【转】Android中 layoyt.xml转view对象

一、说明

添加视图文件的时候有两种方式:1、通过在xml文件定义layout；2、java代码编写

二、前言说明

1.构造xml文件

2.LayoutInflater

提到addview，首先要了解一下LayoutInflater类。这个类最主要的功能就是实现将xml表述的layout转化为View的功能。为了便于理解，我们可以将它与findViewById()作一比较，二者都是实例化某一对象，不同的是findViewById()是找xml布局文件下的具体widget控件实例化，而LayoutInflater找res/layout/下的xml布局文件来实例化的。

(1)创建

LayoutInflater inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);或

LayoutInflater inflater = LayoutInflater.from(Activity.this);或

LayoutInflater inflater = getLayoutInflater();

这三种方法本质是相同的。

(2)inflate()

用LayoutInflater.inflate() 将LayOut文件转化成VIew。

View view = inflater.inflate(R.layout.block_gym_album_list_item, null);

3.添加视图文件

三、步骤
1、通过在xml文件定义layout(block_gym_album_list_item.xml)

1 <!--?xml version="1.0" encoding="utf-8"?-->
2 <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:core="http://schemas.android.com/apk/res/com.gxtag.gym" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:padding="5dp">
3
4     <imageview android:id="@+id/iv_head_album" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/defaulthead">
5
6 </imageview></linearlayout>

block_gym_album_list_item.xml

2、main.xml

1 <!--?xml version="1.0" encoding="utf-8"?-->
2 <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/ll_parent" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical">
3
4     <include android:layout_width="fill_parent" android:layout_height="wrap_content" layout="@layout/block_head_back">
5
6 </include></linearlayout>

main.xml

3、

  1 package com.gxtag.gym.ui;
  2
  3 import android.app.Activity;
  4 import android.content.Context;
  5 import android.os.Bundle;
  6 import android.view.LayoutInflater;
  7 import android.view.View;
  8 import android.view.View.OnClickListener;
  9 import android.view.ViewGroup;
 10 import android.widget.LinearLayout;
 11 import android.widget.LinearLayout.LayoutParams;
 12 import android.widget.TextView;
 13
 14 import com.gxtag.gym.R;
 15 import com.icq.app.widget.StatedButton;
 16
 17 public class DynamicViewActivity extends Activity implements OnClickListener{
 18
 19     private Context mContext;
 20     private TextView mTv_title;
 21     private String title = "动态添加布局";
 22     private StatedButton mSbtn_back;
 23     private LinearLayout mLl_parent;
 24
 25     @Override
 26     protected void onCreate(Bundle savedInstanceState) {
 27         super.onCreate(savedInstanceState);
 28         setContentView(R.layout.activity_dynamic);
 29         mContext=this;
 30         initView();
 31         mLl_parent.addView(addView1());
 32         mLl_parent.addView(addView2());
 33
 34     }
 35
 36     private void initView() {
 37         // TODO 初始化视图
 38         mLl_parent=(LinearLayout) findViewById(R.id.ll_parent);
 39         mTv_title = (TextView) findViewById(R.id.tv_title);
 40         mTv_title.setText(String.format(String.format(
 41                 getResources().getString(R.string.title), title)));
 42         mSbtn_back = (StatedButton) findViewById(R.id.sbtn_navback);
 43         mSbtn_back.setOnClickListener(this);
 44
 45
 46     }
 47
 48     private View addView1() {
 49         // TODO 动态添加布局(xml方式)
 50         LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
 51                     LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
 52 //      LayoutInflater inflater1=(LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 53 //      LayoutInflater inflater2 = getLayoutInflater();
 54         LayoutInflater inflater3 = LayoutInflater.from(mContext);
 55         View view = inflater3.inflate(R.layout.block_gym_album_list_item, null);
 56         view.setLayoutParams(lp);
 57         return view;
 58
 59     }
 60
 61     private View addView2() {
 62         // TODO 动态添加布局(java方式)
 63         LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
 64                     LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
 65         LinearLayout view = new LinearLayout(this);
 66         view.setLayoutParams(lp);//设置布局参数
 67         view.setOrientation(LinearLayout.HORIZONTAL);// 设置子View的Linearlayout// 为垂直方向布局
 68         //定义子View中两个元素的布局
 69         ViewGroup.LayoutParams vlp = new ViewGroup.LayoutParams(
 70                 ViewGroup.LayoutParams.WRAP_CONTENT,
 71                 ViewGroup.LayoutParams.WRAP_CONTENT);
 72         ViewGroup.LayoutParams vlp2 = new ViewGroup.LayoutParams(
 73                 ViewGroup.LayoutParams.WRAP_CONTENT,
 74                 ViewGroup.LayoutParams.WRAP_CONTENT);
 75
 76         TextView tv1 = new TextView(this);
 77         TextView tv2 = new TextView(this);
 78         tv1.setLayoutParams(vlp);//设置TextView的布局
 79         tv2.setLayoutParams(vlp2);
 80         tv1.setText("姓名:");
 81         tv2.setText("李四");
 82         tv2.setPadding(calculateDpToPx(50), 0, 0, 0);//设置边距
 83         view.addView(tv1);//将TextView 添加到子View 中
 84         view.addView(tv2);//将TextView 添加到子View 中
 85         return view;
 86     }
 87
 88     private int calculateDpToPx(int padding_in_dp){
 89         final float scale = getResources().getDisplayMetrics().density;
 90         return  (int) (padding_in_dp * scale + 0.5f);
 91     }
 92
 93
 94     @Override
 95     public void onClick(View v) {
 96         // TODO 控件单击事件
 97         switch (v.getId()) {
 98         case R.id.sbtn_navback:
 99             this.finish();
100             break;
101         default:
102             break;
103         }
104     }
105
106 }

Java