如何在android中显示最后一次从相机捕获的图像?
我正在onActivityResult中使用以下代码,但它不起作用如何在android中显示最后一次从相机捕获的图像?,android,android-camera,android-imageview,Android,Android Camera,Android Imageview,我正在onActivityResult中使用以下代码,但它不起作用 File file1 = new File( Environment.getExternalStorageDirectory().getAbsolutePath(),imagecapture); if (file1.exists()) { //Do action image=(ImageView)findViewById(R.id.image)
File file1 = new File( Environment.getExternalStorageDirectory().getAbsolutePath(),imagecapture);
if (file1.exists()) {
//Do action
image=(ImageView)findViewById(R.id.image);
Bitmap myBitmap = BitmapFactory.decodeFile(file1.getAbsolutePath());
image.setImageBitmap(myBitmap);
image.invalidate();
}
但我不明白为什么我也用过它不起作用
但是它在mimageri=Uri.fromFile(照片)一行给出了错误代码>
任何帮助都将不胜感激。上述代码中没有错误,但图像也没有显示,但当我在oncreate中使用它时,它正在工作,但我希望它在oncreate中工作onActivityResult@Shrikant你能给我一些指导或者其他的提示我怎样才能达到sameI所想的解决方案。。。你检查过文件1是否真的存在吗?是的,我已经调试过了。如果语句我无法获取哪个类的对象是fileroot,而sdImageMainDirectory是File类对象,那么必须调试你的应用程序并在onActivityResult处设置断点。检查你的onActivityResult是否得到调用如果发生这种情况,那么你的从camera activity返回后将重新创建活动,因为camera activity返回我们在ActivityResult上获得的结果。这一行文件=root.listFiles();nullpointerexception我想你应该给我文件的声明,这意味着文件对象中没有保存在路径指定的图像没有错误,但有时它会显示,但有时它不会显示图像,这真的很奇怪,我想它会给你内存不足的问题,因为图像大小太大了你有解决方案吗应该提出另一个问题:必须使用BitmapFactory压缩图像大小。选项=新建BitmapFactory.Options();option.inSampleSize=2;bm=BitmapFactory.decodeFile(root.getPath()+“/”+imageName,选项);
File root=new File(Environment.getExternalStorageDirectory()
+ File.separator + "MYPICS" + File.separator);
File sdImageMainDirectory ;
if (!root.exists()) {
root.mkdirs();
}
ImageButton cam =(ImageButton)findViewById(R.id.ImageButton1);
cam.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
imageName = "MyPic" + i + ".png";
sdImageMainDirectory = new File(root, imageName);
Uri imgUri = Uri.fromFile(sdImageMainDirectory);
Intent intent = new Intent(
android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, imgUri);
startActivityForResult(intent, 0);
}
});
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (resultCode) {
case 0:
// finish();
break;
case -1:
files = root.listFiles();
count = files.length;
try {
BitmapFactory.Options option = new BitmapFactory.Options();
option.inSampleSize = 2;
bm = BitmapFactory.decodeFile(root.getPath()+"/"+imageName,option);
ImageView imageview =(ImageView)findViewById(R.id.imageView1);
imageview .setImageBitmap(bm);
}
} catch (Exception e) {
e.printStackTrace();
}
}
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
Button btnTakePhoto;
ImageView imgTakenPhoto;
private static final int CAM_REQUREST = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btnTakePhoto = (Button) findViewById(R.id.button1);
imgTakenPhoto = (ImageView) findViewById(R.id.imageView1);
btnTakePhoto.setOnClickListener(new btnTakePhotoClicker());
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_PIC_REQUEST) {
Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
imgTakenPhoto.setImageBitmap(thumbnail);
}
}
class btnTakePhotoClicker implements Button.OnClickListener
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_PIC_REQUEST);
}
}
}