Pull 练习 demo 示例代码

README.md

@@ -1,5 +1,7 @@
 ![](images/icon.png)
 
+### Fork 自伟大的扔物线大神的练习 demo ,目前已经完成除饼状图以外所有，仅供大家参考~
+
 HenCoder 绘制 1 练习项目
 ===
 
@@ -29,4 +31,4 @@ HenCoder 绘制 1 练习项目
 
 现在的 Android 默认是开启了硬件加速的，而 Canvas 和 Paint 有一些方法是不支持硬件加速的，你需要把它手动关闭才行。硬件加速的支持情况和手动关闭硬件加速的方法你可以看一下这个 Android 的[官方文档](https://developer.android.com/guide/topics/graphics/hardware-accel.html)。
 
-以后我会专门用一节来讲硬件加速和图像的离屏缓冲（off-screen buffer），现在先不多说了。
+以后我会专门用一节来讲硬件加速和图像的离屏缓冲（off-screen buffer），现在先不多说了。

app/src/main/AndroidManifest.xml

@@ -7,7 +7,9 @@
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:supportsRtl="true"
-        android:theme="@style/AppTheme">
+        android:theme="@style/AppTheme"
+        android:hardwareAccelerated="false">
+
         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/com/hencoder/hencoderpracticedraw1/PxDpUtil.java

@@ -0,0 +1,22 @@
+package com.hencoder.hencoderpracticedraw1;
+
+import android.content.Context;
+
+/**
+ * Author: nanchen
+ * Email: [email protected]
+ * Date: 2017-07-11  15:18
+ */
+
+public class PxDpUtil {
+
+    public static int dip2px(Context context, float dipValue) {
+        final float scale = context.getResources().getDisplayMetrics().density;
+        return (int) (dipValue * scale + 0.5f);
+    }
+
+    public static int px2dip(Context context, float pxValue) {
+        final float scale = context.getResources().getDisplayMetrics().density;
+        return (int) (pxValue / scale + 0.5f);
+    }
+}

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice10HistogramView.java

@@ -2,10 +2,14 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
 
+import com.hencoder.hencoderpracticedraw1.PxDpUtil;
+
 public class Practice10HistogramView extends View {
 
     public Practice10HistogramView(Context context) {
@@ -20,11 +24,39 @@ public Practice10HistogramView(Context context, @Nullable AttributeSet attrs, in
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        综合练习
 //        练习内容：使用各种 Canvas.drawXXX() 方法画直方图
+        float width = 70;
+
+        mPaint.setColor(Color.WHITE);
+        mPaint.setStrokeWidth(PxDpUtil.dip2px(getContext(), 1));
+        canvas.drawLine(50, 50, 50, 600, mPaint); // 纵坐标
+
+        canvas.drawLine(50, 600, 600, 600, mPaint); // 横坐标
+
+        mPaint.setTextSize(18);
+        canvas.drawText("Froyo", 85, 650, mPaint);
+        canvas.drawText("GB", 85 + width * 1, 650, mPaint);
+        canvas.drawText("ICS", 85 + width * 2, 650, mPaint);
+        canvas.drawText("JB", 85 + width * 3, 650, mPaint);
+        canvas.drawText("KitKat", 85 + width * 4, 650, mPaint);
+        canvas.drawText("L", 85 + width * 5, 650, mPaint);
+        canvas.drawText("M", 85 + width * 6, 650, mPaint);
+
+        mPaint.setColor(Color.GREEN);
+        mPaint.setStrokeWidth(PxDpUtil.dip2px(getContext(), 20));
+        canvas.drawLine(110, 600, 110, 580, mPaint);
+        canvas.drawLine(110 + width, 600, 110 + width, 550, mPaint);
+        canvas.drawLine(110 + width * 2, 600, 110 + width * 2, 550, mPaint);
+        canvas.drawLine(110 + width * 3, 600, 110 + width * 3, 450, mPaint);
+        canvas.drawLine(110 + width * 4, 600, 110 + width * 4, 300, mPaint);
+        canvas.drawLine(110 + width * 5, 600, 110 + width * 5, 250, mPaint);
+        canvas.drawLine(110 + width * 6, 600, 110 + width * 6, 480, mPaint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice1DrawColorView.java

@@ -2,6 +2,8 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
@@ -20,11 +22,15 @@ public Practice1DrawColorView(Context context, @Nullable AttributeSet attrs, int
         super(context, attrs, defStyleAttr);
     }
 
+    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawColor() 方法把 View 涂成黄色
 //        黄色： Color.YELLOW
+        paint.setColor(Color.YELLOW);
+        canvas.drawPaint(paint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice2DrawCircleView.java

