Android ImageView: 适配宽度

I think you cant do it only with XML, you need to resize yourself, the bitmap

Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();


try {
((ImageView) findViewById(R.id.background))
.setImageBitmap(ShrinkBitmap(width));
} catch (FileNotFoundException e) {
e.printStackTrace();
}

then

private Bitmap ShrinkBitmap(int width)
throws FileNotFoundException {


BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
bmpFactoryOptions.inJustDecodeBounds = true;
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.img, bmpFactoryOptions);
int widthRatio = (int) android.util.FloatMath
.ceil(bmpFactoryOptions.outWidth / (float) width);




bmpFactoryOptions.inSampleSize = widthRatio;






if (bmpFactoryOptions.inSampleSize <= 0)
bmpFactoryOptions.inSampleSize = 0;
bmpFactoryOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;
bmpFactoryOptions.inJustDecodeBounds = false;
bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.img, bmpFactoryOptions);
return bitmap;


}

And the layout

 <ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/background"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>

This elegant solution found here will work like a charm for you.

Basically you just have to create a small class that extends ImageView and simply override the onMeasure method to adjust the width and height as you want. Here it scales to fit width by using:

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = width * getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth();
setMeasuredDimension(width, height);
}

You would use this special ImageView like this:

<your.activity.package.AspectRatioImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_vertical"
android:src="@drawable/test" />

I ended up using this code:

<ImageView
android:id="@+id/background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="centerCrop"
android:src="@drawable/name"
/>

Make sure you set the image using src instead of background.

There is a simple method if you simply want to fill the width of screen and have height proportional (and know the ratio of the image) you can do this in OnCreate():

setContentView(R.layout.truppview_activity);
trupImage = (ImageView) findViewById(R.id.trupImage);


Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics();
display.getMetrics(outMetrics);
float scWidth = outMetrics.widthPixels;
trupImage.getLayoutParams().width = (int) scWidth;
trupImage.getLayoutParams().height = (int) (scWidth * 0.6f);

Where 0.6 is the ratio adjustment (you could also calc automatically of course if you know the w & h of image).

PS:
Here is the XML side:

  <ImageView
android:id="@+id/trupImage"
android:layout_width="match_parent"
android:background="@color/orange"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="fitCenter" />

android:adjustViewBounds="true" does the job!

This works for me.

Create a class extends ImageView

    package com.yourdomain.utils;


import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;


public class ResizableImageView extends ImageView {


public ResizableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}


@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable d = getDrawable();


if (d != null) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = (int) Math.ceil((float) width * (float) d.getIntrinsicHeight() / (float) d.getIntrinsicWidth());
setMeasuredDimension(width, height);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}

In xml use the following instead of ImageView

    <com.yourdomain.utils.ResizableImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="@drawable/test" />

if you want to fit the image whole parent block
it will stretch the image

        android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"

And if you want to fit image whole parent with original ratio of image
it will crop out some part of image

        android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="centerCrop"