从URL总是空的Android位图

本文介绍了从URL总是空的Android位图的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我想从URL下载图像，并将其转换成位图，但行

I'm trying to download an image from a URL and convert it into a bitmap, but the line

Bitmap myBitmap = BitmapFactory.decodeStream(input);

总是导致调试器跳到下面的行

always causes the debugger to skip to the following line

return null;

，却从来没有打印出堆栈跟踪和异常变量也不会在调试器中列出的变量存在。我读了很多关于如何有可能是使用URL实际上并不导致图像，没有得到很好的格式化图像等问题，但它仍然与我敢肯定存在一个硬codeD映像相同的问题。

without ever actually printing out the stack trace and the Exception variable also doesn't exist in the variables listed in the Debugger. I read a lot about how there might be issues with urls not actually leading to images, not well formated images and the like but it still has the same issue with a hardcoded image that I'm positive exists.

public static Bitmap getBitmapFromURL(String src) {
    try {
        URL url = new URL(
                "http://www.helpinghomelesscats.com/images/cat1.jpg");
        HttpURLConnection connection = (HttpURLConnection) url
                .openConnection();
        connection.setDoInput(true);
        connection.connect();
        InputStream input = connection.getInputStream();
        Bitmap myBitmap = BitmapFactory.decodeStream(input);
        return myBitmap;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}

因为它看起来可能涉及的manifest.xml文件我已经编辑在这里添加。

Since it seems like the manifest.xml file might be involved I've edited to add here.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.delivery"
android:versionCode="1"
android:versionName="1.0">

<uses-permission android:name="android.permission.CALL_PHONE"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".IntroPage"
              android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".Browse"></activity>
    <activity android:name=".ViewProduct"></activity>
    <activity android:name=".ViewOrder"></activity>
    <activity android:name=".GetAddress"></activity>
    <activity android:name=".ConfirmOrder"></activity>
</application>

推荐答案

以下为所有类型的图像code的工作。

following code work for all type of images.

    try {

        URL url = new URL("http://www.helpinghomelesscats.com/images/cat1.jpg");
        InputStream in = url.openConnection().getInputStream();
        BufferedInputStream bis = new BufferedInputStream(in,1024*8);
        ByteArrayOutputStream out = new ByteArrayOutputStream();

        int len=0;
        byte[] buffer = new byte[1024];
        while((len = bis.read(buffer)) != -1){
            out.write(buffer, 0, len);
        }
        out.close();
        bis.close();

        byte[] data = out.toByteArray();
        Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
        imageView.setImageBitmap(bitmap);
    }
    catch (IOException e) {
        e.printStackTrace();
    }

这篇关于从URL总是空的Android位图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

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