Question

我是新来的，所以对于可能违反该平台规则的任何错误，我深表歉意。

我在用背景图片填充Android应用程序时遇到问题。我尝试遵循this，但出现渲染异常。

不使用[SizedBox]类的代码如下：

return Scaffold(
      appBar: new AppBar(title: Text("Progresso nel edilizia")),

      body: SingleChildScrollView(
          child: Container(
            decoration: const BoxDecoration(
              image: DecorationImage(
                image: AssetImage('assets/login_background.jpg'),
                fit: BoxFit.cover
              )
            ),
            child: LoginBody(),
        ) 
      ),
    );

输出：https://ibb.co/0srf6dN

Answer 1

尝试下面的代码

ui <- fluidPage(
  titlePanel("Dynamically generated user interface components"),
  fluidRow(
    selectInput("output_type",
                label = "Select type of output", 
                selected = "table",
                choices = c("table", "barplot", "graph") 
    ),
    uiOutput("diff_outputs")
  )
)

server <- function(input, output){

  output$table <- renderTable({head(women)}) 

  output$barplot <- renderPlot({barplot(women$height)})

  output$scatterplot <- renderPlot({plot(women$height ~ women$weight)})

  output$diff_outputs <- renderUI({
    if (is.null(input$output_type))
      return()
    switch(
      input$output_type,
      "table" = tableOutput("table"),
      "barplot" = plotOutput("barplot"),
      "graph" = plotOutput("scatterplot")
    )
  })

}

shinyApp(ui = ui, server = server)

Answer 2

尝试此操作，但请确保所使用的图像具有正确的宽高比以适合高度。

@override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: new AppBar(title: Text("Progresso nel edilizia")),
      body: SingleChildScrollView(
          child: Container(
        height: MediaQuery.of(context).size.height,
        decoration: const BoxDecoration(
            image: DecorationImage(
                image: AssetImage('assets/login_background.jpg'),
                fit: BoxFit.fitHeight)),
        child: Container(),
      )),
    );
  }

Answer 3

在背景上使用屏幕的整个宽度和高度来将堆栈与容器一起使用。像这样：

return Scaffold(
  appBar: AppBar(title: Text("Progresso nel edilizia")),
  body: Stack(
    children: <Widget>[
      Container(
        width: double.infinity,
        height: double.infinity,
        decoration: const BoxDecoration(
          image: DecorationImage(
            image: AssetImage('assets/login_background.jpg'),
            fit: BoxFit.cover,
          ),
        ),
      ),
      SingleChildScrollView(
        child: LoginBody(),
      ),
    ],
  ),
);

无法用图像填充背景

3 个答案: