我是android的新手,我正在尝试使手机摄像头拍照并以图像视图显示。捕获图像后,将正确保存图像,但此后,应用程序将停止运行,此时应在图像视图中显示图像。任何帮助表示赞赏。我搜索了一些主题,但仍然无济于事。
这是代码:
package myfirstapp.myapps.me.camera;
import ...
public class MainActivity extends ActionBarActivity {
ImageButton camBtn;
ImageView imageView;
ScrollView scrollView;
private File imageFile;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void OpenCam(View view) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imageFile=new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),"image.jpg");
Uri tempURI=Uri.fromFile(imageFile);
intent.putExtra(MediaStore.EXTRA_OUTPUT, tempURI);
intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
startActivityForResult(intent, 0);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 0)//==0 the same where startActivityForResult(intent, 0) so we are in the same process
{
switch (resultCode){
case Activity.RESULT_OK:
if(imageFile.exists())
{
Toast.makeText(MainActivity.this, "Image was saved at "+imageFile.getAbsolutePath(), Toast.LENGTH_SHORT)
.show();
Bitmap myBitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
ImageView myImage = (ImageView) findViewById(R.id.imageView);
myImage.setImageBitmap(myBitmap);
}
else
{
Toast.makeText(MainActivity.this, "Image wasn't saved", Toast.LENGTH_SHORT)
.show();
}
break;
case Activity.RESULT_CANCELED:
Toast.makeText(MainActivity.this, "Image capture was cancelled", Toast.LENGTH_SHORT)
.show();
break;
}
}
}
}
堆栈跟踪
由以下原因引起:java.lang.RuntimeException:无法传递结果
ResultInfo {who = null,request = 0,result = -1,data = null}到活动
{myfirstapp.myapps.me.camera/myfirstapp.myapps.me.camera.MainActivity}:
java.lang.NullPointerException在
android.app.ActivityThread.deliverResults(ActivityThread.java:3410)在
android.app.ActivityThread.performResumeActivity(ActivityThread.java:2817)
在
android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2859)
最佳答案
请输入以下代码:
public static final int REQUEST_IMAGE_CAPTURE = 1;
public static final int RESULT_LOAD_IMAGE = 10;
private Bitmap myBitmap;
ImageView myImage ;
public void OpenCam(View view) {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null)
{
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}
并且,
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK)
{
Bundle extras = data.getExtras();
myBitmap= (Bitmap) extras.get("data");
myImage = (ImageView) findViewById(R.id.imageView);
myImage.setImageBitmap(myBitmap);
}
if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) {
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();
myBitmap= BitmapFactory.decodeFile(picturePath);
// photoUri = picturePath;
myImage.setImageBitmap(myBitmap);
}
}