Android UI開發詳解之模板控件的復用

Android的UI設計一直是Android程序員比較苦惱的一件事，本文主要講解如何將一些模板類控件進行復用，從而簡化UI的開發。

如圖：

我們很多程序的界面中，頂部的TopBar是不變的，所以，我們可以做一個公用的控件模板，每次使用時，只要設置相應的參數，就能生成這樣一個TopBar。

模板控件實現方法：

package com.xys.multiplexedmodule;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.text.TextUtils.TruncateAt;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MultipleTopBar extends RelativeLayout{

private Button btn_left;
private Button btn_right;
private TextView tv_title;

private TopBarClickListener topBarClickListener;
private String str_title;

private RelativeLayout.LayoutParams leftButtonLayoutParams;
private RelativeLayout.LayoutParams rightButtonLayoutParams;
private RelativeLayout.LayoutParams tvTitleLayoutParams;

private static int leftBtnId=1;
private static int titleTvId=2;
private static int rightBtnId=3;

private Drawable leftBtnBackground;
private Drawable rightBtnBackground;

private String str_LeftBtn;
private String str_RightBtn;
private int leftBtnColor;
private int rightBtnColor;
private int titleTvColor;

private float titleTextSize;

public MultipleTopBar(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
//從參數列表中獲取參數
//TypedArray實例是個屬性的容器，context.obtainStyledAttributes()方法返回得到。AttributeSet是節點的屬性集合
//第二個參數為 為獲取到值時的默認值
TypedArray ta=context.obtainStyledAttributes(attrs,R.styleable.TopBar);
this.str_title=ta.getString(R.styleable.TopBar_title);
this.leftBtnBackground=ta.getDrawable(R.styleable.TopBar_leftBackground);
this.rightBtnBackground=ta.getDrawable(R.styleable.TopBar_rightBackground);
this.str_LeftBtn=ta.getString(R.styleable.TopBar_leftText);
this.str_RightBtn=ta.getString(R.styleable.TopBar_rightText);
this.leftBtnColor=ta.getColor(R.styleable.TopBar_leftTextColor, 0);
this.rightBtnColor=ta.getColor(R.styleable.TopBar_rightTextColor, 0);
this.titleTextSize=ta.getDimension(R.styleable.TopBar_titleTextSize, 14);
this.titleTvColor=ta.getColor(R.styleable.TopBar_titleTextColor, 0);

ta.recycle();

btn_left=new Button(context);
btn_right=new Button(context);
tv_title=new TextView(context);

btn_left.setId(leftBtnId);
btn_right.setId(rightBtnId);
tv_title.setId(titleTvId);

//為組件配置布局參數
leftButtonLayoutParams=new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
rightButtonLayoutParams=new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
tvTitleLayoutParams=new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);

leftButtonLayoutParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT,RelativeLayout.TRUE);
leftButtonLayoutParams.setMargins(12, 0, 0, 0);//左上右下
leftButtonLayoutParams.addRule(RelativeLayout.CENTER_VERTICAL, RelativeLayout.TRUE);

rightButtonLayoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT,RelativeLayout.TRUE);
rightButtonLayoutParams.setMargins(0, 0, 12, 0);//左上右下
rightButtonLayoutParams.addRule(RelativeLayout.CENTER_VERTICAL, RelativeLayout.TRUE);

tvTitleLayoutParams.setMargins(12, 0, 12, 0);//左上右下
tvTitleLayoutParams.addRule(RelativeLayout.CENTER_VERTICAL, RelativeLayout.TRUE);
tvTitleLayoutParams.addRule(RelativeLayout.LEFT_OF, rightBtnId);
tvTitleLayoutParams.addRule(RelativeLayout.RIGHT_OF, leftBtnId);
//tvTitleLayoutParams.addRule(RelativeLayout.CENTER_IN_PARENT, RelativeLayout.TRUE);
tv_title.setGravity(Gravity.CENTER);
tv_title.setBackgroundColor(leftBtnColor);

addView(btn_left, leftButtonLayoutParams);
addView(btn_right,rightButtonLayoutParams);
addView(tv_title,tvTitleLayoutParams);

//btn_left.setBackgroundDrawable(leftBtnBackground);
btn_left.setText(str_LeftBtn);
btn_left.setTextColor(leftBtnColor);
//btn_right.setBackgroundDrawable(rightBtnBackground);
btn_right.setText(str_RightBtn);
btn_right.setTextColor(rightBtnColor);

tv_title.setTextSize(22.0f);
tv_title.setTextColor(Color.BLUE);
tv_title.setEllipsize(TruncateAt.MIDDLE);
tv_title.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.CENTER_VERTICAL);
tv_title.setSingleLine(true);
tv_title.setText(str_title);
tv_title.setTextSize(titleTextSize);
tv_title.setTextColor(titleTvColor);

btn_left.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(topBarClickListener!=null){
topBarClickListener.leftBtnClick();
}
}
});

btn_right.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(topBarClickListener!=null){
topBarClickListener.rightBtnClick();
}
}
});

}

/*
* 單擊監聽事件
*/
public void setTopBarClickListener(TopBarClickListener topBarClickListener){
this.topBarClickListener=topBarClickListener;
}
}