根据位图设置FrameLayout的高度和宽度

Question

我试图根据a设置FrameLayout宽度和高度Bitmap,我在下面做了什么

        Bitmap theBitmap = BitmapFactory.decodeFile(theFileImage.toString());
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(theBitmap.getWidth(), theBitmap.getHeight());
        frame.setLayoutParams(lp);
        image.setLayoutParams(lp);
        image.setImageBitmap(theBitmap);

但是我得到了一个ClassCastException.

我做错了什么？

编辑:

java.lang.ClassCastException: android.widget.LinearLayout$LayoutParams cannot be cast to android.widget.RelativeLayout$LayoutParams

Answer 1

要设置布局参数,您需要使用其父级的内部类LayoutParams.

例如:如果在RelativeLayout中有一个LinearLayout,并且如果需要设置Linear Layout的布局参数,则需要使用RelativeLayout的LayoutParams内部类.否则它会产生ClassCastException.

因此,在您的情况下,要设置FrameLayout的Layoutparams,您需要使用其父布局的布局参数.假设你的布局是这样的:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<FrameLayout
    android:id="@+id/flContainer"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/image"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
</FrameLayout>

</RelativeLayout>

代码:

    FrameLayout frame=(FrameLayout) findViewById(R.id.flContainer);  
    ImageView image=(ImageView) findViewById(R.id.image);
    Bitmap theBitmap = BitmapFactory.decodeFile(theFileImage.toString());
    RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(theBitmap.getWidth(), theBitmap.getHeight());
    frame.setLayoutParams(lp);
    image.setImageBitmap(theBitmap);