Project Knowledge (vi)

How to put view into ViewGroup in code (combined control)

Need: To create a similar Baidu post-refresh button, but do not want to use XML to layout.

Requirement: Create a view class to inherit Relativelayout and then populate the ImageView in Relativelayout

So how to put ImageView into Relativelayout from Java code.

 Public classRefreshviewextendsRelativelayoutImplementsview.onclicklistener{PrivateImageView Mivrefresh; PrivateContext Mcontext;  PublicRefreshview (Context context) {Super(context);    Initview (context); }     PublicRefreshview (Context context, AttributeSet attrs) {Super(context, attrs);    Initview (context); }     PublicRefreshview (context context, AttributeSet attrs,intdefstyleattr) {        Super(context, attrs, defstyleattr);    Initview (context); }    Private voidInitview (Context context) {Mcontext=context; //①, creating a View instanceMivrefresh =NewImageView (context);        Mivrefresh.setimageresource (R.mipmap.ic_launcher); //②, creating layoutsLayoutparams params =Newlayoutparams (ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT); //here is the most important: AddRule () Set the layout constraints, here is relativelayout so use the relativelayout constraints, as XMLParams.addrule (relativelayout.center_in_parent,true); //add into RelativelayoutAddView (Mivrefresh,params); }}    

RefreshviewSecond, the realization of the imageview in the picture rotation repeated playback effect

Knowledge: ①, how to create Animation② in code and XML, how to configure a animation interpolator, how to repeat ③, how to call animation

Here you select the code to create the animation

PrivateImageView Mivrefresh;Private voidSetrefreshanimstart () {Linearinterpolator Lin=NewLinearinterpolator (); //Create Animation animation.relative_to_self to represent itself as a pointAnimation am =NewRotateanimation (0, +360, Animation.relative_to_self,0.5f, Animation.relative_to_self,0.5f ); //execution time of animation start to end (1000 = 1 seconds)Am. Setduration (1000 ); //Animation Repeat count (-1 means repeat)Am.setrepeatcount (-1 ); //Setting the InterpolatorAm.setinterpolator (Lin); //View Control call animationmivrefresh.startanimation (AM); Isfinish=false; }

Refreshview

Project Knowledge (vi)