我正在使用CustomPainter
在Flutter中进行绘图,就像这样:
@override
void paint(Canvas canvas, Size size) {
canvas.drawRect(...);
canvas.drawImage(...);
...
}
如何在canvas
上绘制一个Icon
?
我正在使用CustomPainter
在Flutter中进行绘图,就像这样:
@override
void paint(Canvas canvas, Size size) {
canvas.drawRect(...);
canvas.drawImage(...);
...
}
如何在canvas
上绘制一个Icon
?
@Richard Heap和@pskink,基于你们的回答,我尝试了一下并得出了这个结果:谢谢你们,这正是我一直在寻找的。
final icon = Icons.add;
TextPainter textPainter = TextPainter(textDirection: TextDirection.rtl);
textPainter.text = TextSpan(text: String.fromCharCode(icon.codePoint),
style: TextStyle(fontSize: 40.0,fontFamily: icon.fontFamily));
textPainter.layout();
textPainter.paint(canvas, Offset(50.0,50.0));
final icon = Icons.add;
var builder = ui.ParagraphBuilder(ui.ParagraphStyle(
fontFamily: icon.fontFamily,
))
..addText(String.fromCharCode(icon.codePoint));
var para = builder.build();
para.layout(const ui.ParagraphConstraints(width: 60));
canvas.drawParagraph(para, const Offset(20, 20));
只是要补充一个小但重要的细节,如果你正在尝试从外部图标包(如Material Design Icons或FontAwesome)渲染图标,则需要在 TextStyle
中添加package
参数。
final icon = MdiIcons.check;
TextPainter textPainter = TextPainter(textDirection: TextDirection.ltr);
textPainter.text = TextSpan(
text: String.fromCharCode(icon.codePoint),
style: TextStyle(
color: Colors.black,
fontSize: size,
fontFamily: icon.fontFamily,
package: icon.fontPackage, // This line is mandatory for external icon packs
),
);
textPainter.layout();
textPainter.paint(canvas, Offset(x, y));
TextSpan
,请参见 https://www.crossdart.info/p/flutter/0.0.38-dev/src/widgets/icon.dart.html#line-128。 - pskink