android - 如何以编程方式在 RelativeLayout 中布局视图？

Question

我正在尝试以编程方式（而不是通过 XML 以声明方式）实现以下目标：

<RelativeLayout...>
   <TextView ...
      android:id="@+id/label1" />
   <TextView ...
      android:id="@+id/label2"
      android:layout_below: "@id/label1" />
</RelativeLayout>

换句话说，我如何让第二个TextView出现在第一个下面，但我想在代码中做到这一点：

RelativeLayout layout = new RelativeLayout(this);
TextView label1 = new TextView(this);
TextView label2 = new TextView(this);
...
layout.addView(label1);
layout.addView(label2);
setContentView(layout);

更新：

谢谢，TreeUK。我理解大方向，但它仍然不起作用 - “B”与“A”重叠。我究竟做错了什么？

RelativeLayout layout = new RelativeLayout(this);
TextView tv1 = new TextView(this);
tv1.setText("A");

TextView tv2 = new TextView(this);
tv2.setText("B");
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
        RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.FILL_PARENT);
lp.addRule(RelativeLayout.RIGHT_OF, tv1.getId());

layout.addView(tv1);        
layout.addView(tv2, lp);

score 197 · Accepted Answer

从我能够拼凑的内容来看，您必须使用 LayoutParams 添加视图。

LinearLayout linearLayout = new LinearLayout(this);

RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(
        LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
relativeParams.addRule(RelativeLayout.ALIGN_PARENT_TOP);

parentView.addView(linearLayout, relativeParams);

所有功劳归功于 sechastain，以编程方式相对定位您的项目，您必须为它们分配 id。

TextView tv1 = new TextView(this);
tv1.setId(1);
TextView tv2 = new TextView(this);
tv2.setId(2);

然后addRule(RelativeLayout.RIGHT_OF, tv1.getId());

score 61 · Accepted Answer

长话短说：使用相对布局，您可以在布局内定位元素。

创建一个新的 RelativeLayout.LayoutParams
```
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(...)
```
（无论如何......填充父或包装内容，如果必须的话，绝对数字，或对 XML 资源的引用）

添加规则：规则引用父级或层次结构中的其他“兄弟”。

lp.addRule(RelativeLayout.BELOW, someOtherView.getId())
lp.addRule(RelativeLayout.ALIGN_PARENT_LEFT)

只需应用布局参数：最“健康”的方法是：
```
parentLayout.addView(myView, lp)
```

注意：不要从布局回调中更改布局。这样做很诱人，因为这是视图获得其实际大小的时候。但是，在这种情况下，会出现意想不到的结果。

score 29 · Accepted Answer

刚刚花了4个小时解决这个问题。终于意识到你不能使用零作为视图 id。你会认为它被允许为 NO_ID == -1，但如果你把它交给你的视图，事情往往会变得混乱......

score 9 · Accepted Answer

Android 22 最小可运行示例

资源：

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class Main extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        final RelativeLayout relativeLayout = new RelativeLayout(this);

        final TextView tv1;
        tv1 = new TextView(this);
        tv1.setText("tv1");
        // Setting an ID is mandatory.
        tv1.setId(View.generateViewId());
        relativeLayout.addView(tv1);

        // tv2.
        final TextView tv2;
        tv2 = new TextView(this);
        tv2.setText("tv2");
        RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.FILL_PARENT);
        lp.addRule(RelativeLayout.BELOW, tv1.getId());
        relativeLayout.addView(tv2, lp);

        // tv3.
        final TextView tv3;
        tv3 = new TextView(this);
        tv3.setText("tv3");
        RelativeLayout.LayoutParams lp2 = new RelativeLayout.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT,
            ViewGroup.LayoutParams.WRAP_CONTENT
        );
        lp2.addRule(RelativeLayout.BELOW, tv2.getId());
        relativeLayout.addView(tv3, lp2);

        this.setContentView(relativeLayout);
    }
}

与 .生成的默认项目一起使用android create project ...。具有最少构建代码的 GitHub 存储库。

score 7 · Accepted Answer

7

称呼

tv1.setId(1)

后

tv1.setText("A");

