尺寸相关→SizeUtils

	import android.util.DisplayMetrics;
	import android.util.TypedValue;
	import android.view.View;
	import android.view.ViewGroup;
	/**
	* <pre>
	* author: Blankj
	* blog : http://blankj.com
	* time : 2016/8/2
	* desc : 尺寸相关工具类
	* </pre>
	*/
	public final class SizeUtils {
	private SizeUtils() {
	throw new UnsupportedOperationException("u can't instantiate me...");
	}
	/**
	* dp转px
	*
	* @param dpValue dp值
	* @return px值
	*/
	public static int dp2px(float dpValue) {
	final float scale = Utils.getContext().getResources().getDisplayMetrics().density;
	return (int) (dpValue * scale + 0.5f);
	}
	/**
	* px转dp
	*
	* @param pxValue px值
	* @return dp值
	*/
	public static int px2dp( float pxValue) {
	final float scale = Utils.getContext().getResources().getDisplayMetrics().density;
	return (int) (pxValue / scale + 0.5f);
	}
	/**
	* sp转px
	*
	* @param spValue sp值
	* @return px值
	*/
	public static int sp2px(float spValue) {
	final float fontScale = Utils.getContext().getResources().getDisplayMetrics().scaledDensity;
	return (int) (spValue * fontScale + 0.5f);
	}
	/**
	* px转sp
	*
	* @param pxValue px值
	* @return sp值
	*/
	public static int px2sp( float pxValue) {
	final float fontScale = Utils.getContext().getResources().getDisplayMetrics().scaledDensity;
	return (int) (pxValue / fontScale + 0.5f);
	}
	/**
	* 各种单位转换
	* <p>该方法存在于TypedValue</p>
	*
	* @param unit 单位
	* @param value 值
	* @param metrics DisplayMetrics
	* @return 转换结果
	*/
	public static float applyDimension(int unit, float value, DisplayMetrics metrics) {
	switch (unit) {
	case TypedValue.COMPLEX_UNIT_PX:
	return value;
	case TypedValue.COMPLEX_UNIT_DIP:
	return value * metrics.density;
	case TypedValue.COMPLEX_UNIT_SP:
	return value * metrics.scaledDensity;
	case TypedValue.COMPLEX_UNIT_PT:
	return value * metrics.xdpi * (1.0f / 72);
	case TypedValue.COMPLEX_UNIT_IN:
	return value * metrics.xdpi;
	case TypedValue.COMPLEX_UNIT_MM:
	return value * metrics.xdpi * (1.0f / 25.4f);
	}
	return 0;
	}
	/**
	* 在onCreate中获取视图的尺寸
	* <p>需回调onGetSizeListener接口，在onGetSize中获取view宽高</p>
	* <p>用法示例如下所示</p>
	* <pre>
	* SizeUtils.forceGetViewSize(view, new SizeUtils.onGetSizeListener() {
	* Override
	* public void onGetSize(View view) {
	* view.getWidth();
	* }
	* });
	* </pre>
	*
	* @param view 视图
	* @param listener 监听器
	*/
	public static void forceGetViewSize(final View view, final onGetSizeListener listener) {
	view.post(new Runnable() {
	@Override
	public void run() {
	if (listener != null) {
	listener.onGetSize(view);
	}
	}
	});
	}
	/**
	* 获取到View尺寸的监听
	*/
	public interface onGetSizeListener {
	void onGetSize(View view);
	}
	/**
	* 测量视图尺寸
	*
	* @param view 视图
	* @return arr[0]: 视图宽度, arr[1]: 视图高度
	*/
	public static int[] measureView(View view) {
	ViewGroup.LayoutParams lp = view.getLayoutParams();
	if (lp == null) {
	lp = new ViewGroup.LayoutParams(
	ViewGroup.LayoutParams.MATCH_PARENT,
	ViewGroup.LayoutParams.WRAP_CONTENT
	);
	}
	int widthSpec = ViewGroup.getChildMeasureSpec(0, 0, lp.width);
	int lpHeight = lp.height;
	int heightSpec;
	if (lpHeight > 0) {
	heightSpec = View.MeasureSpec.makeMeasureSpec(lpHeight, View.MeasureSpec.EXACTLY);
	} else {
	heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
	}
	view.measure(widthSpec, heightSpec);
	return new int[]{view.getMeasuredWidth(), view.getMeasuredHeight()};
	}
	/**
	* 获取测量视图宽度
	*
	* @param view 视图
	* @return 视图宽度
	*/
	public static int getMeasuredWidth(View view) {
	return measureView(view)[0];
	}
	/**
	* 获取测量视图高度
	*
	* @param view 视图
	* @return 视图高度
	*/
	public static int getMeasuredHeight(View view) {
	return measureView(view)[1];
	}
	}