Android ProgressBar详解以及自定义

/**

   * Create a new progress bar with range 0...100 and initial progress of 0.

   * @param context the application environment

   */

  public ProgressBar(Context context) {

      this(context, null);

  }

  

  public ProgressBar(Context context, AttributeSet attrs) {

      this(context, attrs, com.android.internal.R.attr.progressBarStyle);

  }

  public ProgressBar(Context context, AttributeSet attrs, int defStyle) {

      this(context, attrs, defStyle, 0);

  }

  /**

   * @hide

   */

  public ProgressBar(Context context, AttributeSet attrs, int defStyle, int styleRes) {

      super(context, attrs, defStyle);

      mUiThreadId = Thread.currentThread().getId();

      initProgressBar();

      TypedArray a =

          context.obtainStyledAttributes(attrs, R.styleable.ProgressBar, defStyle, styleRes);

      

      mNoInvalidate = true;

      

      Drawable drawable = a.getDrawable(R.styleable.ProgressBar_progressDrawable);

      if (drawable != null) {

          drawable = tileify(drawable, false);

          // Calling this method can set mMaxHeight, make sure the corresponding

          // XML attribute for mMaxHeight is read after calling this method

          setProgressDrawable(drawable);

      }

      mDuration = a.getInt(R.styleable.ProgressBar_indeterminateDuration, mDuration);

      mMinWidth = a.getDimensionPixelSize(R.styleable.ProgressBar_minWidth, mMinWidth);

      mMaxWidth = a.getDimensionPixelSize(R.styleable.ProgressBar_maxWidth, mMaxWidth);

      mMinHeight = a.getDimensionPixelSize(R.styleable.ProgressBar_minHeight, mMinHeight);

      mMaxHeight = a.getDimensionPixelSize(R.styleable.ProgressBar_maxHeight, mMaxHeight);

      mBehavior = a.getInt(R.styleable.ProgressBar_indeterminateBehavior, mBehavior);

      final int resID = a.getResourceId(

              com.android.internal.R.styleable.ProgressBar_interpolator,

              android.R.anim. linear_interpolator); // default to linear interpolator

      if (resID > 0) {

          setInterpolator(context, resID);

      }

      setMax(a.getInt(R.styleable.ProgressBar_max, mMax));

      setProgress(a.getInt(R.styleable.ProgressBar_progress, mProgress));

      setSecondaryProgress(

              a.getInt(R.styleable.ProgressBar_secondaryProgress, mSecondaryProgress));

      drawable = a.getDrawable(R.styleable.ProgressBar_indeterminateDrawable);

      if (drawable != null) {

          drawable = tileifyIndeterminate(drawable);

          setIndeterminateDrawable(drawable);

      }

      mOnlyIndeterminate = a.getBoolean(

              R.styleable.ProgressBar_indeterminateOnly, mOnlyIndeterminate);

      mNoInvalidate = false;

      setIndeterminate( mOnlyIndeterminate || a.getBoolean(

              R.styleable.ProgressBar_indeterminate, mIndeterminate));

      mMirrorForRtl = a.getBoolean(R.styleable.ProgressBar_mirrorForRtl, mMirrorForRtl);

      a.recycle();

  }