1、自定義View
android中可能遇到很多需求要求自定義view,一般github上都有各種各樣的酷炫效果自定義view,特別是儀表盤,柱狀圖,餅狀圖都有,但還是不免遇到一些特別的需求,自定義樣式難以修改開源庫,因此還是需要自己來實現。接下來記錄自己一點一點學習自定義view的過程。接下來主要實現這樣的效果(簡單的實現畫圓,和簡單的動畫效果)
項目目錄結構
2、自定義view中構造方法
構造方法用來初始化view,一般的定義的view比如圓的寬,高,圓的顏色等,都是在我們xml文件中配置的,因此,我們必須重寫帶有AttributeSet的構造方法
/**
* 當需要在xml中聲明此控件,則需要實現此構造函數
* 並且在構造函數中把自定義的屬性與控件的數據成員連接起來
*
* @param context
* @param attrs
*/
public View1(Context context, AttributeSet attrs) {
super(context, attrs);
//如果xml文件中沒有文件,則使用後面默認值;
paintOut = new Paint();
paintIn=new Paint();
//從attrs讀取屬性
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.MyView1);
this.cicle_in_color = typedArray.getColor(R.styleable.MyView1_cicle_in_color, Color.BLACK);
this.cicle_in_radius = typedArray.getDimension(R.styleable.MyView1_cicle_in_radius, 100);
this.cicle_in_StrokeWidth = typedArray.getDimension(R.styleable.MyView1_cicle_in_StrokeWidth, 5);
this.cicle_out_color = typedArray.getColor(R.styleable.MyView1_cicle_out_color, Color.BLACK);
this.cicle_out_radius = typedArray.getDimension(R.styleable.MyView1_cicle_out_radius, 30);
this.cicle_out_StrokeWidth = typedArray.getDimension(R.styleable.MyView1_cicle_out_StrokeWidth, 5);
//打開抗鋸齒
paintOut.setAntiAlias(true);
//設置xml文件中的屬性
paintOut.setColor(cicle_out_color);
paintOut.setStyle(Paint.Style.STROKE);
paintOut.setStrokeWidth(cicle_out_StrokeWidth);
paintIn.setColor(cicle_in_color);
paintIn.setStyle(Paint.Style.STROKE);
paintIn.setStrokeWidth(cicle_in_StrokeWidth);
//回收TypedArray,以便後面重用
typedArray.recycle();
}
3、在xml文件中配置自定義view的屬性、
在values下新建attrs.xml文件
<?xml version="1.0" encoding="utf-8"?>
<resources>
//自定義屬性名,定義公共屬性
<attr name="textSize" format="dimension"></attr>
<attr name="textTitle" format="string"></attr>
<attr name="textColor" format="color"></attr>
<attr name="cicle_color" format="color"></attr>
<attr name="cicle_radius" format="dimension"></attr>
<declare-styleable name="MyView1">
<attr name="cicle_color"></attr>
<attr name="cicle_out_color" format="color"></attr>
<attr name="cicle_out_radius" format="dimension"></attr>
<attr name="cicle_out_StrokeWidth" format="dimension"></attr>
<attr name="cicle_in_color" format="color"></attr>
<attr name="cicle_in_radius" format="dimension"></attr>
<attr name="cicle_in_StrokeWidth" format="dimension"></attr>
</declare-styleable>
<declare-styleable name="MyView2">
<attr name="textSize"></attr>
<attr name="textTitle"></attr>
<attr name="textColor"></attr>
<attr name="cicle_color"></attr>
<attr name="cicle_StrokeWidth" format="dimension"></attr>
<attr name="cicle_radius"></attr>
</declare-styleable>
</resources>
這樣,就可以在界面的xml文件中配置這些屬性,添加命名空間和聲明的屬性名稱
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin">
<view.viewActivity1.View1
android:layout_width="100dp"
android:layout_height="100dp"
custom:cicle_in_StrokeWidth="5dp"
custom:cicle_in_color="#00ff00"
custom:cicle_in_radius="20dp"
custom:cicle_out_StrokeWidth="5dp"
custom:cicle_out_color="#ff0000"
custom:cicle_out_radius="45dp"
/>
<view.viewActivity1.View2
android:id="@+id/view2"
android:layout_width="100dp"
android:layout_height="100dp"
custom:cicle_StrokeWidth="5dp"
custom:cicle_color="#0000ff" />
</LinearLayout>
4、自定義view的主要代碼,在代碼中做詳解
1、畫圓的主要代碼
package view.viewActivity1;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
import com.example.cusotmerview.R;
/**
* Created by yuxiaogang on 2017/2/23.