于 2010-03-23T12:15:00.720 回答

score 4 · Accepted Answer

尝试：

EditText edt = (EditText) findViewById(R.id.YourEditText);
RelativeLayout.LayoutParams lp =
    new RelativeLayout.LayoutParams
    (
        LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT
    );
lp.setMargins(25, 0, 0, 0); // move 25 px to right (increase left margin)
edt.setLayoutParams(lp); // lp.setMargins(left, top, right, bottom);

score 2 · Accepted Answer

ViewGroup.MarginLayoutParams 的这种方法对我有用：

RelativeLayout myLayout = (RelativeLayout) findViewById(R.id.my_layout);

TextView someTextView = ...

int leftMargin = Util.getXPos();
int topMargin = Util.getYPos();

RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
    new ViewGroup.MarginLayoutParams(
        RelativeLayout.LayoutParams.WRAP_CONTENT,
        RelativeLayout.LayoutParams.WRAP_CONTENT));

lp.setMargins(leftMargin, topMargin, 0, 0);

myLayout.addView(someTextView, lp);

score 1 · Accepted Answer

public class MainActivity extends AppCompatActivity {

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

        final RelativeLayout relativeLayout = new RelativeLayout(this);
        final TextView tv1 = new TextView(this);
        tv1.setText("tv1 is here");
        // Setting an ID is mandatory.
        tv1.setId(View.generateViewId());
        relativeLayout.addView(tv1);


        final TextView tv2 = new TextView(this);
        tv2.setText("tv2 is here");

        // We are defining layout params for tv2 which will be added to its  parent relativelayout.
        // The type of the LayoutParams depends on the parent type.
        RelativeLayout.LayoutParams tv2LayoutParams = new  RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.WRAP_CONTENT,
            RelativeLayout.LayoutParams.WRAP_CONTENT);

        //Also, we want tv2 to appear below tv1, so we are adding rule to tv2LayoutParams.
        tv2LayoutParams.addRule(RelativeLayout.BELOW, tv1.getId());

        //Now, adding the child view tv2 to relativelayout, and setting tv2LayoutParams to be set on view tv2.
        relativeLayout.addView(tv2);
        tv2.setLayoutParams(tv2LayoutParams);
        //Or we can combined the above two steps in one line of code
        //relativeLayout.addView(tv2, tv2LayoutParams);

        this.setContentView(relativeLayout);
    }

}

score 0 · Accepted Answer

如果您真的想手动布局，我建议您根本不要使用标准布局。全部由您自己完成，这里有一个 kotlin 示例：

class ProgrammaticalLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0) : ViewGroup(context, attrs, defStyleAttr) { 
    private val firstTextView = TextView(context).apply {
        test = "First Text"
    }

    private val secondTextView = TextView(context).apply {
        text = "Second Text"
    }

    init {
        addView(firstTextView)
        addView(secondTextView)
    }

    override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
        // center the views verticaly and horizontaly
        val firstTextLeft = (measuredWidth - firstTextView.measuredWidth) / 2
        val firstTextTop = (measuredHeight - (firstTextView.measuredHeight + secondTextView.measuredHeight)) / 2
        firstTextView.layout(firstTextLeft,firstTextTop, firstTextLeft + firstTextView.measuredWidth,firstTextTop + firstTextView.measuredHeight)

        val secondTextLeft = (measuredWidth - secondTextView.measuredWidth) / 2
        val secondTextTop = firstTextView.bottom
        secondTextView.layout(secondTextLeft,secondTextTop, secondTextLeft + secondTextView.measuredWidth,secondTextTop + secondTextView.measuredHeight)
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) { 
        // just assume we`re getting measured exactly by the parent
        val measuredWidth = MeasureSpec.getSize(widthMeasureSpec)
        val measuredHeight = MeasureSpec.getSize(heightMeasureSpec)

        firstTextView.measures(MeasureSpec.makeMeasureSpec(meeasuredWidth, MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED))
        secondTextView.measures(MeasureSpec.makeMeasureSpec(meeasuredWidth, MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED))

        setMeasuredDimension(measuredWidth, measuredHeight)
    }
}

这可能会让你知道它是如何工作的

android - 如何以编程方式在 RelativeLayout 中布局视图？

更新：

9 回答 9

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