Question

我遇到了问题。

我希望动态地向TableLayout添加行。添加这些行时，我需要能够获得View的大小，因此我尝试在onSizeChanged()期间执行此操作，但不显示新行。我尝试了onFinishInflate()，但后来我无权访问(getMeasuredHeight returns 0)。

以下代码的输出显示两行initial row + onFinishInflate getMeasuredHeight=0。但是，如果我使用sdk中的hierarchyviewer并按load view hierarchy，那么我会突然在模拟器initial row + onFinishInflate getMeasuredHeight=0 + onSizeChanged getMeasuredHeight=270中看到3行！

注意：这是使用模拟器2.1 hvga landscape，内置代码最新的sdk，目标是android1.5。

<?xml version="1.0" encoding="utf-8"?>
<com.steelbytes.android.TableHeightTest.TestLinLay 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <TableLayout
        android:id="@+id/table1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        >
        <TableRow
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                >
                <TextView
                    android:text="initial row"
                />
            </TableRow>
        </TableLayout>
</com.steelbytes.android.TableHeightTest.TestLinLay>

package com.steelbytes.android.TableHeightTest;

import android.app.Activity;
import android.os.Bundle;

public class TableHeightTest extends Activity
{
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

package com.steelbytes.android.TableHeightTest;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.LinearLayout;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;

public class TestLinLay extends LinearLayout
{
 Context mContext;

 public TestLinLay(Context context, AttributeSet attrs)
 {
  super(context, attrs);
  mContext = context;
 }

    private void addRow(String funcName)
    {
        TableLayout tl = (TableLayout)findViewById(R.id.table1);
        TableRow tr = new TableRow(mContext);
        TextView tv = new TextView(mContext);
        tv.setText(funcName+" getMeasuredHeight="+tl.getMeasuredHeight());
        tr.addView(tv);
        tl.addView(tr);
    }

    @Override
    protected void onFinishInflate()
    {
        super.onFinishInflate();
        addRow("onFinishInflate");
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh)
    {
        super.onSizeChanged(w,h,oldw,oldh);
        addRow("onSizeChanged");
    }
}

Answer 1

在调用getMeasuredWidth / getMeasuredHeight之前，通过调用View.measure（int widthMeasureSpec，int heightMeasureSpec）（http://developer.android.com/reference/android/view/View.html#measure%28int,%20int%29）可以很好地获得测量高度。

Answer 2

我遇到了同样的问题。最终我偶然发现了以下“规则”：你不能/不应该在“布局传递”（onSizeChanged（））期间requestLayout（），正确的方法是“发布一个Runnable”以便稍后执行。这是我在onSizeChanged（）覆盖完成时使用的代码（我调整了所有按钮的大小）

// Note: 'posting a Runnable' is required to call requestLayout(),
// not supposed to call requestLayout() during a 
// layout pass (onSizeChanged())
private Handler handler;        // for posting request(s)

(In constructor code)
{
    handler = new Handler();
}

/*
 * Post request to run a loop requesting button layout so
 * the buttons will be drawn using their new size.
 */
private void postLayoutRequest() {
handler.post(new Runnable() {
    @Override public void run() {
    for(int i = BTN_BASE_ID; i <= TOP_BUTTON_ID; ++i) {
            ButtonEx btn = (ButtonEx)findViewById(i);
            btn.requestLayout();
        }
    }
});
}

添加TableRow与getMeasuredHeight / getHeight的问题

2 个答案: