java - 无法通过 Java 在 XML 资源文件中复制布局外观

Question

我是 Android 开发新手。我在网上搜索答案，但一无所获。我正在尝试在 TableLayout 中动态创建行，如下所示:

<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main"
    tools:context="com.example.me.testdesign.MainActivity">

    <TableLayout
        android:id="@+id/tableLayout"
        android:layout_width="368dp"
        android:layout_height="345dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

            <TextView
                android:id="@+id/textView10"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="3"
                android:background="#12dd12"
                android:text="static textview"
                android:textSize="12sp"
                android:layout_marginRight="10dp"/>

            <Button
                android:id="@+id/button8"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="2"
                android:text="static btn"
                android:textSize="12sp"
                android:background="#12dd12"/>
        </TableRow>
    </TableLayout>

</android.support.constraint.ConstraintLayout>

这个 XML 文件给出了我想要的每一行的外观，如下面的快照所示:

下面是动态创建附加行的 Java 代码:

    public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
            fab.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                            .setAction("Action", null).show(); }
            });

        TableLayout.LayoutParams tvlparams =
                new TableLayout.LayoutParams(0, TableLayout.LayoutParams.MATCH_PARENT);
        tvlparams.weight = 3;
        TextView tv = new TextView(this);
        tv.setBackgroundColor(0xff12dd12);
        tv.setText("dynamic textview");
        tv.setLayoutParams(tvlparams);

        TableLayout.LayoutParams btnlparams =
                new TableLayout.LayoutParams( 0, TableLayout.LayoutParams.MATCH_PARENT);
        btnlparams.weight = 2;
        btnlparams.rightMargin = 10;
        Button btn = new Button(this);
        btn.setText("dynamic btn");
        btn.setBackgroundColor(0xff12dd12);
        btn.setLayoutParams(btnlparams);

        TableRow row = new TableRow(this);
        row.addView(tv);
        row.addView(btn);
        TableLayout TL = (TableLayout) findViewById(R.id.tableLayout);
        TL.addView(row);
    }
}

上面的Java代码似乎什么也没做!为什么我没有获得新行？

但是，如果我注释掉 tv.setLayoutParams(tvlparams) 和 btn.setLayoutParams(btnlparams) 我会得到:

这是怎么回事？我究竟做错了什么？谢谢。

Answer 1

这应该适合你:

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        /* create textview */
        TextView tv = new TextView(this);
        tv.setBackgroundColor(0xff12dd12);
        tv.setText("dynamic textview");

        /* create button */
        Button btn = new Button(this);
        btn.setText("dynamic btn");
        btn.setBackgroundColor(0xff12dd12);

        TableRow.LayoutParams trparams = new TableRow.LayoutParams(0, TableRow.LayoutParams.MATCH_PARENT);
        trparams.weight = 3;
        tv.setLayoutParams(trparams);
        trparams.weight = 2;
        trparams.rightMargin = 10;
        btn.setLayoutParams(trparams);

        TableLayout tableLayout = (TableLayout) findViewById(R.id.layoutTable);

        LinearLayout.LayoutParams tableRowParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);

        /* create a table row */
        TableRow tableRow = new TableRow(this);
        tableRow.setLayoutParams(tableRowParams);

        /* add views to the row */
        tableRow.addView(tv);
        tableRow.addView(btn);

        /* add the row to the table */
        tableLayout.addView(tableRow);
    }