如何在Flutter水平条形图上设置最大高度？

Question

我使用的是水平条形图，可以自动调整条形高度的大小。

https://google.github.io/charts/flutter/example/bar_charts/horizontal_bar_label.html

在本示例中，当我只有一个栏时，我想为该栏固定一个最大高度（例如10像素）。如何配置？

我在这里查看构造函数，但没有找到解决方案 https://pub.dev/documentation/charts_flutter/latest/flutter/BarChart-class.html

      child: SizedBox(
        width: 300.0,
        height: 250.0,
        child: charts.BarChart(
          [
            charts.Series<OrdinalSales, String>(
                id: 'Sales',
                domainFn: (OrdinalSales sales, _) => sales.year,
                measureFn: (OrdinalSales sales, _) => sales.sales,
                data: localData,
                colorFn: (_, __) =>
                    charts.MaterialPalette.green.shadeDefault,
                labelAccessorFn: (OrdinalSales sales, _) =>
                    'Category 1: ${sales.sales.toString()}')
          ],
          animate: true,
          vertical: false,
          barRendererDecorator: new charts.BarLabelDecorator<String>(labelPosition: charts.BarLabelPosition.inside
          ),
          domainAxis:
          new charts.OrdinalAxisSpec(renderSpec: new charts.NoneRenderSpec()),
        ),
      ),

Answer 1

根据以下说明，暂时无法执行此操作：https://github.com/google/charts/issues/167

但是我认为您可以通过创建其他具有透明颜色的项目或更改图表库代码来绕过此操作。

Answer 2

解决方法

您可以尝试将where gcc包装到error: failed to run custom build command for \`backtrace-sys v0.1.37` Caused by: process didn't exit successfully: \`C:\Users\blahblah\AppData\Local\Temp\cargo-installEvEWRS\release\build\backtrace-sys-075604757ab74d2a\build-script-build` (exit code: 1) --- stdout cargo:rustc-cfg=rbt TARGET = Some("x86_64-pc-windows-gnu") OPT_LEVEL = Some("3") HOST = Some("x86_64-pc-windows-gnu") CC_x86_64-pc-windows-gnu = None CC_x86_64_pc_windows_gnu = None HOST_CC = None CC = None CFLAGS_x86_64-pc-windows-gnu = None CFLAGS_x86_64_pc_windows_gnu = None HOST_CFLAGS = None CFLAGS = None CRATE_CC_NO_DEFAULTS = None DEBUG = Some("false") CARGO_CFG_TARGET_FEATURE = Some("fxsr,sse,sse2") running: "gcc.exe" "-O3" "-ffunction-sections" "-fdata-sections" "-m64" "-I" "src/libbacktrace" "-I" "C:\\Users\\BRENDA~1.BUR\\AppData\\Local\\Temp\\cargo-installEvEWRS\\release\\build\\backtra ce-sys-1e77a4d4c3ba2eda\\out" "-fvisibility=hidden" "-DBACKTRACE_SUPPORTED=1" "-DBACKTRACE_USES_MALLOC=1" "-DBACKTRACE_SUPPORTS_THREADS=0" "-DBACKTRACE_SUPPORTS_DATA=0" "-DHAVE_DL_ITERATE_PHDR= 1" "-D_GNU_SOURCE=1" "-D_LARGE_FILES=1" "-Dbacktrace_full=__rbt_backtrace_full" "-Dbacktrace_dwarf_add=__rbt_backtrace_dwarf_add" "-Dbacktrace_initialize=__rbt_backtrace_initialize" "-Dbacktrac e_pcinfo=__rbt_backtrace_pcinfo" "-Dbacktrace_syminfo=__rbt_backtrace_syminfo" "-Dbacktrace_get_view=__rbt_backtrace_get_view" "-Dbacktrace_release_view=__rbt_backtrace_release_view" "-Dbacktra ce_alloc=__rbt_backtrace_alloc" "-Dbacktrace_free=__rbt_backtrace_free" "-Dbacktrace_vector_finish=__rbt_backtrace_vector_finish" "-Dbacktrace_vector_grow=__rbt_backtrace_vector_grow" "-Dbacktr ace_vector_release=__rbt_backtrace_vector_release" "-Dbacktrace_close=__rbt_backtrace_close" "-Dbacktrace_open=__rbt_backtrace_open" "-Dbacktrace_print=__rbt_backtrace_print" "-Dbacktrace_simpl e=__rbt_backtrace_simple" "-Dbacktrace_qsort=__rbt_backtrace_qsort" "-Dbacktrace_create_state=__rbt_backtrace_create_state" "-Dbacktrace_uncompress_zdebug=__rbt_backtrace_uncompress_zdebug" "-D macho_get_view=__rbt_macho_get_view" "-Dmacho_symbol_type_relevant=__rbt_macho_symbol_type_relevant" "-Dmacho_get_commands=__rbt_macho_get_commands" "-Dmacho_try_dsym=__rbt_macho_try_dsym" "-Dm acho_try_dwarf=__rbt_macho_try_dwarf" "-Dmacho_get_addr_range=__rbt_macho_get_addr_range" "-Dmacho_get_uuid=__rbt_macho_get_uuid" "-Dmacho_add=__rbt_macho_add" "-Dmacho_add_symtab=__rbt_macho_a dd_symtab" "-Dmacho_file_to_host_u64=__rbt_macho_file_to_host_u64" "-Dmacho_file_to_host_u32=__rbt_macho_file_to_host_u32" "-Dmacho_file_to_host_u16=__rbt_macho_file_to_host_u16" "-o" "C:\\User s\\BRENDA~1.BUR\\AppData\\Local\\Temp\\cargo-installEvEWRS\\release\\build\\backtrace-sys-1e77a4d4c3ba2eda\\out\\src/libbacktrace/alloc.o" "-c" "src/libbacktrace/alloc.c" --- stderr error occurred: Failed to find tool. Is `gcc.exe` installed? (see https://github.com/alexcrichton/cc-rs#compile-time-requirements for help) 中，并用BarChart包装。

使用伪代码

SizedBox

颤振

SingleChildScrollView

尺寸计算

- SingleChildScrollView - SizedBox - charts.BarChart 的高度可以根据数据数来计算，例如：

SingleChildScrollView(
  child: SizedBox(
    height: 2000,
    child: HorizontalBarLabelChart(
      getData(),
    ),
  ),
),

之前

对于100个元素

之后

对于100个元素（因此高度为SizedBox，因为numerOfElements * 50 ）

Answer 3

尝试执行此操作-

ConstrainedBox(
  constraints: BoxConstraints.expand(height: 50.0), // adjust the height here
  child: Your_chart_here, // place your chart here
),