Android之从相册访问照片

从上一篇博客的基础上修改：地址

首先是activitymain.xml:

<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:id="@+id/take_photo"
        android:text="拍照"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/choose_from_album"
        android:text="Choosefromalbum"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <ImageView
        android:id="@+id/picture"
        android:layout_gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

然后修改MainActivity

public static final int chose_puhoto=2;

Button chose_from_album=(Button)findViewById(R.id.choose_from_album);
chose_from_album.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED)
        {
            ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
        }

//
        else{
            openAlbum();
        }
    }
});

private  void openAlbum(){
        Intent intent=new Intent("android.intent.action.GET_CONTENT");
        intent.setType("image/*");
        startActivityForResult(intent,chose_puhoto);//打开相册
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode){
    case 1:
        if(grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION_GRANTED){
            openAlbum();
        }
        else {
            Toast.makeText(this,"你拒绝了允许",Toast.LENGTH_LONG).show();
        }
        break;
        default:
}

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode){
        case TAKE_PHOTP:
            if(resultCode==RESULT_OK){
                try {
                    Bitmap bitmap= BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                    imageView.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }

            }
            break;
        case chose_puhoto:
            if(resultCode==RESULT_OK){
                if(Build.VERSION.SDK_INT>=19){
                    handleImageOnKitKat(data);

                }
                else{
                    handleImageBeforeKitKate(data);
                }
            }
            break;
            default:
                break;
    }

}

private void handleImageOnKitKat(Intent data){
String imagePath=null;
Uri uri=data.getData();
    if(DocumentsContract.isDocumentUri(MainActivity.this,uri)){
        String docId=DocumentsContract.getDocumentId(uri);
        if("com.android.providers.media.documents".equals(uri.getAuthority())){
            String id=docId.split(":")[1];
            String selection=MediaStore.Images.Media._ID+"="+id;
            imagePath=getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,selection);

        }
        else if("com.android.providers.downloads.documents".equals(uri.getAuthority())){
            Uri contentUri= ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"),Long.valueOf(docId));
            imagePath=getImagePath(contentUri,null);
        }
    }
    else if("content".equalsIgnoreCase(uri.getScheme())){
        imagePath=getImagePath(uri,null);
    }
    else if("file".equalsIgnoreCase(uri.getScheme())){
        imagePath=uri.getPath();
    }
    displayImage(imagePath);
}
private void handleImageBeforeKitKate(Intent data){
    Uri uri=data.getData();
    String imagePath=getImagePath(uri,null);
    displayImage(imagePath);
}

private String getImagePath(Uri uri,String selection){
    String path=null;
    Cursor cursor=getContentResolver().query(uri,null,selection,null,null);
    if(cursor!=null){
        if(cursor.moveToFirst()){
            path=cursor.getString( cursor.getColumnIndex(MediaStore.Images.Media.DATA));
        }
        cursor.close();
    }
    return path;
}
private void displayImage(String imagePath){
    if(imagePath!=null){
        Bitmap bitmap=BitmapFactory.decodeFile(imagePath);
        imageView.setImageBitmap(bitmap);
    }
    else{
        Toast.makeText(this,"failed to get Image",Toast.LENGTH_LONG).show();
    }
}