滚动到TableLayout的滚动型中的最后一行TableLayout

2023-09-06 02:02:22 作者：只想独占沵的①切

我想有一个动态表，添加了随着时间的推移用户交互的结果行，使用TableLayout内的滚动型。这工作得很好，但是当我想用滚动到表的末尾fullScroll(),它总是让出最后一行;也就是说，它滚动，使得前的最后一个是可见的。手动滚动时的最后一行是可见的，并且滚动条是正确的了。

I want to have a dynamic table, with rows added over time as a result of user interaction, using a TableLayout inside a ScrollView. This works fine, but when I want to scroll to the end of the table using fullScroll(), it always leaves out the last line; that is, it scrolls so that the one before the last one is visible. The last line is visible when scrolling manually, and the scrollbar is correct too.

我当然愿意听取建议的，如何做一个更好的布局出了这一点;但我理解为什么 fullScroll（）的行为这种方式特别感兴趣。我应该给它一个不同的参数，或者用别的东西完全？或者它这样做，因为新添加的行尚未出现不知何故？（如果是这样，我怎么能解决呢？）还是我错过了一些其他的显而易见的事？

I'm of course open to suggestions as to how to make a better layout out of this; but I'm specifically interested in understanding why fullScroll() behaves that way. Should I give it a different parameter, or use something else altogether? Or does it do that because the newly added line isn't yet visible somehow? (if so, how can I solve that?) Or did I miss some other obvious thing?

下面code复制问题：

The following code replicates the problem:

TestActivity.java：

TestActivity.java:

package com.example.android.tests;

import java.util.Random;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ScrollView;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;

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

        ((Button) findViewById(R.id.AddRow)).setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Random rnd = new Random();
                TableRow nr = new TableRow(v.getContext());
                for (int c=0; c<3; c++) {
                    TextView nv = new TextView(v.getContext());
                    nv.setText(Integer.toString(rnd.nextInt(20)-10)); 
                    nr.addView(nv);
                }
                ((TableLayout) findViewById(R.id.Table)).addView(nr);
                // Scrolls to line before last - why?
                ((ScrollView) findViewById(R.id.TableScroller)).fullScroll(View.FOCUS_DOWN);
            }
        });

    }
}

main.xml中：

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">
  <Button
    android:text="Add Row"
    android:id="@+id/AddRow"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true" />
  <ScrollView
    android:id="@+id/TableScroller"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_above="@id/AddRow"
    android:layout_alignParentTop="true" >
    <TableLayout
      android:id="@+id/Table"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:stretchColumns="0,1,2" />
  </ScrollView>
</RelativeLayout>

编辑：仅供参考，我实现了罗曼盖伊的解决方案如下：

for reference, I implemented Romain Guy's solution as follows:

在TestActivity.java，替换：

In TestActivity.java, replace:

            // Scrolls to line before last - why?
            ((ScrollView) findViewById(R.id.TableScroller)).fullScroll(View.FOCUS_DOWN);

与

            // Enqueue the scrolling to happen after the new row has been layout
            ((ScrollView) findViewById(R.id.TableScroller)).post(new Runnable() {
                public void run() {
                    ((ScrollView) findViewById(R.id.TableScroller)).fullScroll(View.FOCUS_DOWN);
                }

            });

，工作正常。

Which works fine.

滚动到TableLayout的滚动型中的最后一行TableLayout

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