TextView setCompoundDrawables()

TextView的 setCompoundDrawables(Drawable left, Drawable top, Drawable right, Drawable bottom)、setCompoundDrawablesWithIntrinsicBounds(int left, int top, int right, int bottom)、setCompoundDrawablesWithIntrinsicBounds(Drawable left, Drawable top,  Drawable right, Drawable bottom)三个方法可用于给TextView设置图片，其中setCompoundDrawables(Drawable left, Drawable top, Drawable right, Drawable bottom)方法传入的Drawable必须已调用Drawable.setBounds(Rect bounds)方法给图片设置边界，其他两个方法保持传入图片本质的边界。

    /**     * Sets the Drawables (if any) to appear to the left of, above,     * to the right of, and below the text.  Use null if you do not     * want a Drawable there.  The Drawables must already have had     * {@link Drawable#setBounds} called.     *     * @attr ref android.R.styleable#TextView_drawableLeft     * @attr ref android.R.styleable#TextView_drawableTop     * @attr ref android.R.styleable#TextView_drawableRight     * @attr ref android.R.styleable#TextView_drawableBottom     */    public void setCompoundDrawables(Drawable left, Drawable top,                                     Drawable right, Drawable bottom) {        Drawables dr = mDrawables;        final boolean drawables = left != null || top != null                || right != null || bottom != null;        if (!drawables) {            // Clearing drawables...  can we free the data structure?            if (dr != null) {                if (dr.mDrawablePadding == 0) {                    mDrawables = null;                } else {                    // We need to retain the last set padding, so just clear                    // out all of the fields in the existing structure.                    if (dr.mDrawableLeft != null) dr.mDrawableLeft.setCallback(null);                    dr.mDrawableLeft = null;                    if (dr.mDrawableTop != null) dr.mDrawableTop.setCallback(null);                    dr.mDrawableTop = null;                    if (dr.mDrawableRight != null) dr.mDrawableRight.setCallback(null);                    dr.mDrawableRight = null;                    if (dr.mDrawableBottom != null) dr.mDrawableBottom.setCallback(null);                    dr.mDrawableBottom = null;                    dr.mDrawableSizeLeft = dr.mDrawableHeightLeft = 0;                    dr.mDrawableSizeRight = dr.mDrawableHeightRight = 0;                    dr.mDrawableSizeTop = dr.mDrawableWidthTop = 0;                    dr.mDrawableSizeBottom = dr.mDrawableWidthBottom = 0;                }            }        } else {            if (dr == null) {                mDrawables = dr = new Drawables(getContext());            }            mDrawables.mOverride = false;            if (dr.mDrawableLeft != left && dr.mDrawableLeft != null) {                dr.mDrawableLeft.setCallback(null);            }            dr.mDrawableLeft = left;            if (dr.mDrawableTop != top && dr.mDrawableTop != null) {                dr.mDrawableTop.setCallback(null);            }            dr.mDrawableTop = top;            if (dr.mDrawableRight != right && dr.mDrawableRight != null) {                dr.mDrawableRight.setCallback(null);            }            dr.mDrawableRight = right;            if (dr.mDrawableBottom != bottom && dr.mDrawableBottom != null) {                dr.mDrawableBottom.setCallback(null);            }            dr.mDrawableBottom = bottom;            final Rect compoundRect = dr.mCompoundRect;            int[] state;            state = getDrawableState();            if (left != null) {                left.setState(state);                left.copyBounds(compoundRect);                left.setCallback(this);                dr.mDrawableSizeLeft = compoundRect.width();                dr.mDrawableHeightLeft = compoundRect.height();            } else {                dr.mDrawableSizeLeft = dr.mDrawableHeightLeft = 0;            }            if (right != null) {                right.setState(state);                right.copyBounds(compoundRect);                right.setCallback(this);                dr.mDrawableSizeRight = compoundRect.width();                dr.mDrawableHeightRight = compoundRect.height();            } else {                dr.mDrawableSizeRight = dr.mDrawableHeightRight = 0;            }            if (top != null) {                top.setState(state);                top.copyBounds(compoundRect);                top.setCallback(this);                dr.mDrawableSizeTop = compoundRect.height();                dr.mDrawableWidthTop = compoundRect.width();            } else {                dr.mDrawableSizeTop = dr.mDrawableWidthTop = 0;            }            if (bottom != null) {                bottom.setState(state);                bottom.copyBounds(compoundRect);                bottom.setCallback(this);                dr.mDrawableSizeBottom = compoundRect.height();                dr.mDrawableWidthBottom = compoundRect.width();            } else {                dr.mDrawableSizeBottom = dr.mDrawableWidthBottom = 0;            }        }        // Save initial left/right drawables        if (dr != null) {            dr.mDrawableLeftInitial = left;            dr.mDrawableRightInitial = right;        }        resetResolvedDrawables();        resolveDrawables();        invalidate();        requestLayout();    }    /**     * Sets the Drawables (if any) to appear to the left of, above,     * to the right of, and below the text.  Use 0 if you do not     * want a Drawable there. The Drawables' bounds will be set to     * their intrinsic bounds.     *     * @param left Resource identifier of the left Drawable.     * @param top Resource identifier of the top Drawable.     * @param right Resource identifier of the right Drawable.     * @param bottom Resource identifier of the bottom Drawable.     *     * @attr ref android.R.styleable#TextView_drawableLeft     * @attr ref android.R.styleable#TextView_drawableTop     * @attr ref android.R.styleable#TextView_drawableRight     * @attr ref android.R.styleable#TextView_drawableBottom     */    @android.view.RemotableViewMethod    public void setCompoundDrawablesWithIntrinsicBounds(int left, int top, int right, int bottom) {        final Resources resources = getContext().getResources();        setCompoundDrawablesWithIntrinsicBounds(left != 0 ? resources.getDrawable(left) : null,                top != 0 ? resources.getDrawable(top) : null,                right != 0 ? resources.getDrawable(right) : null,                bottom != 0 ? resources.getDrawable(bottom) : null);    }    /**     * Sets the Drawables (if any) to appear to the left of, above,     * to the right of, and below the text.  Use null if you do not     * want a Drawable there. The Drawables' bounds will be set to     * their intrinsic bounds.     *     * @attr ref android.R.styleable#TextView_drawableLeft     * @attr ref android.R.styleable#TextView_drawableTop     * @attr ref android.R.styleable#TextView_drawableRight     * @attr ref android.R.styleable#TextView_drawableBottom     */    public void setCompoundDrawablesWithIntrinsicBounds(Drawable left, Drawable top,            Drawable right, Drawable bottom) {        if (left != null) {            left.setBounds(0, 0, left.getIntrinsicWidth(), left.getIntrinsicHeight());        }        if (right != null) {            right.setBounds(0, 0, right.getIntrinsicWidth(), right.getIntrinsicHeight());        }        if (top != null) {            top.setBounds(0, 0, top.getIntrinsicWidth(), top.getIntrinsicHeight());        }        if (bottom != null) {            bottom.setBounds(0, 0, bottom.getIntrinsicWidth(), bottom.getIntrinsicHeight());        }        setCompoundDrawables(left, top, right, bottom);    }

setCompoundDrawablesRelative(Drawable start, Drawable top,Drawable end, Drawable bottom)、setCompoundDrawablesRelativeWithIntrinsicBounds(int start, int top, int end,int bottom)、setCompoundDrawablesRelativeWithIntrinsicBounds(Drawable start, Drawable top,Drawable end, Drawable bottom)类似。