我正在尝试为我的 map 集群设置一个 View 。 我正在膨胀 XML 的 View 并根据群集大小设置文本,我想显示该 View 。 在下面的代码中,我得到一个空位图作为返回:
private Bitmap createClusterBitmap(int clusterSize) {
View cluster = LayoutInflater.from(context).inflate(R.layout.map_cluster, null);
cluster.setText(String.valueOf(clusterSize));
cluster.setDrawingCacheEnabled(true);
cluster.buildDrawingCache(true);
Bitmap bm = cluster.getDrawingCache();
return bm;
}
在下面的代码中,我在第四行(布局参数)得到空指针:
private Bitmap createClusterBitmap(int clusterSize) {
View cluster = LayoutInflater.from(context).inflate(R.layout.map_cluster, null);
TextView clusterSizeText = (TextView) cluster.findViewById(R.map.cluster);
clusterSizeText.setText(String.valueOf(clusterSize));
Bitmap clusterBitmap = Bitmap.createBitmap( cluster.getLayoutParams().width, cluster.getLayoutParams().height, Bitmap.Config.ARGB_8888);
Canvas clusterCanvas = new Canvas(clusterBitmap);
cluster.layout(cluster.getLeft(), cluster.getTop(), cluster.getRight(), cluster.getBottom());
cluster.draw(clusterCanvas);
return clusterBitmap;
}
当将其更改为以下代码时,我没有收到错误消息,但未绘制任何内容:
private Bitmap createClusterBitmap(int clusterSize) {
View cluster = LayoutInflater.from(context).inflate(R.layout.map_cluster, null);
TextView clusterSizeText = (TextView) cluster.findViewById(R.map.cluster);
clusterSizeText.setText(String.valueOf(clusterSize));
Bitmap clusterBitmap = Bitmap.createBitmap( 50,50 , Bitmap.Config.ARGB_8888);
Canvas clusterCanvas = new Canvas(clusterBitmap);
cluster.layout(50, 50, 50, 50;
cluster.draw(clusterCanvas);
return clusterBitmap;
}
这是我的 XML:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+map/cluster"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/map_pointer_cluster"
android:gravity="center"
android:orientation="vertical"
android:textColor="@android:color/black"
android:textSize="35dp"
android:textStyle="bold" />
最佳答案
您的 cluster.getLayoutParams()
可能是 null
。首先,您需要测量膨胀 View 的宽度/高度,然后分配给它。如下所示:
private Bitmap createClusterBitmap(int clusterSize) {
View cluster = LayoutInflater.from(context).inflate(R.layout.map_cluster,
null);
TextView clusterSizeText = (TextView) cluster.findViewById(R.id.map_cluster_text);
clusterSizeText.setText(String.valueOf(clusterSize));
cluster.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
cluster.layout(0, 0, cluster.getMeasuredWidth(),cluster.getMeasuredHeight());
final Bitmap clusterBitmap = Bitmap.createBitmap(cluster.getMeasuredWidth(),
cluster.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(clusterBitmap);
cluster.draw(canvas);
return clusterBitmap;
}
关于android 将 XML View 转换为位图而不显示它,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12402392/