如何使用Glide将图片下载到位图中？

这个示例使用Glide将图片下载到位图中。

步骤1 - 在build.gradle中的Module: app中添加以下依赖项：

implementation 'com.github.bumptech.glide:glide:4.9.0'

步骤二 - 将以下代码添加到res/layout/activity_main.xml中。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <ImageView
      android:id="@+id/imageView"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />
</RelativeLayout>

第三步 - 将以下代码添加到src/MainActivity.java文件中。

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.ImageView;
import com.bumptech.glide.Glide;
import com.bumptech.glide.request.target.CustomTarget;
import com.bumptech.glide.request.transition.Transition;
public class MainActivity extends AppCompatActivity {
   ImageView imageView;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      imageView = findViewById(R.id.imageView);
      Glide.with(this).asBitmap().load("https://www.google.es/images/srpr/logo11w.png").into(new CustomTarget<Bitmap>() {
         @Override
         public void onResourceReady(@NonNull Bitmap resource, @Nullable Transition<? super Bitmap> transition) {
            imageView.setImageBitmap(resource);
         }
         @Override
         public void onLoadCleared(@Nullable Drawable placeholder) {
         }
      });
   }
}

第四步 - 将以下代码添加到androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <uses-permission android:name="android.permission.INTERNET"/>
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
         <activity android:name=".MainActivity">
            <intent-filter>
               <action android:name="android.intent.action.MAIN" />
               <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
         </activity>
   </application>
</manifest>

让我们尝试运行您的应用程序。

完整答案

我不得不添加 try-catch 块，因为如果 URL 无效，现在 Glide 会导致应用程序崩溃。

  return try {
            Glide.with(context)
                .asBitmap()
                .load(imageURL)
                .listener(object : RequestListener<Bitmap> {
                    override fun onLoadFailed(
                        e: GlideException?,
                        model: Any?,
                        target: Target<Bitmap>?,
                        isFirstResource: Boolean
                    ): Boolean {
                        Log.e(
                            TAG,
                            "Texture from ResourceID $resourceId could not be Loaded. " +
                                    "Using default Texture"
                        )
                        return false
                    }

                    override fun onResourceReady(
                        resource: Bitmap?,
                        model: Any?,
                        target: Target<Bitmap>?,
                        dataSource: DataSource?,
                        isFirstResource: Boolean
                    ): Boolean {
                        return false
                    }
                })
                .placeholder(DEFAULT_IMAGE)
                .error(DEFAULT_IMAGE)
                .submit()
                .get()
        } catch (ex: Exception) {
            return fromResource(DEFAULT_IMAGE)
        }

新版本:

GlideApp.with(imageView)
    .asBitmap()
    .override(200, 200)
    .centerCrop()
    .load(mUrl)
    .error(R.drawable.defaultavatar)
    .diskCacheStrategy(DiskCacheStrategy.ALL)
    .signature(ObjectKey(System.currentTimeMillis() / (1000*60*60*24))) //refresh avatar cache every day
    .into(object : CustomTarget<Bitmap>(){
        override fun onLoadCleared(placeholder: Drawable?) {}
        override fun onLoadFailed(errorDrawable: Drawable?) {
            //add context null check in case the user left the fragment when the callback returns
            context?.let { imageView.addImage(BitmapFactory.decodeResource(resources, R.drawable.defaultavatar)) }
        }
        override fun onResourceReady(
            resource: Bitmap,
            transition: Transition<in Bitmap>?) { context?.let { imageView.addImage(resource) } }
    })

Kotlin的方式 -

fun Context.bitMapFromImgUrl(imageUrl: String, callBack: (bitMap: Bitmap) -> Unit) {
    GlideApp.with(this)
        .asBitmap()
        .load(imageUrl)
        .into(object : CustomTarget<Bitmap>() {
            override fun onResourceReady(resource: Bitmap, transition: Transition<in Bitmap>?) {
                callBack(resource)
            }

            override fun onLoadCleared(placeholder: Drawable?) {
                // this is called when imageView is cleared on lifecycle call or for
                // some other reason.
                // if you are referencing the bitmap somewhere else too other than this imageView
                // clear it here as you can no longer have the bitmap
            }
        })
}

在最新版本的Glide中，我们可以做到这一点。

val bitmap = Glide.with(context)
        .asBitmap()
        .load("url")
        .submit()
        .get()