自适应网络加载的图片（按比例缩小）

来源：互联网发布：西安vb舞蹈工作室官网编辑：程序博客网时间：2024/04/30 15:55

网络下载的图片如果加载到屏幕上由于其尺寸不定所以要对其进行统一管理，
一般是解析json先得到图片路径（附带图片的width，height）
对图片统一管理方案
float width
float height

width = 屏幕w
height = 图片h/（图片w/屏幕w）
imageView.setLayoutParams(new LinearLayout.LayoutParams(width, height));

实例

  private int maxWidth;  private int maxHeight;   maxWidth = ToolsUtil.getWidthInPx(context)-20;   maxHeight = ToolsUtil.getHeightInPx(context) - ToolsUtil.getStatusHeight(context) -                ToolsUtil.dip2px(context, 96);//屏幕高度-状态栏        float scale = (float)imageBean.getWidth()/(float)maxWidth;        int height = (int)(imageBean.getHeight()/scale);        if(height>maxHeight){            height = maxHeight;        }       imageView.setLayoutParams(new LinearLayout.LayoutParams(maxWidth, height));

ToolsUtil类

package com.jsu.whr;import android.content.Context;import android.net.ConnectivityManager;import android.net.NetworkInfo;public class ToolsUtil {public static final int getHeightInPx(Context context) {final int height = context.getResources().getDisplayMetrics().heightPixels;return height;}public static final int getWidthInPx(Context context) {final int width = context.getResources().getDisplayMetrics().widthPixels;return width;}public static final int getHeightInDp(Context context) {final float height = context.getResources().getDisplayMetrics().heightPixels;int heightInDp = px2dip(context, height);return heightInDp;}public static final int getWidthInDp(Context context) {final float width = context.getResources().getDisplayMetrics().widthPixels;int widthInDp = px2dip(context, width);return widthInDp;}public static int dip2px(Context context, float dpValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (dpValue * scale + 0.5f);}public static int px2dip(Context context, float pxValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (pxValue / scale + 0.5f);}public static int px2sp(Context context, float pxValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (pxValue / scale + 0.5f);}public static int sp2px(Context context, float spValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (spValue * scale + 0.5f);}/** * 获得状态栏的高度 *  * @param context * @return */public static int getStatusHeight(Context context) {int statusHeight = -1;try {Class<?> clazz = Class.forName("com.android.internal.R$dimen");Object object = clazz.newInstance();int height = Integer.parseInt(clazz.getField("status_bar_height").get(object).toString());statusHeight = context.getResources().getDimensionPixelSize(height);} catch (Exception e) {e.printStackTrace();}return statusHeight;}/** * 判断网络是否可用 * @param context * @return */public static boolean isNetworkAvailable(Context context) {ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);if (cm != null) {//如果仅仅是用来判断网络连接//则可以使用 cm.getActiveNetworkInfo().isAvailable();NetworkInfo[] info = cm.getAllNetworkInfo();if (info != null) {for (int i = 0; i < info.length; i++) {if (info[i].getState() == NetworkInfo.State.CONNECTED) {return true;}}}}return false;}}

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