DensityUtils 用來做Android設備屏幕的單位轉化工具類

    import android.content.Context;

    import android.util.TypedValue;


//常用單位轉換的輔助類  
public class DensityUtils  
{  
    private DensityUtils()  
    {  
        /* cannot be instantiated */  
        throw new UnsupportedOperationException("cannot be instantiated");  
    }  

    /** 
     * dp轉px 
     *  
     * @param context 
     * @param val 
     * @return 
     */  
    public static int dp2px(Context context, float dpVal)  
    {  
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,  
                dpVal, context.getResources().getDisplayMetrics());  
    }  

    /** 
     * sp轉px 
     *  
     * @param context 
     * @param val 
     * @return 
     */  
    public static int sp2px(Context context, float spVal)  
    {  
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,  
                spVal, context.getResources().getDisplayMetrics());  
    }  

    /** 
     * px轉dp 
     *  
     * @param context 
     * @param pxVal 
     * @return 
     */  
    public static float px2dp(Context context, float pxVal)  
    {  
        final float scale = context.getResources().getDisplayMetrics().density;  
        return (pxVal / scale);  
    }  

    /** 
     * px轉sp 
     *  
     * @param fontScale 
     * @param pxVal 
     * @return 
     */  
    public static float px2sp(Context context, float pxVal)  
    {  
        return (pxVal / context.getResources().getDisplayMetrics().scaledDensity);  
    }  

}  </pre>