2016-9-23

2016-9-23

1.view移除背景後再設置背景導致padding無效

public void setBackgroundDrawable (Drawable background)
Added in API level 1
This method was deprecated in API level 16. use setBackground(Drawable) instead

public void setBackground (Drawable background)
Added in API level 16
Set the background to a given Drawable, or remove the background. If the background has padding, this View's padding is set to the background's padding. However, when a background is removed, this View's padding isn't touched. If setting the padding is desired, please use setPadding(int, int, int, int).

在再次設置背景前,需要先獲取padding,如下:
    int paddingLeft = button.getPaddingLeft();
    int paddingRight = button.getPaddingRight();
    int paddingTop = button.getPaddingTop();
    int paddingBottom = button.getBottom();
    button.setBackgroundDrawable(new ColorDrawable());
    button.setPadding(paddingLeft,paddingTop,paddingRight, paddingBottom);

2.android自定義view時,在頁面被回收時保存變量

    @Override  
    protected Parcelable onSaveInstanceState() {  
        Bundle bundle = new Bundle();  
        Parcelable superData = super.onSaveInstanceState();  
        bundle.putParcelable("super_data", superData);  
        bundle.putParcelableArrayList("save_data", mRects);  
        return bundle;  
    }  

    @Override  
    protected void onRestoreInstanceState(Parcelable state) {  
        Bundle bundle = (Bundle) state;  
        Parcelable superData = bundle.getParcelable("super_data");  
        mRects = bundle.getParcelableArrayList("save_data");  
        super.onRestoreInstanceState(superData);  
    }  

3.進入sd卡選擇圖片的幾種方式

1.
    Intent localIntent = new Intent();
    localIntent.setType("image/*");
    localIntent.setAction("android.intent.action.GET_CONTENT");
    startActivityForResult(localIntent, PHOTO_PICKED_WITH_DATA);
2.
    Intent localIntent = new Intent();
    localIntent.setType("image/*");
    localIntent.setAction("android.intent.action.GET_CONTENT");
    Intent localIntent2 = Intent.createChooser(localIntent, "請選擇圖片");
    startActivityForResult(localIntent2, PHOTO_PICKED_WITH_DATA);
3.
    Intent localIntent3 = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(localIntent3, PHOTO_PICKED_WITH_DATA);