判断ListView的每一个item高度

前提 这个item的根view必须是LinearLayout

package com.bxg.news.view;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.ListView;

public class Utility {
public static void setListViewHeightBasedOnChildren(ListView listView,
View v) {
// 获取ListView对应的Adapter
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) {
// pre-condition
return;
}

int totalHeight = 0;
for (int i = 0, len = listAdapter.getCount(); i < len; i++) { // listAdapter.getCount()返回数据项的数目
View listItem = listAdapter.getView(i, null, listView);
listItem.measure(0, 0); // 计算子项View 的宽高
totalHeight += listItem.getMeasuredHeight(); // 统计所有子项的总高度
}

if (v != null) {
totalHeight += v.getHeight();
}

ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight
+ (listView.getDividerHeight() * (listAdapter.getCount() - 1))
+ 10;
// listView.getDividerHeight()获取子项间分隔符占用的高度
// params.height最后得到整个ListView完整显示需要的高度
listView.setLayoutParams(params);
}
}

这里需要注意的是：

如果TextView是多行的时候。需要对TextView进行重写onmeasure方法

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);

Layout layout = getLayout();
if (layout != null) {
int height = (int) FloatMath.ceil(getMaxLineHeight(this.getText()
.toString()))
+ getCompoundPaddingTop()
+ getCompoundPaddingBottom();
int width = getMeasuredWidth();
setMeasuredDimension(width, height);
}
}

private float getMaxLineHeight(String str) {
float height = 0.0f;
float screenW = ((Activity) context).getWindowManager()
.getDefaultDisplay().getWidth();
float paddingLeft = ((RelativeLayout) this.getParent())
.getPaddingLeft();
float paddingReft = ((RelativeLayout) this.getParent())
.getPaddingRight();
// 这里具体this.getPaint()要注意使用，要看你的TextView在什么位置，这个是拿TextView父控件的Padding的，为了更准确的算出换行
int line = (int) Math.ceil((this.getPaint().measureText(str) / (screenW
- paddingLeft - paddingReft)));
height = (this.getPaint().getFontMetrics().descent - this.getPaint()
.getFontMetrics().ascent) * line;
return height;
}

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