我有以下问题，我的应用程序在线检索数据库中的数据以及文本，还有我通过以下类查看的图像。图像显示正确但不是它们的大小，我想根据显示器的大小调整大小，你知道我该怎么办？来源是：
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.text.Html.ImageGetter;
class HttpImageGetter implements ImageGetter {
@Override
public Drawable getDrawable(String source) {
try {
URL url = new URL(source);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
BitmapDrawable dr = new BitmapDrawable(BitmapFactory.decodeStream(is));
dr.setBounds(0, 0, dr.getIntrinsicWidth(), dr.getIntrinsicHeight());
return dr;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}
我还有第二个问题。文本的打开速度较慢，因为如果再次单击文本名称显示屏幕全黑，有些图像的重量会更多，有时它表示应用程序没有响应。所有这些都发生在我与Edge连接时。您是否有关于如何修复和加快文本开头的想法？
PS：图像包含在TextView
中答案 0 :(得分：0)
private TextView htmlTextView;
private SpannableStringBuilder htmlSpannable;
@Override
public void onCreate(Bundle savedInstanceState) {
// ...
// first parse the html
// replace getHtmlCode() with whatever generates/fetches your html
Spanned spanned = Html.fromHtml(getHtmlCode());
// we need a SpannableStringBuilder for later use
if (spanned instanceof SpannableStringBuilder) {
// for now Html.fromHtml() returns a SpannableStringBuiler
// so we can just cast it
htmlSpannable = (SpannableStringBuilder) spanned;
} else {
// but we have a fallback just in case this will change later
// or a custom subclass of Html is used
new SpannableStringBuilder(spanned);
}
// now we can call setText() on the next view.
// this won't show any images yet
htmlTextView.setText(htmlSpannable);
// next we start a AsyncTask that loads the images
new ImageLoadTask().execute();
// ...
}
private class ImageLoadTask extends AsyncTask {
DisplayMetrics metrics = new DisplayMetrics();
@Override
protected void onPreExecute() {
// we need this to properly scale the images later
getWindowManager().getDefaultDisplay().getMetrics(metrics);
}
@Override
protected Void doInBackground(Void... params) {
// iterate over all images found in the html
for (ImageSpan img : htmlSpannable.getSpans(0,
htmlSpannable.length(), ImageSpan.class)) {
if (!getImageFile(img).isFile()) {
// here you have to download the file
}
// we use publishProgress to run some code on the
// UI thread to actually show the image
// -> onProgressUpdate()
publishProgress(img);
}
return null;
}
@Override
protected void onProgressUpdate(ImageSpan... values) {
// save ImageSpan to a local variable just for convenience
ImageSpan img = values[0];
// now we get the File object again. so remeber to always return
// the same file for the same ImageSpan object
File cache = getImageFile(img);
// if the file exists, show it
if (cache.isFile()) {
// first we need to get a Drawable object
Drawable d = new BitmapDrawable(getResources(),
cache.getAbsolutePath());
// next we do some scaling
int width, height;
int originalWidthScaled = (int) (d.getIntrinsicWidth() * metrics.density);
int originalHeightScaled = (int) (d.getIntrinsicHeight() * metrics.density);
if (originalWidthScaled > metrics.widthPixels) {
height = d.getIntrinsicHeight() * metrics.widthPixels
/ d.getIntrinsicWidth();
width = metrics.widthPixels;
} else {
height = originalHeightScaled;
width = originalWidthScaled;
}
// it's important to call setBounds otherwise the image will
// have a size of 0px * 0px and won't show at all
d.setBounds(0, 0, width, height);
// now we create a new ImageSpan
ImageSpan newImg = new ImageSpan(d, img.getSource());
// find the position of the old ImageSpan
int start = htmlSpannable.getSpanStart(img);
int end = htmlSpannable.getSpanEnd(img);
// remove the old ImageSpan
htmlSpannable.removeSpan(img);
// add the new ImageSpan
htmlSpannable.setSpan(newImg, start, end,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
// finally we have to update the TextView with our
// updates Spannable to display the image
htmlTextView.setText(htmlSpannable);
}
}
private File getImageFile(ImageSpan img) {
// you need to implement this method yourself.
// it must return a unique File object (or something
// different if you also change the rest of the code)
// for every image tag. use img.getSource() to get
// the src="" attribute. you might want to use some
// hash of the url as file name
}
}
调整图像大小所包含的代码是您可以根据需要更改逻辑20缩放％或任何您想要的显示基质（屏幕的高度和宽度）享受
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int width, height;
int originalWidthScaled = (int) (d.getIntrinsicWidth() * metrics.density);
int originalHeightScaled = (int) (d.getIntrinsicHeight() * metrics.density);
if (originalWidthScaled > metrics.widthPixels) {
height = d.getIntrinsicHeight() * metrics.widthPixels
/ d.getIntrinsicWidth();
width = metrics.widthPixels;
} else {
height = originalHeightScaled;
width = originalWidthScaled;
}
// it's important to call setBounds otherwise the image will
// have a size of 0px * 0px and won't show at all
d.setBounds(0, 0, width, height);
并在seprate线程中加载图像将避免使用