Android初学习 - 在布局中动态添加view的两种方法

       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)

<!--?xml version="1.0" encoding="utf-8"?--><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">     <imageview android:id="@+id/iv_head_album" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/defaulthead"> </imageview></linearlayout>

2、main.xml

<!--?xml version="1.0" encoding="utf-8"?--><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">     <include android:layout_width="fill_parent" android:layout_height="wrap_content" layout="@layout/block_head_back"></include></linearlayout>

3、DynamicViewActivity.xml

 import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.LinearLayout;import android.widget.LinearLayout.LayoutParams;import android.widget.TextView; import com.gxtag.gym.R;import com.icq.app.widget.StatedButton; public class DynamicViewActivity extends Activity implements OnClickListener{     private Context mContext;    private TextView mTv_title;    private String title = "动态添加布局";    private StatedButton mSbtn_back;    private LinearLayout mLl_parent;     @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_dynamic);        mContext=this;        initView();        mLl_parent.addView(addView1());        mLl_parent.addView(addView2());     }         private void initView() {        // TODO 初始化视图        mLl_parent=(LinearLayout) findViewById(R.id.ll_parent);        mTv_title = (TextView) findViewById(R.id.tv_title);        mTv_title.setText(String.format(String.format(                getResources().getString(R.string.title), title)));        mSbtn_back = (StatedButton) findViewById(R.id.sbtn_navback);        mSbtn_back.setOnClickListener(this);                      }         private View addView1() {        // TODO 动态添加布局(xml方式)        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(                     LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT); //      LayoutInflater inflater1=(LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);//      LayoutInflater inflater2 = getLayoutInflater();        LayoutInflater inflater3 = LayoutInflater.from(mContext);        View view = inflater3.inflate(R.layout.block_gym_album_list_item, null);        view.setLayoutParams(lp);        return view;             }         private View addView2() {        // TODO 动态添加布局(java方式)        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(                     LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);         LinearLayout view = new LinearLayout(this);         view.setLayoutParams(lp);//设置布局参数         view.setOrientation(LinearLayout.HORIZONTAL);// 设置子View的Linearlayout// 为垂直方向布局         //定义子View中两个元素的布局         ViewGroup.LayoutParams vlp = new ViewGroup.LayoutParams(                 ViewGroup.LayoutParams.WRAP_CONTENT,                 ViewGroup.LayoutParams.WRAP_CONTENT);         ViewGroup.LayoutParams vlp2 = new ViewGroup.LayoutParams(                 ViewGroup.LayoutParams.WRAP_CONTENT,                 ViewGroup.LayoutParams.WRAP_CONTENT);                   TextView tv1 = new TextView(this);         TextView tv2 = new TextView(this);         tv1.setLayoutParams(vlp);//设置TextView的布局         tv2.setLayoutParams(vlp2);         tv1.setText("姓名:");         tv2.setText("李四");         tv2.setPadding(calculateDpToPx(50), 0, 0, 0);//设置边距         view.addView(tv1);//将TextView 添加到子View 中         view.addView(tv2);//将TextView 添加到子View 中         return view;     }     private int calculateDpToPx(int padding_in_dp){         final float scale = getResources().getDisplayMetrics().density;         return  (int) (padding_in_dp * scale + 0.5f);     }           @Override    public void onClick(View v) {        // TODO 控件单击事件        switch (v.getId()) {        case R.id.sbtn_navback:            this.finish();            break;        default:            break;        }    } }