标签:tac enc import XML margin ati void tla vat
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <TextView
        android:id="@+id/tvTtitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.172"
        android:textSize="17dp"
        android:textColor="@color/myRed"
        />
    <Button
        android:id="@+id/btnSayHello"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="200dp"
        android:text="打招呼"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <Button
        android:id="@+id/btnRed"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="260dp"
        android:text="红色"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <Button
        android:id="@+id/btnGreen"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="320dp"
        android:text="绿色"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <Button
        android:id="@+id/btnBlue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="380dp"
        android:text="蓝色"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
------------------------------------------------------------------
ColorActivity.java
package com.example.dfby.myapplication;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class ColorActivity extends AppCompatActivity implements View.OnClickListener{
    private Button btnRed,btnGreen,btnBlue;
    private TextView tvTtitle;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.i("我的日志","这是我的自定义Activity");
        //设置有颜色
        tvTtitle=findViewById(R.id.tvTtitle);
        btnRed=findViewById(R.id.btnRed);//获取按钮对象
        btnGreen=findViewById(R.id.btnGreen);//获取按钮对象
        btnBlue=findViewById(R.id.btnBlue);//获取按钮对象
        btnRed.setOnClickListener(this);
        btnGreen.setOnClickListener(this);
        btnBlue.setOnClickListener(this);
}
    @Override
    public void onClick(View v) {
        Toast.makeText(this,"干嘛点击我",Toast.LENGTH_SHORT).show();
        if(v.getId()==R.id.btnRed){
            getWindow().setBackgroundDrawableResource(R.color.myRed);
        }else if(v.getId()==R.id.btnGreen){
            getWindow().setBackgroundDrawableResource(R.color.myGreen);
        }else if(v.getId()==R.id.btnBlue){
            getWindow().setBackgroundDrawableResource(R.color.myBlue);
        }
    }
}
标签:tac enc import XML margin ati void tla vat
原文地址:https://www.cnblogs.com/bj-tony/p/10243501.html