Android Glide简单用法

Glide ：Google推荐的图片加载库，专注于流畅的滚动。

Glide常见用法：

Glide.with(mContext)
.load(path)
.asGif()
.override(300，300)
.diskCacheStrategy(DiskCacheStrategy.SOURCE)
.placeholder(R.drawable.progressbar)
.thumbnail(1f)
.error(R.drawable.error)
.transform(new MyBitmapTransformation(mContext,10f))
.into(iv);

with:传入对象 Context,Activity,Fragment，Glide与当前传入值的生命周期一致，

在onPause方法，onResume 等方法中可适当控件Glide的状态。

Glide.with(mContext).onStop();

Glide.with(mContext).onDestroy();

Glide.with(mContext).pauseRequests();

Glide.with(mContext).resumeRequests();

load对象: String(文件路径，网络地址)，File(文件资源)，Integer(资源id)；

asGif:表示的gif动画，asBitmap：表示静态图

diskCacheStrategy磁盘缓存策略：

DiskCacheStrategy.RESULT:展示小大的图片缓存

DiskCacheStrategy.ALL; 展示在控件中大小图片尺寸和原图都会缓存

DiskCacheStrategy.NONE：不设置缓存

DiskCacheStrategy.SOURCE：原图缓存

override(300，300) 显示图片的width，height

placeholder(R.drawable.progressbar):目标从加载到展示时的控件的显示状态（多用网络加载动画）

error(R,drawable,error):加载失败时，控件显示的图片。

thumbnail ：缩略图显示传入值(0-1f)

transform: 图片圆角或圆形显示(继承 BitmapTransformation可行)

into(iv) 展示的控件

实现 GlideModule接口

自定义缓存目录，缓存大小

同时在AndroidManifest.xml中将GlideModule定义为

<meta-data android:name="com.inthecheesefactory.lab.glidepicasso.GlideConfiguration"
android:value="GlideModule"/>

public class GlideConfiguration implements GlideModule {

@Override
public void applyOptions(Context context, GlideBuilder builder) {
//设置图片的显示格式ARGB_8888,如果怕图片太耗内存，可以改为DecodeFormat.PREFER_RGB_565
builder.setDecodeFormat(DecodeFormat.PREFER_ARGB_8888);
//设置磁盘缓存目录
String         downloadDirectoryPath=Environment.getExternalStorageDirectory()
//自定义缓存大小
int cacheSize100MegaBytes = 100000000;
glideBuilder.setDiskCache(
new DiskLruCacheFactory(downloadDirectoryPath, cacheSize100MegaBytes)
);
}

@Override
public void registerComponents(Context context, Glide glide) {
// register ModelLoaders here.
}
}

圆形图片显示：

public class GlideCircleTransform extends BitmapTransformation {
public GlideCircleTransform(Context context) {
super(context);
}

@Override
protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {
return circleCrop(pool, toTransform);
}

private static Bitmap circleCrop(BitmapPool pool, Bitmap source) {
if (source == null) return null;

int size = Math.min(source.getWidth(), source.getHeight());
int x = (source.getWidth() - size) / 2;
int y = (source.getHeight() - size) / 2;

// TODO this could be acquired from the pool too
Bitmap squared = Bitmap.createBitmap(source, x, y, size, size);

Bitmap result = pool.get(size, size, Bitmap.Config.ARGB_8888);
if (result == null) {
result = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
}

Canvas canvas = new Canvas(result);
Paint paint = new Paint();
paint.setShader(new BitmapShader(squared, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
paint.setAntiAlias(true);
float r = size / 2f;
canvas.drawCircle(r, r, r, paint);
return result;
}

@Override public String getId() {
return getClass().getName();
}

圆角显示:

public class GlideRoundTransform extends BitmapTransformation {
private static float radius = 0f;

public GlideRoundTransform(Context context) {
this(context, 4);
}

/**
* 通过构造方法来确定圆角的大小
* @param context
* @param dp
*/
public GlideRoundTransform(Context context, int dp) {
super(context);
this.radius = Resources.getSystem().getDisplayMetrics().density * dp;
}

@Override
protected Bitmap transform(BitmapPool pool, Bitmap
4000
toTransform, int outWidth, int outHeight) {
return roundCrop(pool, toTransform);
}

private static Bitmap roundCrop(BitmapPool pool, Bitmap source) {
if (source == null) return null;

Bitmap result = pool.get(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);
if (result == null) {
result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);
}

Canvas canvas = new Canvas(result);
Paint paint = new Paint();
paint.setShader(new BitmapShader(source, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
paint.setAntiAlias(true);
RectF rectF = new RectF(0f, 0f, source.getWidth(), source.getHeight());
canvas.drawRoundRect(rectF, radius, radius, paint);
return result;
}

@Override
public String getId() {
return getClass().getName() + Math.round(radius);
}

ListView中条目有大量gif显示，在快速滑动时，应显示该gif动画的静态图(第一帧动画)有助于增加用户体验。

mListView.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
switch (scrollState)
{
//滑动
case AbsListView.OnScrollListener.SCROLL_STATE_FLING:
将gif的静态图显示出来
break;
//停止
case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
恢复gif动画
break;
//滚动
case    AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:
break;
}
}

@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

}
});