android 2C学习

**本次的App做的是一个篮球记分
1.首先还是布局，先观察一个队，两个TextView，三个Button，是线性垂直布局。可以用LinearLayout。
2.将一个队整个看成一个View,一共两个队加一个分割线，线性水平布局。所以在外层套一个LInerLayout。
3.将两个队和分割线看成一个View,和最后的Reset Button可以用RelativeLayout，所以最外层是RelativeLayout。
4.至于其他的字体颜色调整，以及Button响应之前都做过，比较容易。**

//xml代码<?xml version="1.0" encoding="utf-8"?><RelativeLayout   xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.ydh.courtcounter.MainActivity">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent">        <LinearLayout            android:layout_weight="1"            android:layout_width="0dp"            android:orientation="vertical"            android:layout_height="wrap_content">            <TextView                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:textSize="26sp"                android:gravity="center_horizontal"                android:text="Team A" />            <TextView                android:layout_width="match_parent"                android:id="@+id/Team_A"                android:textSize="60sp"                android:textColor="@android:color/black"                android:text="0"                android:gravity="center_horizontal"                android:layout_height="wrap_content" />            <Button                android:text="+3points"                android:layout_width="150dp"                android:background="@android:color/holo_blue_bright"                android:onClick="Team_A_3"                android:layout_gravity="center_horizontal"                android:layout_height="60dp" />            <Button                android:text="+2points"                android:layout_width="150dp"                android:layout_marginBottom="8dp"                android:background="@android:color/holo_blue_bright"                android:onClick="Team_A_2"                android:layout_marginTop="8dp"                android:layout_gravity="center_horizontal"                android:layout_height="60dp" />            <Button                android:text="+1point"                android:background="@android:color/holo_blue_bright"                android:onClick="Team_A_1"                android:layout_width="150dp"                android:layout_gravity="center_horizontal"                android:layout_height="60dp" />        </LinearLayout>        <View            android:layout_width="1dp"            android:background="@android:color/darker_gray"            android:layout_height="315dp" ></View>        <LinearLayout            android:layout_weight="1"            android:layout_width="0dp"            android:orientation="vertical"            android:layout_height="wrap_content">            <TextView                android:layout_width="match_parent"                android:textSize="26sp"                android:gravity="center_horizontal"                android:layout_height="wrap_content"                android:text="Team B" />            <TextView                android:layout_width="match_parent"                android:textSize="60sp"                android:id="@+id/Team_B"                android:textColor="@android:color/black"                android:text="0"                android:gravity="center_horizontal"                android:layout_height="wrap_content" />            <Button                android:text="+3points"                android:layout_width="150dp"                android:onClick="Team_B_3"                android:background="@android:color/holo_blue_bright"                android:layout_gravity="center_horizontal"                android:layout_height="60dp" />            <Button                android:text="+2points"                android:layout_gravity="center_horizontal"                android:layout_marginBottom="8dp"                android:onClick="Team_B_2"                android:layout_marginTop="8dp"                android:background="@android:color/holo_blue_bright"                android:layout_width="150dp"                android:layout_height="60dp" />            <Button                android:text="+1point"                android:layout_width="150dp"                android:onClick="Team_B_1"                android:background="@android:color/holo_blue_bright"                android:layout_gravity="center_horizontal"                android:layout_height="60dp" />        </LinearLayout>    </LinearLayout>    <Button        android:layout_width="150dp"        android:layout_alignParentBottom="true"        android:textSize="20dp"        android:layout_marginBottom="8dp"        android:onClick="Reset"        android:text="Reset"        android:background="@android:color/holo_purple"        android:layout_centerInParent="true"        android:layout_height="60dp" /></RelativeLayout>

//.java代码package com.example.ydh.courtcounter;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.TextView;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    int A_score=0,B_score=0;    public void Team_A_3(View v){        A_score=A_score+3;        displayA(A_score);    }    public void Team_A_2(View v){        A_score=A_score+2;        displayA(A_score);    }    public void Team_A_1(View v){        A_score=A_score+1;        displayA(A_score);    }    public void Team_B_3(View v){        B_score=B_score+3;        displayB(B_score);    }    public void Team_B_2(View v){        B_score=B_score+2;        displayB(B_score);    }    public void Team_B_1(View v){        B_score=B_score+1;        displayB(B_score);    }    public void Reset(View v){        A_score=0;        B_score=0;        displayA(A_score);        displayB(B_score);    }    public void displayA(int score){        TextView scoreView = (TextView) findViewById(R.id.Team_A);        scoreView.setText(String.valueOf(score));    }    public void displayB(int score){        TextView scoreView = (TextView) findViewById(R.id.Team_B);        scoreView.setText(String.valueOf(score));    }}