一、最简单的自定义View，什么都不显示，但是有View的特性
com.cctvjiatao.customview.MainActivity
packagecom.cctvjiatao.customview;
importandroid.app.Activity;
importandroid.os.Bundle;
publicclassMainActivityextendsActivity {
@Override
protectedvoidonCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
com.cctvjiatao.customview.v1.CustomView1
packagecom.cctvjiatao.customview.v1;
importandroid.content.Context;
importandroid.util.AttributeSet;
importandroid.view.View;
/**
* @作者： 麦典威
* @包名：com.cctvjiatao.customview.v1
* @文件名：CustomView1.java
* @功能： 最简单的自定义View，什么都不显示，但是有View的特性
*/
publicclassCustomView1extendsView {
publicCustomView1(Context context) {
super(context);
}
publicCustomView1(Context context, AttributeSet attrs) {
super(context, attrs);
}
}
activity_main.xml
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00ff00">
AndroidManifest.xml
package="com.cctvjiatao.customview"
android:versionCode="1"
android:versionName="1.0">
android:minSdkVersion="14"
android:targetSdkVersion="21"/>
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme">
android:name=".MainActivity"
android:label="@string/app_name">
效果图暂略。
二、自定义View，显示一行文字。注意:drawText的坐标是 “左下” 坐标。
com.cctvjiatao.customview.MainActivity 同一
AndroidManifest.xml 同一
activity_main.xml
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00ff00"
android:visibility="gone">
android:layout_width="match_parent"
android:layout_height="match_parent">
com.cctvjiatao.customview.v2.CustomView1
packagecom.cctvjiatao.customview.v2;
importandroid.content.Context;
importandroid.graphics.Canvas;
importandroid.graphics.Paint;
importandroid.util.AttributeSet;
importandroid.view.View;
/**
* @作者： 麦典威
* @包名：com.cctvjiatao.customview.v2
* @文件名：CustomView2.java
* @功能： 自定义View，显示一行文字。注意:drawText的坐标是 “左下” 坐标。
*/
publicclassCustomView1extendsView {
publicCustomView1(Context context, AttributeSet attrs) {
super(context, attrs);
}
publicCustomView1(Context context) {
super(context);
}
@Override
protectedvoidonDraw(Canvas canvas) {
Paint paint =newPaint();
// canvas.drawText("This is a canvas", 0, 0, paint);//这样写不会显示文字，因为文字的左下坐标是（0，0）
canvas.drawText("This is a canvas,坐标为左下（0，50）",0,50, paint);// (字符，左坐标，下坐标，画笔)
paint.setTextSize(30);//设置画笔大小，即字体大小
canvas.drawText("This is a canvas，坐标为左下（0，30）",0,30, paint);// (字符，左坐标，下坐标，画笔)
}
}
效果图暂略。
三、自定义View，画线、矩形、圆角矩形、圆形
com.cctvjiatao.customview.MainActivity 同一
AndroidManifest.xml 同一
activity_main.xml
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00ff00"
android:visibility="gone">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
android:layout_width="match_parent"
android:layout_height="match_parent">
com.cctvjiatao.customview.v2.CustomView2
packagecom.cctvjiatao.customview.v2;
importandroid.content.Context;
importandroid.graphics.Canvas;
importandroid.graphics.Paint;
importandroid.graphics.Rect;
importandroid.graphics.RectF;
importandroid.graphics.Paint.Style;
importandroid.util.AttributeSet;
importandroid.view.View;
/**
* @作者： 麦典威
* @包名：com.cctvjiatao.customview.v2
* @文件名：CustomView2.java
* @功能： 自定义View，画线、矩形、圆角矩形、圆形
*/
publicclassCustomView2extendsView {
publicCustomView2(Context context, AttributeSet attrs) {
super(context, attrs);
}
publicCustomView2(Context context) {
super(context);
}
@Override
protectedvoidonDraw(Canvas canvas) {
Paint paint =newPaint();
paint.setTextSize(10);
paint.setColor(0xffff0000);
// 画直线
canvas.drawLine(0,10,200,10, paint);
// 画斜线
canvas.drawLine(0,10,200,60, paint);
// 画矩形(Rect)
Rect rect =newRect(0,80,100,160);
canvas.drawRect(rect, paint);
// 画矩形(RectF)
RectF rectf =newRectF(150,80,250,160);
canvas.drawRect(rectf, paint);
// 画矩形(坐标)
canvas.drawRect(300,80,400,160, paint);
// 画圆角矩形(RectF)
RectF rectrf =newRectF(10,180,110,250);
canvas.drawRoundRect(rectrf,10,10, paint);
// 画圆角矩形(RectF)
canvas.drawRoundRect(120,180,220,250,10,10, paint);
// 画圆形
canvas.drawCircle(100,350,50, paint);
paint.setStyle(Style.STROKE);
canvas.drawCircle(210,350,50, paint);
paint.setStyle(Style.FILL_AND_STROKE);
canvas.drawCircle(320,350,50, paint);
paint.setStyle(Style.FILL);
canvas.drawCircle(430,350,50, paint);
}
}
效果图暂略。
四、自定义View，画图像
com.cctvjiatao.customview.MainActivity 同一
AndroidManifest.xml 同一
activity_main.xml
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00ff00"
android:visibility="gone">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
android:layout_width="match_parent"
android:layout_height="match_parent">
com.cctvjiatao.customview.v2.CustomView3
packagecom.cctvjiatao.customview.v2;
importcom.cctvjiatao.customview.R;
importandroid.content.Context;
importandroid.graphics.Bitmap;
importandroid.graphics.BitmapFactory;
importandroid.graphics.Canvas;
importandroid.graphics.Paint;
importandroid.util.AttributeSet;
importandroid.view.View;
/**
* @作者： 麦典威
* @包名：com.cctvjiatao.customview.v2
* @文件名：CustomView3.java
* @功能： 自定义View，画图像
*/
publicclassCustomView3extendsView {
privateBitmap bitmap;
publicCustomView3(Context context, AttributeSet attrs) {
super(context, attrs);
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
}
publicCustomView3(Context context) {
super(context);
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
}
@Override
protectedvoidonDraw(Canvas canvas) {
Paint paint =newPaint();
canvas.drawBitmap(bitmap,0,35, paint);
}
}
效果图暂略
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