Question

这是我的代码我得到错误params是null

     viewDynamic = new TextView(getApplicationContext());
     RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.relative);
     RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)viewDynamic.getLayoutParams();
     params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
     params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
     params.addRule(RelativeLayout.ABOVE,userEditTxt.getId());


     viewDynamic.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
     viewDynamic.setText(userEditTxt.getText());
     viewDynamic.setTextColor(Color.RED);
     viewDynamic.setTextScaleX(2);
     viewDynamic.setTextSize(20);
     viewDynamic.setPadding(10, 10, 10, 10);
   //viewDynamic.setVisibility(View.GONE);

     relativeLayout.addView(viewDynamic,params);

Answer 1

如果您还没有将视图添加到任何父容器，或者没有手动调用setLayoutParams，那么getLayoutParams（）将返回null。

在您致电viewDynamic.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); 之前致电viewDynamic.getLayoutParams(); ，或者将视图添加到容器中，以便为视图生成LayoutParams。

我建议你像这样添加你的视图：

viewDynamic = new TextView(getApplicationContext()); RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.relative); RelativeLayout.LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) params.addRule(RelativeLayout.ALIGN_PARENT_LEFT); params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM); params.addRule(RelativeLayout.ABOVE,userEditTxt.getId()); viewDynamic.setText(userEditTxt.getText()); viewDynamic.setTextColor(Color.RED); viewDynamic.setTextScaleX(2); viewDynamic.setTextSize(20); viewDynamic.setPadding(10, 10, 10, 10); relativeLayout.addView(viewDynamic,params);//you attach params to your View here

如何动态设置TextView左侧的父级？

1 个答案: