Android UI Development Topic (iii) various drawable

This time we mainly explain the various drawable under the Android platform, here in the SDK Android.graphics.drawable package can see a variety of drawable classes as many as more than 10 kinds, what is the relationship between them and the difference ?

First, animationdrawable

As the name suggests, this class mainly represents animation graphics classes, you can achieve the effect of frame play, the following code shows such as

1. Define a cwj_animation.xml to be placed in the Res/drawable directory, where the defined attribute duration is a delay, in milliseconds, and the OneShot property indicates whether to play only once and the content is:

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2. Calling in Java is also simple

ImageView img = (imageview) Findviewbyid (r.id.cwj_image); First declare a ImageView object in the XML layout file

Img.setbackgroundresource (r.drawable.cwj_animation); The XML file that we just animation defined

Animationdrawable frameanimation = (animationdrawable) img.getbackground (); Constructing Animationdrawable objects

Frameanimation.start ()//start to play animation

3. The Animationdrawable class also provides some common methods as follows:

void Stop () stop

void Addframe (drawable frame, int duration) Adds a frame, similar to the layout in XML

drawable getframe (int index) returns the drawable graphic of a frame

int Getnumberofframes () returns the total number of animation frames

Boolean isoneshot () play only once

Whether the Boolean isrunning () is playing

Second, bitmapdrawable

The bitmap object for scaling and morphing in the Android platform is represented by the Bitmapdrawable class, and its construction method is simple, Because this class inherits from Android.graphics.drawable.Drawable, the relative drawable provides more information about how bitmaps are manipulated, and the main construction methods are as follows:

Bitmapdrawable ()//directly constructs an empty object, which is not recommended, and the SDK is labeled deprecated. May not be used in the future.

Bitmapdrawable (Resources Res)//constructed from a resource

Bitmapdrawable (Bitmap Bitmap)//is constructed directly from the Bitmap object, but is not recommended, but wants to use the next

Bitmapdrawable (Resources res, Bitmap Bitmap)//create set initial resolution from Bitmap from Res

Bitmapdrawable (String filepath)//is constructed from a specific file path and is not recommended, but is the next better

Bitmapdrawable (Resources res, String filepath)/IBID.

Bitmapdrawable (InputStream is)/is constructed from the input stream, the following method is also recommended

Bitmapdrawable (Resources Res, InputStream is)//IBID.

In the Bitmapdrawable class, relative to the Drawable class mainly add the following methods, are more practical:

Final Bitmap Getbitmap () gets a Bitmap object

int getopacity ()//Gain Transparency

void Setantialias (Boolean AA)//anti-aliasing

void Settargetdensity (Canvas Canvas)//Set Target Canvas density

void Settargetdensity (Displaymetrics metrics)

Third, clipdrawable

Colordrawable

Drawable

Gradientdrawable

Insetdrawable

Layerdrawable

Levellistdrawable

Ninepatchdrawable

Paintdrawable

Picturedrawable

Rotatedrawable

Scaledrawable

Shapedrawable

Statelistdrawable

Transitiondrawable

The above types are generally less common in development, mainly based on the use of the base class, the Android interior of the multiple widget base control used, interested users can view open source git in the relevant content.