub
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
try {
theCamera.setPreviewDisplay(holder);
theCamera.startPreview();
} catch (IOException e)
{
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}
activity_main.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" >
<FrameLayout
android:id="@+id/camera_preview"
android:layout_width="fill_parent"
android:layout_height="199dp" >
</FrameLayout>
<Button
android:id="@+id/button_capture"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick = "snapIt"
android:text="@string/Capture"/>
<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="fitXY"
android:src="@drawable/ic_launcher"/>
</LinearLayout>
我是为android姜饼和以上版本制作的。我的目标sdk是Android Kitkat。
在姜饼上测试应用程序时,它会打开应用程序,但只会显示一个白色屏幕,即它不会加载布局并强制关闭。。请帮忙 要打开相机,请适当使用以下代码:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
Camera.CameraInfo info=new Camera.CameraInfo();
for (int i=0; i < Camera.getNumberOfCameras(); i++) {
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
camera=Camera.open(i);
}
}
}
if (camera == null) {
camera=Camera.open();
}
您可以保留Camera.Parameters对象,并通过在surfaceChanged中放置复选框将参数设置为该值
<>你也可以考虑在一个单独的线程中启动你的相机,就像在这里所做的:
//This code is from AOSP ICS:
Thread mCameraOpenThread = new Thread(new Runnable() {
public void run() {
try {
mCameraDevice = Util.openCamera(Camera.this, mCameraId);
} catch (CameraHardwareException e) {
mOpenCameraFail = true;
} catch (CameraDisabledException e) {
mCameraDisabled = true;
}
}
});
这是onCreate方法:
super.onCreate(icicle);
mCameraOpenThread.start();
SurfaceView preview = (SurfaceView) findViewById(R.id.camera_preview);
SurfaceHolder holder = preview.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// Make sure camera device is opened.
try {
mCameraOpenThread.join();
mCameraOpenThread = null;
}
catch(InterruptedException e)
{
//ignore
}
代码链接在这里当应用程序强制关闭时,它会将异常放入eclipse中的“logcat”窗口中。请记住,一旦摄像头应用程序崩溃,它可能无法正确释放摄像头,因此,即使您的代码在下一轮中是正确的,在您的摄像头正确释放之前,它也无法正常工作。请放弃主要活动的onCreate方法
super.onCreate(icicle);
mCameraOpenThread.start();
SurfaceView preview = (SurfaceView) findViewById(R.id.camera_preview);
SurfaceHolder holder = preview.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// Make sure camera device is opened.
try {
mCameraOpenThread.join();
mCameraOpenThread = null;
}
catch(InterruptedException e)
{
//ignore
}