View处理常用方法封装
处理View常用的一些方法:Drawable和Bitmap互相转换,Bitmap改变大小,dp、px互相转换,sp、px互相转换,根据Id查找Drawable,获取屏幕大小等方法。
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.WindowManager;
/**
* 剪裁视图的工具类
* Created by ChenSS on 2016/9/19.
*/
public class ViewHelper {
/***
* 画布重绘的方式改变Bitmap的大小
*/
public static Bitmap zoomImage(Bitmap bgimage, double newWidth,
double newHeight) {
// 获取这个图片的宽和高
float width = bgimage.getWidth();
float height = bgimage.getHeight();
// 创建操作图片用的matrix对象
Matrix matrix = new Matrix();
// 计算宽高缩放率
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// 缩放图片动作
matrix.postScale(scaleWidth, scaleHeight);
Bitmap bitmap = Bitmap.createBitmap(bgimage, 0, 0, (int) width,
(int) height, matrix, true);
bgimage.recycle();
return bitmap;
}
/**
* Drawable转Bitamp方法
*/
public Bitmap drawableToBitmap(Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bd = (BitmapDrawable) drawable;
return bd.getBitmap();
}
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ?
Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
Bitmap bitmap = Bitmap.createBitmap(w, h, config);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, w, h);
drawable.draw(canvas);
return bitmap;
}
/**
* 寻找并裁剪图片(正方形)
*/
public static Drawable findImgAsSquare(Context context, int id, int sidedp) {
Drawable drawable = ContextCompat.getDrawable(context, id);
int px = ViewHelper.dip2px(context, sidedp);
drawable.setBounds(0, 0, px, px);
return drawable;
}
/**
* 寻找Drawable
*/
public static Drawable findDrawableById(Context context, int id) {
return ContextCompat.getDrawable(context, id);
}
/**
* 将px值转换为dip或dp值,保证尺寸大小不变
*/
public static int px2dip(Context context, float pxValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (pxValue / scale + 0.5f);
}
/**
* 将dip或dp值转换为px值,保证尺寸大小不变
*/
public static int dip2px(Context context, float dipValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dipValue * scale + 0.5f);
}
/**
* 将px值转换为sp值,保证文字大小不变
*/
public static int px2sp(Context context, float pxValue) {
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (pxValue / fontScale + 0.5f);
}
/**
* 将sp值转换为px值,保证文字大小不变
*/
public static int sp2px(Context context, float spValue) {
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (spValue * fontScale + 0.5f);
}
/**
* 以Point对象返回屏幕大小(可使用Context代替Activity)
*/
public static Point getScreenSize(Activity activity) {
Display display = activity.getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
return size;
}
/**
* 以Point对象返回屏幕大小
*/
public static Point getScreenHW(Context context) {
Point point = new Point();
WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics dm = new DisplayMetrics();
manager.getDefaultDisplay().getMetrics(dm);
point.x = dm.widthPixels;
point.y = dm.heightPixels;
return point;
}
/**
* 获取屏幕的宽度
*/
public static int getScreenW(Context context) {
return getScreenHW(context).x;
}
/**
* 获取屏幕的高度
*/
public static int getScreenH(Context context) {
return getScreenHW(context).y;
}
}
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