Question

我搜索了很多针对与我类似但不相同的问题的解决方案。

我必须显示存储在服务器（互联网）上的jpg文件（作为广告横幅不是全屏）。我尝试过使用WebView，但是，当屏幕宽度大于图像宽度时，图像看起来比屏幕小。

是否可以使用ImageView而不是WebView？如果“是”，我如何缩放下载的图像以适应不同的屏幕分辨率？

提前致谢。

此解决方案找到https://stackoverflow.com/a/9288544/2252143：

MainActivity.java：

public class MainActivity extends Activity {

    ImageView imgProva = null;
    FunzioniUtili Funzioni = new FunzioniUtili();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imgProva = (ImageView)findViewById(R.id.imgProva);

        // show The Image
        new DownloadImageTask((ImageView) findViewById(R.id.imgProva)).execute("http://www.softlive.net/advs/banner_adolfo.jpg");
    }

    public void onClick(View v) {
        startActivity(new Intent(this, MainActivity.class));
        finish();

}

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    ImageView bmImage;

    public DownloadImageTask(ImageView bmImage) {
        this.bmImage = bmImage;
    }

    protected Bitmap doInBackground(String... urls) {
        String urldisplay = urls[0];
        Bitmap mIcon11 = null;
        try {
            InputStream in = new java.net.URL(urldisplay).openStream();
            mIcon11 = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return mIcon11;
    }

    protected void onPostExecute(Bitmap result) {
        bmImage.setImageBitmap(result);
        int DisplayWidth = 0;
        DisplayWidth  = Funzioni.ScreenWidth (MainActivity.this);

        double CardResizeFactor=1.0;
        //This is the function that I use to resize... / CardResizer is redundant, I know!
        Funzioni.scaleImage(bmImage,(int)(DisplayWidth / CardResizeFactor),0,0);
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

我的调整大小功能：

/**
 * public void scaleImage(ImageView view, int boundBoxInDp)
 * 
 * Resize the given ImageView.
 *
 * @param view The ImageView.
 * @param boundBoxInDp   Scaling factor in Dp.
 * @param layoutType 0 = RelativeLayout 1 = LinearLayout 2 = TableLayout 3 = TableRow 4 = FrameLayout.
 * @param colNumber Column number if the selected layout is TableRow. If other, put 0
 */
public void scaleImage(ImageView view, int boundBoxInDp, int layoutType, int colNumber)
{
    // Get the ImageView and its bitmap
    Drawable drawing = view.getDrawable();
    Bitmap bitmap = ((BitmapDrawable)drawing).getBitmap();

    // Get current dimensions
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();

    // Determine how much to scale: the dimension requiring less scaling is
    // closer to the its side. This way the image always stays inside your
    // bounding box AND either x/y axis touches it.
    float xScale = ((float) boundBoxInDp) / width;
    float yScale = ((float) boundBoxInDp) / height;
    float scale = (xScale <= yScale) ? xScale : yScale;

    // Create a matrix for the scaling and add the scaling data
    Matrix matrix = new Matrix();
    matrix.postScale(scale, scale);

    // Create a new bitmap and convert it to a format understood by the ImageView
    Bitmap scaledBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
    BitmapDrawable result = new BitmapDrawable(scaledBitmap);
    width = scaledBitmap.getWidth();
    height = scaledBitmap.getHeight();

    // Apply the scaled bitmap
    view.setImageDrawable(result);

    // Now change ImageView's dimensions to match the scaled image
    if(layoutType == 0)
    {
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) view.getLayoutParams();
        params.width = width;
        params.height = height;

        view.setLayoutParams(params);
    }
    else if(layoutType == 1)
    {
        LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) view.getLayoutParams();
        params.width = width;
        params.height = height;
        view.setLayoutParams(params);
    }
    else if(layoutType == 2)
    {
        TableLayout.LayoutParams params = (TableLayout.LayoutParams) view.getLayoutParams();

        params.width = width;
        params.height = height;
        view.setLayoutParams(params);
    }
    else if(layoutType == 3)
    {
        TableRow.LayoutParams params = (TableRow.LayoutParams) view.getLayoutParams();
        params.width = width;
        params.height = height;
        params.column = colNumber;
    }
    else if(layoutType == 4)
    {
        FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) view.getLayoutParams();
        params.width = width;
        params.height = height;
        view.setLayoutParams(params);
    }
}

这是我的Activity_Main.xml：

<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" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <ImageView
        android:id="@+id/imgProva"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:src="@drawable/ic_launcher" />

</RelativeLayout>

Answer 1

您可以使用css

将图像的宽度设置为100％

见 http://www.w3schools.com/cssref/pr_dim_width.asp

Answer 2

我用它来显示png图像。它将拉伸图像以垂直填充屏幕，保持其纵横比。它似乎只适用于API 11+。它在RelativeLayout中。

<ImageView
    android:id="@+id/main_imageView"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:src="@drawable/img_alchemy2" />

Answer 3

好的，我找到了解决方案，并且我编辑了添加代码的问题。感谢。

ImageView或WebView ......就是这样

3 个答案: