Android 开发笔记___RelativeLayout

Posted 2020-09-26 alm

 

xml文件实现

 

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     android:layout_width="match_parent"
 3     android:layout_height="500dp" >
 4 
 5     <Button
 6         android:id="@+id/btn_center"
 7         style="@style/btn_relative"
 8         android:layout_centerInParent="true"
 9         android:text="我在中间" />
10 
11     <Button
12         android:id="@+id/btn_center_horizontal"
13         style="@style/btn_relative"
14         android:layout_centerHorizontal="true"
15         android:text="我在水平中间" />
16 
17     <Button
18         android:id="@+id/btn_center_vertical"
19         style="@style/btn_relative"
20         android:layout_centerVertical="true"
21         android:text="我在垂直中间" />
22 
23     <Button
24         android:id="@+id/btn_parent_left"
25         style="@style/btn_relative"
26         android:layout_marginTop="100dp"
27         android:layout_alignParentLeft="true"
28         android:text="我跟上级左边对齐" />
29 
30     <Button
31         android:id="@+id/btn_parent_top"
32         style="@style/btn_relative"
33         android:layout_width="120dp"
34         android:layout_alignParentTop="true"
35         android:text="我跟上级顶部对齐" />
36 
37     <Button
38         android:id="@+id/btn_parent_right"
39         style="@style/btn_relative"
40         android:layout_marginTop="100dp"
41         android:layout_alignParentRight="true"
42         android:text="我跟上级右边对齐" />
43 
44     <Button
45         android:id="@+id/btn_parent_bottom"
46         style="@style/btn_relative"
47         android:layout_width="120dp"
48         android:layout_alignParentBottom="true"
49         android:layout_centerHorizontal="true"
50         android:text="我跟上级底部对齐" />
51 
52     <Button
53         android:id="@+id/btn_left_bottom"
54         style="@style/btn_relative"
55         android:layout_toLeftOf="@+id/btn_parent_bottom"
56         android:layout_alignTop="@+id/btn_parent_bottom"
57         android:text="我在底部左边" />
58 
59     <Button
60         android:id="@+id/btn_right_bottom"
61         style="@style/btn_relative"
62         android:layout_toRightOf="@+id/btn_parent_bottom"
63         android:layout_alignBottom="@+id/btn_parent_bottom"
64         android:text="我在底部右边" />
65 
66     <Button
67         android:id="@+id/btn_above_center"
68         style="@style/btn_relative"
69         android:layout_above="@+id/btn_center"
70         android:layout_alignLeft="@+id/btn_center"
71         android:text="我在中间上面" />
72 
73     <Button
74         android:id="@+id/btn_below_center"
75         style="@style/btn_relative"
76         android:layout_below="@+id/btn_center"
77         android:layout_alignRight="@+id/btn_center"
78         android:text="我在中间下面" />
79 
80 </RelativeLayout>

java

 1 package com.example.alimjan.hello_world;
 2 
 3 import android.content.Context;
 4 import android.content.Intent;
 5 import android.os.Bundle;
 6 import android.support.annotation.Nullable;
 7 import android.support.v7.app.AppCompatActivity;
 8 
 9 import com.example.alimjan.hello_world.two.class__2_1;
10 
11 /**
12  * Created by alimjan on 7/2/2017.
13  */
14 
15 public class class_3_1_1 extends AppCompatActivity{
16     @Override
17     protected void onCreate(@Nullable Bundle savedInstanceState) {
18         super.onCreate(savedInstanceState);
19         setContentView(R.layout.code_3_1_1);
20     }
21 
22     public static void startHome(Context mContext) {
23         Intent intent = new Intent(mContext, class_3_1_1.class);
24         mContext.startActivity(intent);
25     }
26 }

 

代码实现

 

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     android:id="@+id/rl_content"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent" >
 5 
 6     <TextView
 7         style="@style/btn_relative"
 8         android:layout_alignParentTop="true"
 9         android:layout_centerHorizontal="true"
10         android:text="点击按钮添加视图，长按视图删除自身" />
11 
12     <Button
13         android:id="@+id/btn_add_left"
14         style="@style/btn_relative"
15         android:layout_marginTop="80dp"
16         android:layout_centerHorizontal="true"
17         android:text="添加左边视图" />
18 
19     <Button
20         android:id="@+id/btn_add_above"
21         style="@style/btn_relative"
22         android:layout_below="@+id/btn_add_left"
23         android:layout_alignLeft="@+id/btn_add_left"
24         android:text="添加上方视图" />
25 
26     <Button
27         android:id="@+id/btn_add_right"
28         style="@style/btn_relative"
29         android:layout_below="@+id/btn_add_above"
30         android:layout_alignLeft="@+id/btn_add_left"
31         android:text="添加右边视图" />
32 
33     <Button
34         android:id="@+id/btn_add_below"
35         style="@style/btn_relative"
36         android:layout_below="@+id/btn_add_right"
37         android:layout_alignLeft="@+id/btn_add_left"
38         android:text="添加下方视图" />
39 
40     <Button
41         android:id="@+id/btn_add_center"
42         style="@style/btn_relative"
43         android:layout_below="@+id/btn_add_below"
44         android:layout_alignLeft="@+id/btn_add_left"
45         android:text="添加中间视图" />
46 
47     <Button
48         android:id="@+id/btn_add_parent_left"
49         style="@style/btn_relative"
50         android:layout_below="@+id/btn_add_center"
51         android:layout_alignLeft="@+id/btn_add_left"
52         android:text="添加上级左侧对齐视图" />
53 
54     <Button
55         android:id="@+id/btn_add_parent_top"
56         style="@style/btn_relative"
57         android:layout_below="@+id/btn_add_parent_left"
58         android:layout_alignLeft="@+id/btn_add_left"
59         android:text="添加上级顶部对齐视图" />
60 
61     <Button
62         android:id="@+id/btn_add_parent_right"
63         style="@style/btn_relative"
64         android:layout_below="@+id/btn_add_parent_top"
65         android:layout_alignLeft="@+id/btn_add_left"
66         android:text="添加上级右侧对齐视图" />
67 
68     <Button
69         android:id="@+id/btn_add_parent_bottom"
70         style="@style/btn_relative"
71         android:layout_below="@+id/btn_add_parent_right"
72         android:layout_alignLeft="@+id/btn_add_left"
73         android:text="添加上级底部对齐视图" />
74 
75 </RelativeLayout>

 1 package com.example.alimjan.hello_world;
 2 
 3 import android.content.Context;
 4 import android.content.Intent;
 5 import android.os.Bundle;
 6 import android.support.v7.app.AppCompatActivity;
 7 import android.view.View;
 8 import android.widget.RelativeLayout;
 9 
10 /**
11  * Created by alimjan on 7/2/2017.
12  */
13 
14 
15 public class class_3_1_1_code extends AppCompatActivity implements View.OnClickListener {
16 
17     private RelativeLayout rl_content;
18 
19     @Override
20     protected void onCreate(Bundle savedInstanceState) {
21         super.onCreate(savedInstanceState);
22         setContentView(R.layout.code_3_1_1_code);
23 
24         rl_content = (RelativeLayout) findViewById(R.id.rl_content);
25         findViewById(R.id.btn_add_left).setOnClickListener(this);
26         findViewById(R.id.btn_add_above).setOnClickListener(this);
27         findViewById(R.id.btn_add_right).setOnClickListener(this);
28         findViewById(R.id.btn_add_below).setOnClickListener(this);
29         findViewById(R.id.btn_add_center).setOnClickListener(this);
30         findViewById(R.id.btn_add_parent_left).setOnClickListener(this);
31         findViewById(R.id.btn_add_parent_top).setOnClickListener(this);
32         findViewById(R.id.btn_add_parent_right).setOnClickListener(this);
33         findViewById(R.id.btn_add_parent_bottom).setOnClickListener(this);
34     }
35 
36     @Override
37     public void onClick(View v) {
38         if (v.getId() == R.id.btn_add_left) {
39             addNewView(RelativeLayout.LEFT_OF, RelativeLayout.ALIGN_TOP, v.getId());
40         } else if (v.getId() == R.id.btn_add_above) {
41             addNewView(RelativeLayout.ABOVE, RelativeLayout.ALIGN_LEFT, v.getId());
42         } else if (v.getId() == R.id.btn_add_right) {
43             addNewView(RelativeLayout.RIGHT_OF, RelativeLayout.ALIGN_BOTTOM, v.getId());
44         } else if (v.getId() == R.id.btn_add_below) {
45             addNewView(RelativeLayout.BELOW, RelativeLayout.ALIGN_RIGHT, v.getId());
46         } else if (v.getId() == R.id.btn_add_center) {
47             addNewView(RelativeLayout.CENTER_IN_PARENT, -1, rl_content.getId());
48         } else if (v.getId() == R.id.btn_add_parent_left) {
49             addNewView(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.CENTER_VERTICAL, rl_content.getId());
50         } else if (v.getId() == R.id.btn_add_parent_top) {
51             addNewView(RelativeLayout.ALIGN_PARENT_TOP, RelativeLayout.CENTER_HORIZONTAL, rl_content.getId());
52         } else if (v.getId() == R.id.btn_add_parent_right) {
53             addNewView(RelativeLayout.ALIGN_PARENT_RIGHT, -1, rl_content.getId());
54         } else if (v.getId() == R.id.btn_add_parent_bottom) {
55             addNewView(RelativeLayout.ALIGN_PARENT_BOTTOM, -1, rl_content.getId());
56         }
57     }
58 
59     private void addNewView(int firstAlign, int secondAlign, int referId) {
60         View v = new View(this);
61         v.setBackgroundColor(0xaa66ff66);
62         RelativeLayout.LayoutParams rl_params = new RelativeLayout.LayoutParams(100, 100);
63         rl_params.addRule(firstAlign, referId);
64         if (secondAlign >= 0) {
65             rl_params.addRule(secondAlign, referId);
66         }
67         v.setLayoutParams(rl_params);
68         v.setOnLongClickListener(new View.OnLongClickListener() {
69             @Override
70             public boolean onLongClick(View vv) {
71                 rl_content.removeView(vv);
72                 return true;
73             }
74         });
75         rl_content.addView(v);
76     }
77 
78     public static void startHome(Context mContext) {
79         Intent intent = new Intent(mContext, class_3_1_1_code.class);
80         mContext.startActivity(intent);
81     }
82 
83 }