day16
自定义控件的学习,设计一个购物车内的数量的加减控制
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<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_horizontal" android:background="@drawable/selector_number_add_sub"> <Button android:id="@+id/btn_sub" android:layout_width="50dp" android:layout_height="wrap_content" android:background="@drawable/car_btn" android:textColor="@color/black" android:text="-"/> <TextView android:id="@+id/etxt_num" android:layout_width="70dp" android:layout_height="wrap_content" android:textColor="@color/black" android:minWidth="100dp" android:gravity="center"/> <Button android:id="@+id/btn_add" android:layout_width="50dp" android:layout_height="wrap_content" android:background="@drawable/car_btn" android:textColor="@color/black" android:text="+"/> </LinearLayout>
第一是布局是两个button实现加减功能,第二是中间设计一个Textview用来显示数字
代码实现功能,设计理念——对两个button设置监听事件,然后对textview的text设置数字
package Home.widget; import android.annotation.SuppressLint; import android.annotation.TargetApi; import android.content.Context; import android.graphics.drawable.Drawable; import android.os.Build; import androidx.appcompat.widget.TintTypedArray; import android.text.InputType; import android.util.AttributeSet; import android.view.LayoutInflater; import android.view.View; import android.widget.Button; import android.widget.LinearLayout; import android.widget.TextView; import com.example.expressdelivery.R; public class NumberAddSubView extends LinearLayout implements View.OnClickListener { public static final String TAG="NumberAddSubView"; public static final int DEFUALT_MAX=100; private TextView mEtxtNum; private Button mBtnAdd; private Button mBtnSub; private OnButtonClickListener onButtonClickListener; private LayoutInflater mInflater; private int value; private int minValue; private int maxValue=DEFUALT_MAX; public NumberAddSubView(Context context) { this(context, null); } public NumberAddSubView(Context context, AttributeSet attrs) { this(context, attrs, 0); } @SuppressLint("RestrictedApi") public NumberAddSubView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); mInflater = LayoutInflater.from(context); initView(); if(attrs!=null) { @SuppressLint("RestrictedApi") TintTypedArray a=TintTypedArray.obtainStyledAttributes(context,attrs,R.styleable.NumberAddSubView,defStyleAttr,0); @SuppressLint("RestrictedApi") int val = a.getInt(R.styleable.NumberAddSubView_value,0); setValue(val); @SuppressLint("RestrictedApi") int maxVal = a.getInt(R.styleable.NumberAddSubView_maxValue,0); if(maxVal!=0) setMaxValue(maxVal); @SuppressLint("RestrictedApi") int minVal = a.getInt(R.styleable.NumberAddSubView_minValue,0); setMinValue(minVal); @SuppressLint("RestrictedApi") Drawable etBackground = a.getDrawable(R.styleable.NumberAddSubView_editBackground); if(etBackground!=null) setEditTextBackground(etBackground); @SuppressLint("RestrictedApi") Drawable buttonAddBackground = a.getDrawable(R.styleable.NumberAddSubView_buttonAddBackgroud); if(buttonAddBackground!=null) setButtonAddBackgroud(buttonAddBackground); @SuppressLint("RestrictedApi") Drawable buttonSubBackground = a.getDrawable(R.styleable.NumberAddSubView_buttonSubBackgroud); if(buttonSubBackground!=null) setButtonSubBackgroud(buttonSubBackground); a.recycle(); } } private void initView(){ View view = mInflater.inflate(R.layout.widet_num_add_sub,this,true); mEtxtNum = (TextView) view.findViewById(R.id.etxt_num); mEtxtNum.setInputType(InputType.TYPE_NULL); mEtxtNum.setKeyListener(null); mBtnAdd = (Button) view.findViewById(R.id.btn_add); mBtnSub = (Button) view.findViewById(R.id.btn_sub); mBtnAdd.setOnClickListener(this); mBtnSub.setOnClickListener(this); } @Override public void onClick(View v) { if(v.getId() == R.id.btn_add){ numAdd(); if(onButtonClickListener !=null){ onButtonClickListener.onButtonAddClick(v,this.value); } } else if(v.getId()==R.id.btn_sub){ numSub(); if(onButtonClickListener !=null){ onButtonClickListener.onButtonSubClick(v,this.value); } } } private void numAdd(){ getValue(); if(this.value<=maxValue) this.value=+this.value+1; mEtxtNum.setText(value+""); } private void numSub(){ getValue(); if(this.value>minValue) this.value=this.value-1; mEtxtNum.setText(value+""); } public int getValue(){ String value = mEtxtNum.getText().toString(); if(value !=null && !"".equals(value)) this.value = Integer.parseInt(value); return this.value; } public void setValue(int value) { mEtxtNum.setText(value+""); this.value = value; } public void setMaxValue(int maxValue) { this.maxValue = maxValue; } public void setMinValue(int minValue) { this.minValue = minValue; } public void setEditTextBackground(Drawable drawable){ mEtxtNum.setBackgroundDrawable(drawable); } public void setEditTextBackground(int drawableId){ setEditTextBackground(getResources().getDrawable(drawableId)); } @TargetApi(Build.VERSION_CODES.JELLY_BEAN) public void setButtonAddBackgroud(Drawable backgroud){ this.mBtnAdd.setBackground(backgroud); } @TargetApi(Build.VERSION_CODES.JELLY_BEAN) public void setButtonSubBackgroud(Drawable backgroud){ this.mBtnSub.setBackground(backgroud); } public void setOnButtonClickListener(OnButtonClickListener onButtonClickListener) { this.onButtonClickListener = onButtonClickListener; } public interface OnButtonClickListener{ public void onButtonAddClick(View view, int value); public void onButtonSubClick(View view, int value); } }