如何以编程方式设计此布局？答案

【问题标题】：How can I design this layout programmatically?如何以编程方式设计此布局？
【发布时间】：2014-01-23 05:40:20
【问题描述】：

我有一个父线性布局。

我需要在屏幕底部放置三个水平对齐的按钮，而不是通过 XML，而是通过 Java 代码。
按钮 1 应位于屏幕左侧
按钮 2 应位于屏幕底部
按钮 3 应该在屏幕右侧

这是需要设计的布局：

我的理解是我必须向我的父布局添加一个相对布局。还有一些按钮规则。

这是我尝试过的

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    l=(LinearLayout)findViewById(R.id.mainl);
    rl=new RelativeLayout(this);
    b1=new Button(this);
    b2=new Button(this);
    b3=new Button(this);
    b1.setText("Button 1");
    b2.setText("Button 2");
    b3.setText("Button 3");
    rl.setLayoutParams(new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT));
    RelativeLayout.LayoutParams lay = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.WRAP_CONTENT, 
            RelativeLayout.LayoutParams.WRAP_CONTENT);
    lay.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);

    rl.addView(b1);
    rl.addView(b2);
    rl.addView(b3);

    l.addView(rl);

}

而且按钮也没有出现在底部。它们出现在屏幕顶部。

Activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/mainl"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
</LinearLayout>

【问题讨论】：

标签： android android-layout android-relativelayout

【解决方案1】：

要将按钮添加到 RelativeLayout 运行时，您必须传递参数值。

尝试在左侧放置按钮b1：

RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
rl.addView(b1, params);

【讨论】：

【解决方案2】：

RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

    params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
    rl.addView(b1, params);


    RelativeLayout.LayoutParams params1 = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    params1.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE);
    rl.addView(b3, params1);

    RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams
            ( (int) LayoutParams.WRAP_CONTENT, (int) LayoutParams.WRAP_CONTENT);

    params2.addRule(RelativeLayout.CENTER_HORIZONTAL);
    rl.addView(b2, params2);



LinearLayout.LayoutParams layoutParams =
                (RelativeLayout.LayoutParams) txt1.getLayoutParams();
    layoutParams.addRule(LinearLayout.BOTTOM, 1);

rl.setLayoutParams(layoutParams);

【讨论】：

它对我很有用。但按钮不在屏幕底部。他们来到屏幕的顶部。我如何将它们保持在底部。
这里的txt1是什么？并且也没有识别出线性布局的底部

【解决方案3】：

试试这个

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
            LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
    layoutParams.gravity = Gravity.BOTTOM;
    rl.setLayoutParams(layoutParams);



    RelativeLayout.LayoutParams params1 = new RelativeLayout.LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

    params1.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);

    RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    params2.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE);

    RelativeLayout.LayoutParams params3 = new RelativeLayout.LayoutParams(
            (int) LayoutParams.WRAP_CONTENT,
            (int) LayoutParams.WRAP_CONTENT);

    params3.addRule(RelativeLayout.CENTER_HORIZONTAL);

    rl.addView(b1, params1);
    rl.addView(b2, params3);
    rl.addView(b3, params2);

    l.addView(rl);

【讨论】：

按钮不在屏幕底部。
我认为您在 activity_main.xml 文件中使用线性布局高度作为 wrap_content。对吗？
如果是，则将 layout_height 更改为 fill_parent。
让我们continue this discussion in chat
然后发布您的 activity_main.xml 文件

【解决方案4】：

试试这个： XML 文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="bottom"
    android:orientation="vertical"
    tools:context=".MainActivity" >

</LinearLayout>

在 JAVA 文件中：

 LinearLayout main = (LinearLayout) findViewById(R.id.main);

        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
                android.widget.RelativeLayout.LayoutParams.MATCH_PARENT,
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT);
        RelativeLayout ll = new RelativeLayout(getBaseContext());

        RelativeLayout.LayoutParams params1 = new RelativeLayout.LayoutParams(
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT,
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT);
        params1.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
        RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams(
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT,
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT);
        params2.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE);

        RelativeLayout.LayoutParams params3 = new RelativeLayout.LayoutParams(
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT,
                android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT);
        params3.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);

        Button btn1 = new Button(getBaseContext());
        Button btn2 = new Button(getBaseContext());
        Button btn3 = new Button(getBaseContext());

        btn1.setText("One");
        btn2.setText("Two");
        btn3.setText("Three");

        ll.addView(btn1, params1);
        ll.addView(btn2, params2);
        ll.addView(btn3, params3);

        main.addView(ll, params);

希望这会对你有所帮助。

【讨论】：

我希望通过 java 代码而不是通过 xml 创建相对布局
所以你的父 LINEAR LAYOUT 在 XML 文件中。对吗？？
我已经更新了我的答案。请检查更新。它对我有用。
它解决了我一半的问题。它工作得很好。但我还需要将这些按钮放在屏幕底部。你知道怎么做吗？

【解决方案5】：

我已经使用此代码以编程方式创建了布局：

public class MainActivity extends Activity {
    private LinearLayout layout; 
    private RelativeLayout lay;
    private Button btn1, btn2, btn3;

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

        layout = (LinearLayout)findViewById(R.id.ff);
        lay = new RelativeLayout(this);
        RelativeLayout.LayoutParams layout_params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        layout_params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        lay.setLayoutParams(layout_params);

        //lay.setLayoutParams(layout_params);
        btn1 = new Button(this);
        btn1.setText("ButtonA");
        btn2 = new Button(this);
        btn2.setText("ButtonB");
        btn3 = new Button(this);
        btn3.setText("ButtonC");

        RelativeLayout.LayoutParams button_params1 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        button_params1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        button_params1.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
        btn1.setLayoutParams(button_params1);

        RelativeLayout.LayoutParams button_params2 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        button_params2.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        button_params2.addRule(RelativeLayout.CENTER_HORIZONTAL);
        btn2.setLayoutParams(button_params2);

        RelativeLayout.LayoutParams button_params3 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        button_params3.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        button_params3.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
        btn3.setLayoutParams(button_params3);

        lay.addView(btn1);
        lay.addView(btn2);
        lay.addView(btn3);
        layout.addView(lay);



    }
}

【讨论】：

我不能有父级相对布局。父布局应该只是线性的。我需要将相对布局添加到父线性布局。