(转载)Android 用纯代码实现复杂界面

在开发Android应用时有时会遇到纯代码实现复杂界面的需求，本文通过实例来演示，希望能对大家有所帮助

界面截图：

 XML布局文件：

<?xml version="1.0" encoding="utf-8"?>  
<ScrollView   
    xmlns:android="http://schemas.android.com/apk/res/android"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent"  
    android:background="@android:color/white">  
      
    <LinearLayout   
        android:layout_width="fill_parent"  
        android:layout_height="fill_parent"  
        android:orientation="vertical"  
        android:gravity="center">  
        <ImageView   
            android:layout_width="240dip"  
            android:layout_height="120dip"  
            android:layout_margin="30dip"  
            android:layout_gravity="center_horizontal"  
            android:background="@android:color/black"  
            android:scaleType="fitCenter"  
            android:adjustViewBounds="true"  
            android:src="@android:drawable/ic_dialog_map"/>  
        <TextView  
            android:layout_width="fill_parent"  
            android:layout_height="wrap_content"  
            android:layout_margin="30dip"  
            android:layout_gravity="center_horizontal"  
            android:gravity="center_horizontal"  
            android:textSize="18sp"  
            android:text="测试文本显示"/>  
        <EditText   
            android:layout_width="240dip"  
            android:layout_height="wrap_content"  
            android:layout_margin="30dip"  
            android:layout_gravity="center_horizontal"  
            android:hint="请输入文字内容"  
            android:maxLength="200"  
            android:textSize="18sp"/>  
        <LinearLayout   
            android:id="@+id/button_layout"  
            android:layout_width="240dip"  
            android:layout_height="wrap_content"  
            android:layout_gravity="center_horizontal"  
            android:background="#c6c3c6"  
            android:minHeight="54dip"  
            android:orientation="horizontal"  
            android:paddingTop="4dip"  
            android:paddingBottom="4dip"  
            android:paddingLeft="2dip"  
            android:paddingRight="2dip" >  
            <Button    
                android:text="确定 "  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_gravity="left"  
                android:layout_marginLeft="10dip"  
                android:layout_marginRight="5dip"  
                android:layout_weight="1"  
                android:maxLines="2"  
                android:textSize="18sp" />  
            <Button   
                android:text="取消"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_gravity="right"  
                android:layout_marginLeft="5dip"  
                android:layout_marginRight="10dip"  
                android:layout_weight="1"  
                android:maxLines="2"  
                android:textSize="18sp"/>  
        </LinearLayout>  
        <RelativeLayout   
            android:layout_width="fill_parent"  
            android:layout_height="wrap_content"  
            >  
            <ImageView   
                android:id="@+id/ImageBottom"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_below="@id/button_layout"  
                android:layout_centerHorizontal="true"  
                android:layout_margin="30dip"  
                android:background="#FF777777"  
                android:scaleType="fitCenter"  
                android:adjustViewBounds="true"  
                android:src="@android:drawable/ic_dialog_email"/>  
        </RelativeLayout>  
          
    </LinearLayout>  
      
</ScrollView> 

通过纯代码实现XML同样的效果：

import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.text.InputFilter;
import android.text.InputFilter.LengthFilter;
import android.view.Gravity;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import android.widget.TextView;

public class ActivityInfo extends Activity {
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
//        setContentView(R.layout.info);
        
        initUI();
    }
    
    public final void initUI(){
        ScrollView main = new ScrollView(this);
        main.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
        main.setBackgroundColor(Color.WHITE);
        
        //根布局参数
        LinearLayout.LayoutParams layoutParamsRoot = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.FILL_PARENT);
        layoutParamsRoot.gravity = Gravity.CENTER;
        //根布局
        LinearLayout layoutRoot = new LinearLayout(this);
        layoutRoot.setLayoutParams(layoutParamsRoot);
        layoutRoot.setOrientation(LinearLayout.VERTICAL);
        
        
        //上边距（dp值）
        int topMargin = dip2px(this, 30);
        //imageMain宽度（dp值）
        int widthMain = dip2px(this, 240);
        //imageMain高度（dp值）
        int heightMain = dip2px(this, 120);
        
        //imageMain布局参数
        LinearLayout.LayoutParams layoutParamsImageMain = new LinearLayout.LayoutParams(widthMain,heightMain);
        layoutParamsImageMain.topMargin = topMargin;
        layoutParamsImageMain.bottomMargin = topMargin;
        layoutParamsImageMain.leftMargin = topMargin;
        layoutParamsImageMain.rightMargin = topMargin;
        layoutParamsImageMain.gravity=Gravity.CENTER_HORIZONTAL;
        //初始化ImageView
        ImageView imageMain = new ImageView(this);
        imageMain.setScaleType(ScaleType.FIT_CENTER);
        imageMain.setAdjustViewBounds(true);
        imageMain.setBackgroundColor(Color.BLACK);
        imageMain.setImageResource(android.R.drawable.ic_dialog_map);
        layoutRoot.addView(imageMain, layoutParamsImageMain);
        
