setImageBitmap不显示

Question

单击时，我的应用可在相机和图库之间进行选择，然后该图片将显示在 ImageView 中。我最初尝试显示完整图像，然后尝试使用位图方式，但没有任何效果。我只是得到一个空白的图像视图。请给我一些关于我做错了什么的指导，并在必要时要求澄清：

相机/画廊照片代码：

Uri outputFileUri;
private void openImageIntent() {
    // Determine Uri of camera image to save.
    final File root = new File(Environment.getExternalStorageDirectory() + File.separator + "MyDir" + File.separator);
    root.mkdirs();
    final String fname = "img_" + System.currentTimeMillis() + ".jpg";
    final File sdImageMainDirectory = new File(root, fname);
    outputFileUri = Uri.fromFile(sdImageMainDirectory);
    // Camera.
    final List<Intent> cameraIntents = new ArrayList<Intent>();
    final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    final PackageManager packageManager = getPackageManager();
    final List<ResolveInfo> listCam = packageManager.queryIntentActivities(captureIntent, 0);
    for(ResolveInfo res : listCam) {
        final String packageName = res.activityInfo.packageName;
        final Intent intent = new Intent(captureIntent);
        intent.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
        intent.setPackage(packageName);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
        cameraIntents.add(intent);
    }
    // Filesystem.
    final Intent galleryIntent = new Intent();
    galleryIntent.setType("image/*");
    galleryIntent.setAction(Intent.ACTION_GET_CONTENT);
    // Chooser of filesystem options.
    final Intent chooserIntent = Intent.createChooser(galleryIntent, "Select Source");
    // Add the camera options.
    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, cameraIntents.toArray(new Parcelable[]{}));
    startActivityForResult(chooserIntent, 0);
}


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent returnIntent) {
    super.onActivityResult(resultCode, requestCode, returnIntent);
    if(requestCode == 0) {
        if(resultCode == RESULT_OK) {
            final boolean isCamera;
            if(returnIntent == null) {
                isCamera = true;
            }
            else
            {
                final String action = returnIntent.getAction();
                if(action == null) {
                    isCamera = false;
                }
                else {
                    isCamera = action.equals(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                }
            }
            Uri selectedImageUri;
            if(isCamera) {
                selectedImageUri = outputFileUri;
                mainImage.setImageURI(selectedImageUri); //trying full image
            }
            else {
                selectedImageUri = returnIntent == null ? null : returnIntent.getData();
                try {
                    Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImageUri);
                    mainImage.setImageBitmap(bitmap); //trying bitmap
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

Answer 1

现在你可以使用毕加索图书馆:D

Picasso.with(context)
    .load(item.getPhotoUri())
    .resize(512,512)
    .placeholder(R.drawable.noimage)
    .error(R.drawable.error_image)
    .into(photo);

Answer 2

如果你想用相机拍摄图像，你可以这样做:

public void fromCamera(){

    String path= Environment.getExternalStorageDirectory().getPath() + "/DCIM/Camera/";
    File file = new File(path,"IMG_"+System.currentTimeMillis()+".jpg");
    file.getParentFile().mkdirs();
    try {
        file.createNewFile();
    }catch (IOException e) {
        e.printStackTrace();
    }
    mPicCaptureUri = Uri.fromFile(file);
    Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, mPicCaptureUri);
    startActivityForResult(intent, REQUEST_CAMERA);

}

如果你想要图库中的图像，那么：

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.setType("image/*");
    startActivityForResult(Intent.createChooser(intent, getString(R.string.select_file)), REQUEST_GALLERY);

在onActivityResult上，您可以获取所选图像的图像路径，并在图像视图中设置图像。。。。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if(resultCode == RESULT_OK){
        if (requestCode == REQUEST_GALLERY && data != null && data.getData() != null) {

            Uri selectedImageUri = data.getData();

            //do set your image here


        }else if(requestCode == REQUEST_CAMERA){

            if(mPicCaptureUri!=null){
                //do try to set image here
            }
        }
    }
}

不要忘记在顶部将mPicCapture Uri定义为：

private Uri mPicCaptureUri = null;

您可以从上面的代码中获取想法..它可能会帮助你

Answer 3

您的问题是由于图像大小，您的ImageView无法显示图像。我用ImageView试试这个代码，如下所示

    <ImageView
    android:id="@+id/mainImage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:src="@drawable/abc_ab_bottom_solid_dark_holo" />

如果像这样将高度和宽度与dp一起使用

    android:layout_width="100dp"
    android:layout_height="100dp"

您需要压缩位图以在ImageView中显示它。编辑要转换的代码

if(isCamera) {
                selectedImageUri = outputFileUri;
                try {
                    Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImageUri);//You can use this bitmap if need full image to further use 
                    Bitmap bitmap2 = Bitmap.createScaledBitmap(bitmap,  600 ,600, true);//this bitmap2 you can use only for display
                    mainImage.setImageBitmap(bitmap2); //trying full image
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
            else {
                selectedImageUri = returnIntent == null ? null : returnIntent.getData();
                try {
                    Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImageUri);
                    bitmap = Bitmap.createScaledBitmap(bitmap,  600 ,600, true);
                    mainImage.setImageBitmap(bitmap); //trying bitmap
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }