一.画笔
import android.app.Fragment;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Shader;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.RelativeLayout;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FrameLayout fragment = (FrameLayout) findViewById(R.id.frameLayout); //获取帧布局管理器
fragment.addView(new MyView(this)); //将自定义视图的内部类添加到布局管理器中
}
private class MyView extends View {
public MyView(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) { //重写onDraw()方法
Paint paint = new Paint(); //定义一个默认的画笔
//线性渐变
Shader shader = new LinearGradient(0, 0, 100, 100,
Color.RED, Color.GREEN, Shader.TileMode.MIRROR);
paint.setShader(shader); //为画笔设置渐变器
canvas.drawRect(10, 10, 280, 150, paint); //绘制矩形
super.onDraw(canvas);
}
}
}
二.绘制几何体
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.RelativeLayout;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FrameLayout frameLayout= (FrameLayout) findViewById(R.id.frameLayout); //获取帧布局管理器
frameLayout.addView(new MyView(this)); //将自定义视图的内部类添加到布局管理器中
}
private class MyView extends View {
public MyView(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint=new Paint(); //默认设置创建一个画笔
paint.setAntiAlias(true); //使用抗锯齿功能
paint.setColor(0xFFA4C739); //设置画笔的颜色为绿色
//绘制机器人的头
RectF rectf_head=new RectF(10, 10, 100, 100);
rectf_head.offset(90, 20);
canvas.drawArc(rectf_head, -10, -160, false, paint); //绘制弧
//绘制眼睛
paint.setColor(Color.WHITE); //设置画笔的颜色为白色
canvas.drawCircle(125, 53, 4, paint); //绘制圆
canvas.drawCircle(165, 53, 4, paint); //绘制圆
paint.setColor(0xFFA4C739); //设置画笔的颜色为绿色
//绘制天线
paint.setStrokeWidth(2); //设置笔触的宽度
canvas.drawLine(110, 15, 125, 35, paint); //绘制线
canvas.drawLine(180, 15, 165, 35, paint); //绘制线
//绘制身体
canvas.drawRect(100, 75, 190, 150, paint); //绘制矩形
RectF rectf_body=new RectF(100,140,190,160);
canvas.drawRoundRect(rectf_body, 10, 10, paint); //绘制圆角矩形
//绘制胳膊
RectF rectf_arm=new RectF(75,75,95,140);
canvas.drawRoundRect(rectf_arm, 10, 10, paint); //绘制左侧的胳膊
rectf_arm.offset(120, 0); //设置在X轴上偏移120像素
canvas.drawRoundRect(rectf_arm, 10, 10, paint); //绘制右侧的胳膊
//绘制腿
RectF rectf_leg=new RectF(115,150,135,200);
canvas.drawRoundRect(rectf_leg, 10, 10, paint); //绘制左侧的腿
rectf_leg.offset(40, 0); //设置在X轴上偏移40像素
canvas.drawRoundRect(rectf_leg, 10, 10, paint); //绘制右侧的腿
}
}
}
三.绘制图像
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//获取布局文件中添加的帧布局管理器
FrameLayout frameLayout = (FrameLayout) findViewById(R.id.frameLayout);
frameLayout.addView(new MyView(this)); //将自定义的MyView视图添加到帧布局管理器中
}
private class MyView extends View {
public MyView(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
Paint paint = new Paint(); //创建一个采用默认设置的画笔
String path = Environment.getExternalStorageDirectory() + "/HeadImage.jpg"; //指定图片文件的路径
Bitmap bm = BitmapFactory.decodeFile(path); //获取图片文件对应的Bitmap对象
canvas.drawBitmap(bm, 0, 30, paint); //将获取的Bitmap对象绘制在画布的指定位置
Rect src = new Rect(105, 70, 220, 170); //设置挖取的区域
Rect dst = new Rect(350, 90, 465, 190); //设置绘制的区域
canvas.drawBitmap(bm, src, dst, paint); //绘制挖取到的图像
}
}
}
别忘了在使用SD卡资源时需要获取的权限
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
四.逐帧动画
import android.graphics.drawable.AnimationDrawable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity {
private boolean flag = true;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout linearLayout= (LinearLayout) findViewById(R.id.linearLayout); //获取布局管理器
//获取AnimationDrawable对象
final AnimationDrawable anim= (AnimationDrawable) linearLayout.getBackground();
linearLayout.setOnClickListener(new View.OnClickListener() { //为布局管理器添加单击事件
@Override
public void onClick(View v) {
if(flag){
anim.start(); //开始播放动画
flag=false;
}else {
anim.stop(); //停止播放动画
flag=true;
}
}
});
}
}
在drawable文件夹中编写动画代码.xml
<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/img001" android:duration="60"/>
<item android:drawable="@drawable/img002" android:duration="60"/>
<item android:drawable="@drawable/img003" android:duration="60"/>
<item android:drawable="@drawable/img004" android:duration="60"/>
<item android:drawable="@drawable/img005" android:duration="60"/>
<item android:drawable="@drawable/img006" android:duration="60"/>
</animation-list>
五.补间动画
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha android:fromAlpha="0"
android:toAlpha="1"
android:duration="4000"/>
</set>
渐入渐出动画