How can I get an Android TableLayout to fill the screen?

问题

I'm battling with Android's awful layout system. I'm trying to get a table to fill the screen (simple right?) but it's ridiculously hard.

I got it to work somehow in XML like this:

<?xml version="1.0" encoding="utf-8"?>

<TableLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_height="fill_parent" android:layout_width="fill_parent">
<TableRow android:layout_height="fill_parent" android:layout_width="fill_parent" android:layout_weight="1">
<Button android:text="A" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_weight="1"/>
<Button android:text="B" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_weight="1"/>
</TableRow>
<TableRow android:layout_height="fill_parent" android:layout_width="fill_parent" android:layout_weight="1">
<Button android:text="C" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_weight="1"/>
<Button android:text="D" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_weight="1"/>
</TableRow>

However I can not get it to work in Java. I've tried a million combinations of the LayoutParams, but nothing ever works. This is the best result I have which only fills the width of the screen, not the height:

    table = new TableLayout(this);
    // Java. You suck.
    TableLayout.LayoutParams lp = new TableLayout.LayoutParams(
                                    ViewGroup.LayoutParams.FILL_PARENT,
                                    ViewGroup.LayoutParams.FILL_PARENT);
    table.setLayoutParams(lp); // This line has no effect! WHYYYY?!
    table.setStretchAllColumns(true);
    for (int r = 0; r < 2; ++r)
    {
        TableRow row = new TableRow(this);
        for (int c = 0; c < 2; ++c)
        {
            Button btn = new Button(this);
            btn.setText("A");
            row.addView(btn);
        }
        table.addView(row);
    }

Obviously the Android documentation is no help. Anyone have any ideas?

回答1:

There are two mistakes in the above discussion.

It is possible to programatically set the weight by specifying TableLayout.LayoutParams and TableRow.LayoutParams and using the appropriate constructor, e.g.
```
TableLayout.LayoutParams rowInTableLp = new TableLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT, 1.0f);
```
A widget must have the LayoutParams of its parent. Therefore, the rows must use TableLayout.LayoutParams.

This gives you the following working version of your initial code:

TableLayout table = new TableLayout(this);
// Java. You succeed!
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(
        ViewGroup.LayoutParams.FILL_PARENT,
        ViewGroup.LayoutParams.FILL_PARENT);
table.setLayoutParams(lp);
table.setStretchAllColumns(true);

TableLayout.LayoutParams rowLp = new TableLayout.LayoutParams(
        ViewGroup.LayoutParams.FILL_PARENT,
        ViewGroup.LayoutParams.FILL_PARENT,
        1.0f);
TableRow.LayoutParams cellLp = new TableRow.LayoutParams(
        ViewGroup.LayoutParams.FILL_PARENT,
        ViewGroup.LayoutParams.FILL_PARENT,
        1.0f);
for (int r = 0; r < 2; ++r)
{
    TableRow row = new TableRow(this);
    for (int c = 0; c < 2; ++c)
    {
        Button btn = new Button(this);
        btn.setText("A");
        row.addView(btn, cellLp);
    }
    table.addView(row, rowLp);
}
setContentView(table);

Thanks to Romain Guy's comment on Android developer's forum for the solution.

回答2:

Finally worked out how to do this. Gave up on TableLayout and just used horizontal LinearLayouts inside a vertical one. The critical key is to set the weight. If you specify FILL_PARENT but with the default weight, it doesn't work:

LinearLayout buttonsView = new LinearLayout(this);
buttonsView.setOrientation(LinearLayout.VERTICAL);
for (int r = 0; r < 6; ++r)
{
    LinearLayout row = new LinearLayout(this);
    row.setOrientation(LinearLayout.HORIZONTAL);
    for (int c = 0; c < 4; ++c)
    {
        Button btn = new Button(this);
        btn.setText("A");
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.FILL_PARENT);
        lp.weight = 1.0f;
        row.addView(btn, lp);
    }
    LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.FILL_PARENT);
    lp.weight = 1.0f;
    buttonsView.addView(row, lp);
}  

ViewGroup.LayoutParams lp = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT);
setContentView(buttonsView, lp);

回答3:

Found the answer: apparently it is the layout_weight that makes it work and there is no way to set it from Java. Damnit.

See How can I get an Android TableLayout to fill the parent in landscape mode?

回答4:

You never set the row or button layout parameters whereas in the posted xml you do that..change the details of the for loops to set both the row layout parameters and the button layout parameters than it should give the same result as your xml.

回答5:

To set TableLayout LayoutParams, we logically expect to use TableLayout.LayoutParams class, but you will get a cast error stating that TableLayout.LayoutParams cannot be casted into FrameLayout.LayoutParams.

So, you should use FrameLayout.LayoutParams, if you want to programmatically set TableLayout properties. For example:

FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(TableLayout.LayoutParams.MATCH_PARENT,TableLayout.LayoutParams.MATCH_PARENT);
            layoutParams.setMargins(80, 0, 0, 0);
            TableLayout tableLayout = (TableLayout) findViewById(R.id.header_detail);
            tableLayout.setLayoutParams(layoutParams);

来源：https://stackoverflow.com/questions/2393847/how-can-i-get-an-android-tablelayout-to-fill-the-screen

标签

java

xml

android

layout

tablelayout