拍摄照片，然后在ImageView中加载并不总是正常工作

Question

我使用的代码来自示例here。

我的问题是，有时图像不加载到ImageView。我刚刚注意到了这种行为。我发现如果通过代码进行调试，它可以在100％的时间内正常工作。

我的假设是，图像文件有时不会及时创建，以便在onActivityResult中可用。有没有人遇到过这个问题？如何补偿的建议？

Answer 1

可能是移动处理速度问题！不能确切地说，但我试过这种方式，它总是像魅力一样工作！

public class LaunchCamera extends Activity { 
ImageView imVCature_pic; 
Button btnCapture; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_launch_camera); 
    initializeControls(); 
} 

private void initializeControls() { 
    imVCature_pic=(ImageView)findViewById(R.id.imVCature_pic); 
    btnCapture=(Button)findViewById(R.id.btnCapture); 
    btnCapture.setOnClickListener(new OnClickListener() { 

    @Override 
    public void onClick(View v) { 
    /* create an instance of intent 
    * pass action android.media.action.IMAGE_CAPTURE 
    * as argument to launch camera 
    */ 
    Intent intent = new Intent("android.media.action.IMAGE_CAPTURE"); 
    /*create instance of File with name img.jpg*/ 
    File file = new File(Environment.getExternalStorageDirectory()+File.separator + "img.jpg"); 
    /*put uri as extra in intent object*/ 
    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file)); 
    /*start activity for result pass intent as argument and request code */ 
    startActivityForResult(intent, 1); 
    } 
    }); 

} 

@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    //if request code is same we pass as argument in startActivityForResult 
    if(requestCode==1){ 
    //create instance of File with same name we created before to get image from storage 
    File file = new File(Environment.getExternalStorageDirectory()+File.separator + "img.jpg"); 
    //get bitmap from path with size of 
    imVCature_pic.setImageBitmap(decodeSampledBitmapFromFile(file.getAbsolutePath(), 600, 450)); 
    } 
} 
public static Bitmap decodeSampledBitmapFromFile(String path, 
    int reqWidth, int reqHeight) { 
    // First decode with inJustDecodeBounds=true to check dimensions 
    final BitmapFactory.Options options = new BitmapFactory.Options(); 
    //Query bitmap without allocating memory 
    options.inJustDecodeBounds = true; 
    //decode file from path 
    BitmapFactory.decodeFile(path, options); 
    // Calculate inSampleSize 
    // Raw height and width of image 
    final int height = options.outHeight; 
    final int width = options.outWidth; 
    //decode according to configuration or according best match 
    options.inPreferredConfig = Bitmap.Config.RGB_565; 
    int inSampleSize = 1; 
    if (height > reqHeight) { 
    inSampleSize = Math.round((float)height/(float)reqHeight); 
    } 
    int expectedWidth = width/inSampleSize; 
    if (expectedWidth > reqWidth) { 
    //if(Math.round((float)width/(float)reqWidth) > inSampleSize) // If bigger SampSize.. 
    inSampleSize = Math.round((float)width/(float)reqWidth); 
    } 
    //if value is greater than 1,sub sample the original image 
    options.inSampleSize = inSampleSize; 
    // Decode bitmap with inSampleSize set 
    options.inJustDecodeBounds = false; 
    return BitmapFactory.decodeFile(path, options); 
} 
} 

我从this和this取出的参考。