*/
public class View1 extends View {
private Paint paintOut;
private Paint paintIn;
private int cicle_in_color;
private float cicle_in_radius;
private float cicle_in_StrokeWidth;
private int cicle_out_color;
private float cicle_out_radius;
private float cicle_out_StrokeWidth;
public View1(Context context) {
super(context);
}
/**
* 當需要在xml中聲明此控件,則需要實現此構造函數
* 並且在構造函數中把自定義的屬性與控件的數據成員連接起來
*
* @param context
* @param attrs
*/
public View1(Context context, AttributeSet attrs) {
super(context, attrs);
//如果xml文件中沒有文件,則使用後面默認值;
paintOut = new Paint();
paintIn=new Paint();
//從attrs讀取屬性
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.MyView1);
this.cicle_in_color = typedArray.getColor(R.styleable.MyView1_cicle_in_color, Color.BLACK);
this.cicle_in_radius = typedArray.getDimension(R.styleable.MyView1_cicle_in_radius, 100);
this.cicle_in_StrokeWidth = typedArray.getDimension(R.styleable.MyView1_cicle_in_StrokeWidth, 5);
this.cicle_out_color = typedArray.getColor(R.styleable.MyView1_cicle_out_color, Color.BLACK);
this.cicle_out_radius = typedArray.getDimension(R.styleable.MyView1_cicle_out_radius, 30);
this.cicle_out_StrokeWidth = typedArray.getDimension(R.styleable.MyView1_cicle_out_StrokeWidth, 5);
//打開抗鋸齒
paintOut.setAntiAlias(true);
//設置xml文件中的屬性
paintOut.setColor(cicle_out_color);
paintOut.setStyle(Paint.Style.STROKE);
paintOut.setStrokeWidth(cicle_out_StrokeWidth);
paintIn.setColor(cicle_in_color);
paintIn.setStyle(Paint.Style.STROKE);
paintIn.setStrokeWidth(cicle_in_StrokeWidth);
//回收TypedArray,以便後面重用
typedArray.recycle();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
/**
* 第一個參數:圓心x座標
* 第二個參數:圓心y座標
* 第三個參數:半徑
* 第四個參數:paint畫筆
*/
canvas.drawCircle(100, 100, cicle_out_radius, paintOut);
canvas.drawCircle(100, 100, cicle_in_radius, paintIn);
}
}
2、畫圓有動畫效果的代碼
package view.viewActivity1;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
import com.example.cusotmerview.R;
/**
* Created by yuxiaogang on 2017/2/23.
*/
public class View2 extends View {
private Paint circlePaint;
private RectF circleRect;
private int cicle_out_color;
private float cicle_out_radius;
private float cicle_out_StrokeWidth;
private int mCurrentPercent;
public int getmTargetPercent() {
return mTargetPercent;
}
public void setmTargetPercent(int mTargetPercent) {
this.mTargetPercent = mTargetPercent;
}
private int mTargetPercent;
private float mCurrentAngle;
private float mStartSweepValue;
public View2(Context context) {
super(context);
}
/**
* 當需要在xml中聲明此控件,則需要實現此構造函數
* 並且在構造函數中把自定義的屬性與控件的數據成員連接起來
*
* @param context
* @param attrs
*/
public View2(Context context, AttributeSet attrs) {
super(context, attrs);
//如果xml文件中沒有文件,則使用後面默認值;
circlePaint = new Paint();
//從attrs讀取屬性
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.MyView2);
this.cicle_out_color = typedArray.getColor(R.styleable.MyView2_cicle_color, Color.BLACK);
this.cicle_out_radius = typedArray.getDimension(R.styleable.MyView2_cicle_radius, 30);
this.cicle_out_StrokeWidth = typedArray.getDimension(R.styleable.MyView2_cicle_StrokeWidth, 5);
//回收TypedArray,以便後面重用
typedArray.recycle();
init();
}
private void init() {
mStartSweepValue = 180;
//當前角度
mCurrentAngle = 0;
//當前百分比
mCurrentPercent = 0;
circleRect = new RectF(20, 20, getWidth() - 20, getWidth() - 20);
}
public void setNumber(int size) {
mCurrentPercent = 0;
mTargetPercent = size;
mCurrentAngle = 0;
postInvalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//打開抗鋸齒
circlePaint.setAntiAlias(true);
//設置xml文件中的屬性
circlePaint.setColor(cicle_out_color);
circlePaint.setStyle(Paint.Style.STROKE);
circlePaint.setStrokeWidth(cicle_out_StrokeWidth);
// 通過上下左右4個邊的座標來表示一個矩形,畫圓就在這個矩形區域內;
circleRect = new RectF(10, 10, getWidth() - 10, getWidth() - 10);
/**
* drawArc()
* 第一個參數:圓弧外的輪廓區域
* 第二個參數,圓弧開始的角度
* 第三個參數,圓弧順時針掃過的角度
* 第四個參數, 如果爲True時,在繪製圓弧時將圓心包括在內,通常用來繪製扇形
* 第五個參數,畫布
*/
canvas.drawArc(circleRect, mStartSweepValue, mCurrentAngle, false, circlePaint);
if (mCurrentPercent < mTargetPercent) {
//當前百分比+1
mCurrentPercent += 2;
//當前角度+360
mCurrentAngle += 7.2;
//每100ms重畫一次
postInvalidateDelayed(100);
}
}
}