自定义仿京东加减图标

首先 attrs-xml

<declare-styleable name="AmountView">

<attr name="btnWidth" format="dimension" />

<attr name="tvWidth" format="dimension" />

<attr name="tvTextSize" format="dimension"/>
<attr name="btnTextSize" format="dimension"/>
<attr name="num" format="integer">attr>
declare-styleable>

//继承LinearLayout实现自定义

package com.bawei.myapplication.Houxiang;
import android.content.Context;
import android.content.res.TypedArray;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import com.bawei.myapplication.R;
/**
 * 自定义组件：购买数量，带减少增加按钮
 * Created by hiwhitley on 2016/7/4.
 */
public class AmountView extends LinearLayout implements View.OnClickListener, TextWatcher {

    private static final String TAG = "AmountView";

    private int amount =1; //购买数量
    private int goods_storage = 1; //商品库存

    private OnAmountChangeListener mListener;

    private EditText etAmount;
    private Button btnDecrease;
    private Button btnIncrease;

    public AmountView(Context context) {
        this(context, null);
    }

    public AmountView(Context context, AttributeSet attrs) {
        super(context, attrs);

        LayoutInflater.from(context).inflate(R.layout.view_amount, this);
        etAmount = (EditText) findViewById(R.id.tv_sum);
        btnDecrease = (Button) findViewById(R.id.btnDecrease);
        btnIncrease = (Button) findViewById(R.id.btnIncrease);
        btnDecrease.setOnClickListener(this);
        btnIncrease.setOnClickListener(this);
        etAmount.addTextChangedListener(this);

        TypedArray obtainStyledAttributes = getContext().obtainStyledAttributes(attrs, R.styleable.AmountView);
        int btnWidth = obtainStyledAttributes.getDimensionPixelSize(R.styleable.AmountView_btnWidth, 30);
        int tvWidth = obtainStyledAttributes.getDimensionPixelSize(R.styleable.AmountView_tvWidth, 30);
        int tvTextSize = obtainStyledAttributes.getDimensionPixelSize(R.styleable.AmountView_tvTextSize, 0);
        int btnTextSize = obtainStyledAttributes.getDimensionPixelSize(R.styleable.AmountView_btnTextSize, 0);

        obtainStyledAttributes.recycle();

        LayoutParams btnParams = new LayoutParams(btnWidth, LayoutParams.MATCH_PARENT);
        btnDecrease.setLayoutParams(btnParams);
        btnIncrease.setLayoutParams(btnParams);
        if (btnTextSize != 0) {
            btnDecrease.setTextSize(TypedValue.COMPLEX_UNIT_PX, btnTextSize);
            btnIncrease.setTextSize(TypedValue.COMPLEX_UNIT_PX, btnTextSize);
        }

        LayoutParams textParams = new LayoutParams(tvWidth, LayoutParams.MATCH_PARENT);
        etAmount.setLayoutParams(textParams);
        if (tvTextSize != 0) {
            etAmount.setTextSize(tvTextSize);
        }

    }






    public void setOnAmountChangeListener(OnAmountChangeListener onAmountChangeListener) {
        this.mListener = onAmountChangeListener;
    }

    public void setGoods_storage(int goods_storage) {
        this.goods_storage = goods_storage;
    }

    @Override
    public void onClick(View v) {
        int i = v.getId();
        if (i == R.id.btnDecrease) {
            if (amount > 1) {
                amount--;
                etAmount.setText(amount + "");
            }
        } else if (i == R.id.btnIncrease) {
            if (amount < goods_storage) {
                amount++;
                etAmount.setText(amount + "");
            }
        }

        etAmount.clearFocus();

        if (mListener != null) {
            mListener.onAmountChange(this, amount);
        }
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {

    }

    @Override
    public void afterTextChanged(Editable s) {
        if (s.toString().isEmpty())
            return;
        amount = Integer.valueOf(s.toString());
        if (amount > goods_storage) {
            etAmount.setText(goods_storage + "");
            return;
        }

        if (mListener != null) {
            mListener.onAmountChange(this, amount);
        }
    }


    public interface OnAmountChangeListener {
        void onAmountChange(View view, int amount);
    }
    public void setamount(int num){
        this.amount=num;
        etAmount.setText(amount+"");
        postInvalidate();
    }

}

1.下面我们来看自定义的布局

xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:focusable="true"
    android:background="@drawable/bg_amount_layout"
    android:showDividers="middle"
    android:orientation="horizontal">
     <Button
        android:id="@+id/btnDecrease"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:background="@drawable/btn_amount"
        android:text="-"/>

     <EditText
        android:id="@+id/tv_sum"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:minWidth="100dp"
        android:layout_weight="2"
        android:background="@null"
        android:inputType="number"
        android:gravity="center"
        android:text="1"/>
     <Button
        android:id="@+id/btnIncrease"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:background="@drawable/btn_amount"
        android:text="+"/>
LinearLayout>

//bg_amount_layout.xml

xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="#FFFFFF" />
<stroke
    android:width="1dp"
    android:color="@color/divider" />
<padding
    android:bottom="1dp"
    android:left="1dp"
    android:right="1dp"
    android:top="1dp" />
shape>

//btn_amount.xml

xml version="1.0" encoding="utf-8"?>
<selector
  xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@color/divider" />
    <item android:state_enabled="false" android:drawable="@color/divider" />
    <item android:drawable="@android:color/white" />
selector>

//MainActivity

AmountView mo= (AmountView) findViewById(R.id.num);

//设置最大值
mo.setGoods_storage(5);

//设置最小值
mo.setamount(1);