@@ -2,10 +2,15 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
 
+import com.hencoder.hencoderpracticedraw1.PxDpUtil;
+
 public class Practice2DrawCircleView extends View {
 
     public Practice2DrawCircleView(Context context) {
@@ -20,11 +25,34 @@ public Practice2DrawCircleView(Context context, @Nullable AttributeSet attrs, in
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawCircle() 方法画圆
 //        一共四个圆：1.实心圆 2.空心圆 3.蓝色实心圆 4.线宽为 20 的空心圆
+
+        // 1.实心圆
+        mPaint.setColor(Color.BLACK);
+        mPaint.setStyle(Style.FILL);
+        canvas.drawCircle(250,180,150,mPaint);
+
+        // 2.空心圆
+        mPaint.setStyle(Style.STROKE);
+        mPaint.setStrokeWidth(PxDpUtil.dip2px(getContext(),2));
+        canvas.drawCircle(600,180,150,mPaint);
+
+        // 3. 蓝色实心圆
+        mPaint.setColor(Color.BLUE);
+        mPaint.setStyle(Style.FILL);
+        canvas.drawCircle(250,530,150,mPaint);
+
+        // 4.线宽为20的空心圆
+        mPaint.setStyle(Style.STROKE);
+        mPaint.setStrokeWidth(PxDpUtil.dip2px(getContext(),20));
+        mPaint.setColor(Color.BLACK);
+        canvas.drawCircle(600,530,150,mPaint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice3DrawRectView.java

@@ -2,6 +2,8 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
@@ -20,10 +22,16 @@ public Practice3DrawRectView(Context context, @Nullable AttributeSet attrs, int
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawRect() 方法画矩形
+
+        mPaint.setColor(Color.BLACK);
+        canvas.drawRect(300,150,600,450,mPaint);
+
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice4DrawPointView.java

@@ -2,10 +2,15 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Paint.Cap;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
 
+import com.hencoder.hencoderpracticedraw1.PxDpUtil;
+
 public class Practice4DrawPointView extends View {
 
     public Practice4DrawPointView(Context context) {
@@ -20,12 +25,21 @@ public Practice4DrawPointView(Context context, @Nullable AttributeSet attrs, int
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawPoint() 方法画点
 //        一个圆点，一个方点
 //        圆点和方点的切换使用 paint.setStrokeCap(cap)：`ROUND` 是圆点，`BUTT` 或 `SQUARE` 是方点
+
+        mPaint.setStrokeCap(Cap.ROUND);
+        mPaint.setColor(Color.BLACK);
+        mPaint.setStrokeWidth(PxDpUtil.dip2px(getContext(),20));
+        canvas.drawPoint(200,200,mPaint);
+
+        mPaint.setStrokeCap(Cap.BUTT);
+        canvas.drawPoint(400,200,mPaint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice5DrawOvalView.java

@@ -2,6 +2,9 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
+import android.graphics.RectF;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
@@ -19,11 +22,16 @@ public Practice5DrawOvalView(Context context, @Nullable AttributeSet attrs) {
     public Practice5DrawOvalView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
     }
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+    RectF mRectF = new RectF(200,100,600,300);
 
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawOval() 方法画椭圆
+        mPaint.setStyle(Style.FILL);
+//        canvas.drawOval(200,100,300,200,mPaint);
+        canvas.drawOval(mRectF,mPaint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice6DrawLineView.java

@@ -2,10 +2,13 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Paint;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
 
+import com.hencoder.hencoderpracticedraw1.PxDpUtil;
+
 public class Practice6DrawLineView extends View {
 
     public Practice6DrawLineView(Context context) {
@@ -20,10 +23,14 @@ public Practice6DrawLineView(Context context, @Nullable AttributeSet attrs, int
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawLine() 方法画直线
+        mPaint.setStrokeWidth(PxDpUtil.dip2px(getContext(),5));
+        canvas.drawLine(100,100,400,400,mPaint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice7DrawRoundRectView.java

@@ -2,6 +2,9 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
+import android.graphics.RectF;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
@@ -20,10 +23,16 @@ public Practice7DrawRoundRectView(Context context, @Nullable AttributeSet attrs,
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+    RectF mRectF = new RectF(300,100,800,500);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawRoundRect() 方法画圆角矩形
+
+        mPaint.setStyle(Style.FILL);
+        canvas.drawRoundRect(mRectF,50,50,mPaint);
     }
 }

app/src/main/java/com/hencoder/hencoderpracticedraw1/practice/Practice8DrawArcView.java

@@ -2,6 +2,9 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
+import android.graphics.RectF;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
@@ -20,10 +23,23 @@ public Practice8DrawArcView(Context context, @Nullable AttributeSet attrs, int d
         super(context, attrs, defStyleAttr);
     }
 
+    Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+    RectF mRectF = new RectF(200,100,800,500);
+
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
 //        练习内容：使用 canvas.drawArc() 方法画弧形和扇形
+
+        mPaint.setStyle(Style.FILL);
+        canvas.drawArc(mRectF,-130,110,true,mPaint);// 从-130开始，跨度110
+
+        canvas.drawArc(mRectF,20,120,false,mPaint);
+
+        mPaint.setStyle(Style.STROKE);
+        canvas.drawArc(mRectF,180,40,false,mPaint);
+
+
     }
 }