        //textInfo布局参数
        LinearLayout.LayoutParams layoutParamsTextInfo = new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);
        layoutParamsTextInfo.topMargin = topMargin;
        layoutParamsTextInfo.bottomMargin = topMargin;
        layoutParamsTextInfo.leftMargin = topMargin;
        layoutParamsTextInfo.rightMargin = topMargin;
        layoutParamsTextInfo.gravity=Gravity.CENTER_HORIZONTAL;
        //初始化textInfo
        TextView textInfo = new TextView(this);
        textInfo.setGravity(Gravity.CENTER_HORIZONTAL);
        textInfo.setTextSize(18);
        layoutRoot.addView(textInfo, layoutParamsTextInfo);
        
        //editInfo布局参数
        LinearLayout.LayoutParams layoutParamsEditInfo = new LinearLayout.LayoutParams(widthMain,LayoutParams.WRAP_CONTENT);
        layoutParamsEditInfo.topMargin = topMargin;
        layoutParamsEditInfo.gravity=Gravity.CENTER_HORIZONTAL;
        //初始化editInfo
        EditText editInfo = new EditText(this);
        editInfo.setHint("请输入文字内容");
        //设置可输入的最大长度
        InputFilter[] filters = {new LengthFilter(200)};  
        editInfo.setFilters(filters);
        editInfo.setTextSize(18);
        layoutRoot.addView(editInfo, layoutParamsEditInfo);
        
        //上边距（dp值）
        int minHeight = dip2px(this, 54);
        //上padding（dp值）
        int topPadding = dip2px(this, 4);
        //左padding（dp值）
        int leftPadding = dip2px(this, 2);
        //按钮布局
        LinearLayout layoutButton = new LinearLayout(this);
        layoutButton.setLayoutParams(layoutParamsEditInfo);
        layoutButton.setOrientation(LinearLayout.HORIZONTAL);
        layoutButton.setBackgroundColor(Color.parseColor("#c6c3c6"));
        layoutButton.setMinimumHeight(minHeight);
        layoutButton.setPadding(leftPadding, topPadding, leftPadding, topPadding);
        layoutButton.setId(100000001);
        
        //buttonOK布局参数
        LinearLayout.LayoutParams layoutParamsButtonOK = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        layoutParamsButtonOK.gravity = Gravity.LEFT;
        layoutParamsButtonOK.leftMargin = dip2px(this, 10);
        layoutParamsButtonOK.rightMargin = dip2px(this, 5);
        layoutParamsButtonOK.weight = 1;
        //Button确定
        Button buttonOK = new Button(this);
        buttonOK.setLayoutParams(layoutParamsButtonOK);
        buttonOK.setMaxLines(2);
        buttonOK.setTextSize(18);
        buttonOK.setText("确定");
        layoutButton.addView(buttonOK);
        
        //buttonCancel布局参数
        LinearLayout.LayoutParams layoutParamsButtonCancel = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        layoutParamsButtonCancel.gravity = Gravity.RIGHT;
        layoutParamsButtonCancel.leftMargin = dip2px(this, 5);
        layoutParamsButtonCancel.rightMargin = dip2px(this, 10);
        layoutParamsButtonCancel.weight = 1;
        //Button取消
        Button buttonCancel = new Button(this);
        buttonCancel.setLayoutParams(layoutParamsButtonCancel);
        buttonCancel.setMaxLines(2);
        buttonCancel.setTextSize(18);
        buttonCancel.setText("取消");
        
        layoutButton.addView(buttonCancel);
        
        layoutRoot.addView(layoutButton, layoutParamsEditInfo);
        
        //RelativeLayout布局参数
        LinearLayout.LayoutParams layoutParamsBottom = new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);
        RelativeLayout layoutBottom = new RelativeLayout(this);
        layoutBottom.setLayoutParams(layoutParamsBottom);
        
        RelativeLayout.LayoutParams paramsImageBottom = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        paramsImageBottom.addRule(RelativeLayout.BELOW, 100000001);
        paramsImageBottom.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
        paramsImageBottom.setMargins(topMargin, topMargin, topMargin, topMargin);
        
        //初始化ImageView
        ImageView imageBottom = new ImageView(this);
        imageBottom.setScaleType(ScaleType.FIT_CENTER);
        imageBottom.setAdjustViewBounds(true);
        imageBottom.setBackgroundColor(0xFF777777);
        imageBottom.setImageResource(android.R.drawable.ic_dialog_email);
        layoutBottom.addView(imageBottom, paramsImageBottom);
        layoutRoot.addView(layoutBottom);
        
        
        //TODO TEST
//        imageMain.setBackgroundResource(android.R.drawable.ic_dialog_map);
        textInfo.setText("测试文本显示");
        
        main.addView(layoutRoot);
        setContentView(main);
    }
    
    /**
     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
     */
    public static int dip2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    /**
     * 根据手机的分辨率从 px(像素) 的单位 转成为 dp
     */
    public static int px2dip(Context context, float pxValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

}

本文转载自：http://blog.csdn.net/gf771115/article/details/8237229