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原创最新推荐文章于 2026-02-28 23:03:53 发布 660 阅读 AI 写同款· GEO 优化 ›

Flutter Image 参数详解 1.继承关系 Object > Diagnosticablet > DiagnosticableTreet > Widgett > StatefulWidgett > Image 2.介绍一个显示图片的widget，支持图像格式：JPEG，PNG，GIF，动画GIF，WebP，动画WebP，BMP和WBMP 3.创建Image 一共有五种方法: ... 阅读详情

public class ImageUtil {
public static InputStream getRequest(String path) throws Exception {
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
if (conn.getResponseCode() == 200){
return conn.getInputStream();
}
return null;
}
public static byte[] readInputStream(InputStream inStream) throws Exception {
ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
byte[] buffer = new byte[4096];
int len = 0;
while ((len = inStream.read(buffer)) != -1) {
outSteam.write(buffer, 0, len);
}
outSteam.close();
inStream.close();
return outSteam.toByteArray();
}
public static Drawable loadImageFromUrl(String url){
URL m;
InputStream i = null;
try {
m = new URL(url);
i = (InputStream) m.getContent();
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Drawable d = Drawable.createFromStream(i, "src");
return d;
}
public static Drawable getDrawableFromUrl(String url) throws Exception{
return Drawable.createFromStream(getRequest(url),null);
}
public static Bitmap getBitmapFromUrl(String url) throws Exception{
byte[] bytes = getBytesFromUrl(url);
return byteToBitmap(bytes);
}
public static Bitmap getRoundBitmapFromUrl(String url,int pixels) throws Exception{
byte[] bytes = getBytesFromUrl(url);
Bitmap bitmap = byteToBitmap(bytes);
return toRoundCorner(bitmap, pixels);
}
public static Drawable geRoundDrawableFromUrl(String url,int pixels) throws Exception{
byte[] bytes = getBytesFromUrl(url);
BitmapDrawable bitmapDrawable = (BitmapDrawable)byteToDrawable(bytes);
return toRoundCorner(bitmapDrawable, pixels);
}
public static byte[] getBytesFromUrl(String url) throws Exception{
return readInputStream(getRequest(url));
}
public static Bitmap byteToBitmap(byte[] byteArray){
if(byteArray.length!=0){
return BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
}
else {
return null;
}
}
public static Drawable byteToDrawable(byte[] byteArray){
ByteArrayInputStream ins = new ByteArrayInputStream(byteArray);
return Drawable.createFromStream(ins, null);
}
public static byte[] Bitmap2Bytes(Bitmap bm){
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
return baos.toByteArray();
}
public static Bitmap drawableToBitmap(Drawable drawable) {
Bitmap bitmap = Bitmap
.createBitmap(
drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight(),
drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;
}
/**
* 图片去色,返回灰度图片
* @param bmpOriginal 传入的图片
* @return 去色后的图片
*/
public static Bitmap toGrayscale(Bitmap bmpOriginal) {
int width, height;
height = bmpOriginal.getHeight();
width = bmpOriginal.getWidth();
Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
Canvas c = new Canvas(bmpGrayscale);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
cm.setSaturation(0);
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bmpOriginal, 0, 0, paint);
return bmpGrayscale;
}
/**
* 去色同时加圆角
* @param bmpOriginal 原图
* @param pixels 圆角弧度
* @return 修改后的图片
*/
public static Bitmap toGrayscale(Bitmap bmpOriginal, int pixels) {
return toRoundCorner(toGrayscale(bmpOriginal), pixels);
}
/**
* 把图片变成圆角
* @param bitmap 需要修改的图片
* @param pixels 圆角的弧度
* @return 圆角图片
*/
public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
final float roundPx = pixels;
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
/**
* 使圆角功能支持BitampDrawable
* @param bitmapDrawable
* @param pixels
* @return
*/
public static BitmapDrawable toRoundCorner(BitmapDrawable bitmapDrawable, int pixels) {
Bitmap bitmap = bitmapDrawable.getBitmap();
bitmapDrawable = new BitmapDrawable(toRoundCorner(bitmap, pixels));
return bitmapDrawable;
}
}