我一直在努力让我的Galaxy Nexus上的LED手电筒亮相,在StackOverflow上使用了几种不同的解决方案:
LED flashlight on Galaxy Nexus controllable by what API?
Opening Flashlight of Galaxy Nexus
但是我仍然遇到这个错误,我看不出原因:
相机:应用程序传递NULL表面
这是我的代码(或者稍微编辑了其他解决方案的代码):
package com.quinny898.doorcontrol;
import java.io.IOException;
import android.app.Activity;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
public class DoorControlDoing extends Activity implements Callback {
public Camera mCamera;
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.dialog_surface);
SurfaceView preview = (SurfaceView) findViewById(R.id.surface_view);
SurfaceHolder mHolder = preview.getHolder();
mHolder.addCallback(this);
super.onCreate(savedInstanceState);
setContentView(R.layout.dialog_surface);
Camera mCamera = Camera.open();
Parameters params = mCamera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_TORCH);
mCamera.setParameters(params);
mCamera.startPreview();
try {
mCamera.setPreviewDisplay(mHolder);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {}
public void surfaceCreated(SurfaceHolder holder) {
setContentView(R.layout.dialog_surface);
SurfaceView preview = (SurfaceView) findViewById(R.id.surface_view);
SurfaceHolder mHolder = preview.getHolder();
mHolder = holder;
try {
mCamera.setPreviewDisplay(mHolder);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
setContentView(R.layout.dialog_surface);
SurfaceView preview = (SurfaceView) findViewById(R.id.surface_view);
SurfaceHolder mHolder = preview.getHolder();
mCamera.stopPreview();
mHolder = null;
}
}
这是布局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/surface_view"
android:layout_width="1px"
android:layout_height="1px"/>
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="@string/hi"/>
</LinearLayout>
我看不出这里有什么问题,所有的ID都是正确的,并且它的布局很好,所以为什么它是“NULL”?
感谢您的帮助!
答案 0 :(得分:0)
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
camera.setPreviewDisplay(holder);
} catch (Exception e) {
e.printStackTrace();
}
}
camera is
camera=Camera.open();