Question

我已经从网址下载了一个位图，现在我希望将其设置为我的相对布局的背景。这是我的代码

Bitmap bitmap = null;
     WebClient client = new WebClient ();
     client.DownloadDataAsync (new Uri (mItems [position].Profile_Pic));
     client.DownloadDataCompleted += (se, res) => {
      bitmap = BitmapFactory.DecodeByteArray (res.Result, 0, res.Result.Length);
      var relativelayout=row.FindViewById<RelativeLayout>(Resource.Id.relativeLayout1);

我该如何去做？感谢您的帮助

Answer 1

您应该使用BitmapDrawable

var bitmapDrawable = new BitmapDrawable(bitmap);

...

relativelayout.SetBackground(bitmapDrawable);
//or
relativelayout.SetBackgroundDrawable(bitmapDrawable);
//SetBackgroundDrawable deprecated in API level 16

Answer 2

Android的方式是：

 relativelayout.setBackground(...);

表示int资源，或

 relativelayout.setBackgroundResource(...);

为drawable。

我确定你能找到符合Xamarin的方法

Answer 3

Just add a ImageView in your relativeLayout and get an instance of your imageView and try this :-

In your axml file :
<RelativeLayout
    android:id="@+id/relativeLayout1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
<ImageView
            android:id="@+id/img"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:visibility="visible"
            android:fitsSystemWindows="true"
            android:adjustViewBounds="true"
            android:scaleType="matrix"
            android:background="@drawable/image_placeholder"
            android:padding="3dp" />
</RelativeLayout>

In Code:

var imageView =row.FindViewById<ImageView>(Resource.Id.img);
**img.SetImageBitmap(bitmap);**

Answer 4

请尝试一次。

BitmapDrawable background = new BitmapDrawable(YOUR_BITMAP_SOURCE);
YOUR_LAYOUT.setBackground(background);

如何在相对布局背景中设置位图图像

4 个答案: