Android实现ListView异步加载图片

核心提示：Message message = handler.obtainMessage(0, drawable);handler.sendMessage(message);}}.start();return null;}public static Drawable loadImageFromUrl(String url) {U

Message message = handler.obtainMessage(0, drawable);

handler.sendMessage(message);

}

}.start();

return null;

}

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 interface ImageCallback {

public void imageLoaded(Drawable imageDrawable, String imageUrl);

}

}

以上代码是实现异步获取图片的主方法，SoftReference是软引用，是为了更好的为了系统回收变量，重复的URL直接返回已有的资源，实现回调函数，让数据成功后，更新到UI线程。

几个辅助类文件：

Java代码

package cn.wangmeng.test;

public class ImageAndText {

private String imageUrl;

private String text;

public ImageAndText(String imageUrl, String text) {

this.imageUrl = imageUrl;

this.text = text;

}

public String getImageUrl() {

return imageUrl;

}

public String getText() {

return text;

}

}

package cn.wangmeng.test;

public class ImageAndText {

private String imageUrl;

private String text;

public ImageAndText(String imageUrl, String text) {

this.imageUrl = imageUrl;

this.text = text;

}

public String getImageUrl() {

return imageUrl;

}

public String getText() {

return text;

}

}

Java代码

package cn.wangmeng.test;