Android開發中dp,sp和px之間的轉換

本文轉載於 http://blog.csdn.net/student9128/article/details/53932470

眾所周知，在Android開發中dp和px,sp和px之間的轉換時必不可少的，下面將轉換的代碼記錄下來：

public class DisplayUtils {
    /**
     * convert px to its equivalent dp
     * 
     * 將px轉換為與之相等的dp
     */
    public static int px2dp(Context context, float pxValue) {
        final float scale =  context.getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }


    /**
     * convert dp to its equivalent px
     * 
     * 將dp轉換為與之相等的px
     */
    public static int dp2px(Context context, float dipValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dipValue * scale + 0.5f);
    }


    /**
     * convert px to its equivalent sp 
     * 
     * 將px轉換為sp
     */
    public static int px2sp(Context context, float pxValue) {
        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
        return (int) (pxValue / fontScale + 0.5f);
    }


    /**
     * convert sp to its equivalent px
     * 
     * 將sp轉換為px
     */
    public static int sp2px(Context context, float spValue) {
        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
        return (int) (spValue * fontScale + 0.5f);
    }

同時系統也提供了TypedValue類幫助我們轉換

/**
* convert dp to its equivalent px
*/
protected int dp2px(int dp){
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp,getResources().getDisplayMetrics());
    }

/**
* convert sp to its equivalent px
*/
protected int sp2px(int sp){
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, sp,getResources().getDisplayMetrics());
    }